MC908JB8JDWER

MC68HC908JB8 MC68HC08JB8 MC68HC08JT8 Technical Data M68HC08 Microcontrollers MC68HC908JB8/D Rev. 2.3 9/2005 freescale.com MC68HC908JB8 MC68HC08JB8 MC68HC08JT8 Technical Data To provide the most up-to-date information, the revision of our documents on the World Wide Web will be the most current. Your printed copy may be an earlier revision. To verify you have the latest information available, refer to: http://freescale.com The following revision history table summarizes changes contained in this document. For your convenience, the page number designators have been linked to the appropriate location. Freescale and the Freescale logo are registered trademarks of Freescale Semiconductor, Inc. This product incorporates SuperFlash® technology licensed from SST. © Freescale Semiconductor, Inc., 2005. All rights reserved. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Technical Data 3 Revision History Revision History Date Revision Level September 2005 2.3 Added Pb-free parts. August 2005 2.2 Updated to meet Freescale identity guidelines. Page Number(s) Description 267, 284 Throughout 4.9 ROM-Resident Routines — Removed block erase references for ROM-resident routines. December 2003 61 9.8.8 USB Control Register 3 — Clarified bit descriptions for OSTALL0 and ISTALL0. 149, 150 9.8.11 USB Status Register 1 — Clarified bit descriptions for TXACK, TXNAK, and TXSTL. 153 Section 19. Mechanical Specifications — Replaced incorrect 44-pin QFP drawing, case 824E to case 824A. 263 2.1 Corrected PTD6 and PTD7: not direct LED drive pins. February 2002 Technical Data 4 2 28, 210, 217 Removed incorrect RX1E text from USB control register 1. 146 Corrected Figure 9-30 for USB module. 159 Corrected timer discrepancies throughout Section 11. Timer Interface Module (TIM). 177 Added Table 12-1 . Port Control Register Bits Summary. 201 Changed pullup resistor limits for D– and I/O ports in 18.6 DC Electrical Characteristics. 256 Added mechanical drawing for 20-pin SOIC package. 266 Added Appendix A. MC68HC08JB8 — ROM part. 269 Added Appendix B. MC68HC08JT8 — low-voltage ROM part. 277 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Technical Data — MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 List of Sections Section 1. General Description . . . . . . . . . . . . . . . . . . . . 27 Section 2. Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Section 3. Random-Access Memory (RAM) . . . . . . . . . . 51 Section 4. FLASH Memory . . . . . . . . . . . . . . . . . . . . . . . . 53 Section 5. Configuration Register (CONFIG) . . . . . . . . . 65 Section 6. Central Processor Unit (CPU) . . . . . . . . . . . . 69 Section 7. Oscillator (OSC) . . . . . . . . . . . . . . . . . . . . . . . 89 Section 8. System Integration Module (SIM) . . . . . . . . . 93 Section 9. Universal Serial Bus Module (USB) . . . . . . . 117 Section 10. Monitor ROM (MON) . . . . . . . . . . . . . . . . . . 163 Section 11. Timer Interface Module (TIM) . . . . . . . . . . . 177 Section 12. Input/Output Ports (I/O) . . . . . . . . . . . . . . . 199 Section 13. External Interrupt (IRQ) . . . . . . . . . . . . . . . 219 Section 14. Keyboard Interrupt Module (KBI). . . . . . . . 227 Section 15. Computer Operating Properly (COP) . . . . 237 Section 16. Low Voltage Inhibit (LVI) . . . . . . . . . . . . . . 243 Section 17. Break Module (BREAK) . . . . . . . . . . . . . . . 245 Section 18. Electrical Specifications. . . . . . . . . . . . . . . 253 Section 19. Mechanical Specifications . . . . . . . . . . . . . 263 Section 20. Ordering Information . . . . . . . . . . . . . . . . . 267 Appendix A. MC68HC08JB8 . . . . . . . . . . . . . . . . . . . . . . 269 Appendix B. MC68HC08JT8 . . . . . . . . . . . . . . . . . . . . . . 277 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor List of Sections Technical Data 5 List of Sections Technical Data 6 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 List of Sections Freescale Semiconductor Technical Data — MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 Table of Contents Section 1. General Description 1.1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27 1.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 1.3 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 1.4 MCU Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 1.5 Pin Assignments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 1.5.1 Power Supply Pins (VDD, VSS) . . . . . . . . . . . . . . . . . . . . . . . 34 1.5.2 Voltage Regulator Out (VREG) . . . . . . . . . . . . . . . . . . . . . . . 34 1.5.3 Oscillator Pins (OSC1 and OSC2) . . . . . . . . . . . . . . . . . . . . 35 1.5.4 External Reset Pin (RST) . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 1.5.5 External Interrupt Pins (IRQ, PTE4/D–) . . . . . . . . . . . . . . . . 35 1.5.6 Port A Input/Output (I/O) Pins (PTA7/KBA7–PTA0/KBA0). . 36 1.5.7 Port B (I/O) Pins (PTB7–PTB0) . . . . . . . . . . . . . . . . . . . . . . 36 1.5.8 Port C I/O Pins (PTC7–PTC0) . . . . . . . . . . . . . . . . . . . . . . . 36 1.5.9 Port D I/O Pins (PTD7–PTD0) . . . . . . . . . . . . . . . . . . . . . . . 36 1.5.10 Port E I/O Pins (PTE4/D–, PTE3/D+, PTE2/TCH1, PTE1/TCH0, PTE0/TCLK). . . . . . . . . . . . . . . . . . . . . . . . 36 Section 2. Memory Map 2.1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39 2.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 2.3 I/O Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 2.4 Monitor ROM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Table of Contents Technical Data 7 Table of Contents Section 3. Random-Access Memory (RAM) 3.1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51 3.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 3.3 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51 Section 4. FLASH Memory 4.1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53 4.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 4.3 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54 4.4 FLASH Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 4.5 FLASH Block Erase Operation . . . . . . . . . . . . . . . . . . . . . . . . . 56 4.6 FLASH Mass Erase Operation . . . . . . . . . . . . . . . . . . . . . . . . . 57 4.7 FLASH Program Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . .58 4.8 FLASH Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60 4.8.1 FLASH Block Protect Register . . . . . . . . . . . . . . . . . . . . . . . 60 4.9 ROM-Resident Routines. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 4.9.1 Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 4.9.2 ERASE Routine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 4.9.3 PROGRAM Routine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 4.9.4 VERIFY Routine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 Section 5. Configuration Register (CONFIG) Technical Data 8 5.1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .65 5.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 5.3 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .66 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Table of Contents Freescale Semiconductor Table of Contents Section 6. Central Processor Unit (CPU) 6.1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .69 6.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 6.3 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 6.4 CPU Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 6.4.1 Accumulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 6.4.2 Index Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 6.4.3 Stack Pointer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 6.4.4 Program Counter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 6.4.5 Condition Code Register . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 6.5 Arithmetic/Logic Unit (ALU) . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 6.6 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 6.6.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .76 6.6.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .77 6.7 CPU During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . 77 6.8 Instruction Set Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 6.9 Opcode Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 Section 7. Oscillator (OSC) 7.1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .89 7.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 7.3 Oscillator External Connections . . . . . . . . . . . . . . . . . . . . . . . .90 7.4 I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 7.4.1 Crystal Amplifier Input Pin (OSC1). . . . . . . . . . . . . . . . . . . . 91 7.4.2 Crystal Amplifier Output Pin (OSC2) . . . . . . . . . . . . . . . . . . 91 7.4.3 Oscillator Enable Signal (SIMOSCEN). . . . . . . . . . . . . . . . . 91 7.4.4 External Clock Source (OSCXCLK) . . . . . . . . . . . . . . . . . . . 91 7.4.5 Oscillator Out (OSCOUT). . . . . . . . . . . . . . . . . . . . . . . . . . . 92 7.5 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 7.5.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .92 7.5.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .92 7.6 Oscillator During Break Mode. . . . . . . . . . . . . . . . . . . . . . . . . . 92 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Table of Contents Technical Data 9 Table of Contents Section 8. System Integration Module (SIM) 8.1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .93 8.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94 8.3 SIM Bus Clock Control and Generation . . . . . . . . . . . . . . . . . . 96 8.3.1 Bus Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 8.3.2 Clock Startup from POR or LVI Reset . . . . . . . . . . . . . . . . . 97 8.3.3 Clocks in Stop Mode and Wait Mode . . . . . . . . . . . . . . . . . . 97 8.4 Reset and System Initialization. . . . . . . . . . . . . . . . . . . . . . . . . 97 8.4.1 External Pin Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98 8.4.2 Active Resets from Internal Sources . . . . . . . . . . . . . . . . . . 99 8.4.2.1 Power-On Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .100 8.4.2.2 Computer Operating Properly (COP) Reset. . . . . . . . . . 101 8.4.2.3 Illegal Opcode Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . 101 8.4.2.4 Illegal Address Reset . . . . . . . . . . . . . . . . . . . . . . . . . . .101 8.4.2.5 Low-Voltage Inhibit (LVI) Reset . . . . . . . . . . . . . . . . . . . 102 8.4.2.6 Universal Serial Bus Reset . . . . . . . . . . . . . . . . . . . . . . 102 8.4.2.7 Registers Values After Different Resets. . . . . . . . . . . . . 102 8.5 SIM Counter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 8.5.1 SIM Counter During Power-On Reset . . . . . . . . . . . . . . . . 103 8.5.2 SIM Counter During Stop Mode Recovery . . . . . . . . . . . . . 104 8.5.3 SIM Counter and Reset States. . . . . . . . . . . . . . . . . . . . . . 104 8.6 Exception Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .104 8.6.1 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104 8.6.1.1 Hardware Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 8.6.1.2 SWI Instruction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108 8.6.2 Interrupt Status Registers. . . . . . . . . . . . . . . . . . . . . . . . . . 108 8.6.2.1 Interrupt Status Register 1 . . . . . . . . . . . . . . . . . . . . . . . 109 8.6.3 Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 8.6.4 Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 8.6.5 Status Flag Protection in Break Mode . . . . . . . . . . . . . . . . 110 8.7 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110 8.7.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .110 8.7.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .112 8.8 Technical Data 10 SIM Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Table of Contents Freescale Semiconductor Table of Contents 8.8.1 8.8.2 8.8.3 Break Status Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113 Reset Status Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 Break Flag Control Register . . . . . . . . . . . . . . . . . . . . . . .116 Section 9. Universal Serial Bus Module (USB) 9.1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .117 9.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118 9.3 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119 9.4 Pin Name Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120 9.5 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .124 9.5.1 USB Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 9.5.1.1 Sync Pattern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126 9.5.1.2 Packet Identifier Field . . . . . . . . . . . . . . . . . . . . . . . . . . 127 9.5.1.3 Address Field (ADDR) . . . . . . . . . . . . . . . . . . . . . . . . . . 128 9.5.1.4 Endpoint Field (ENDP). . . . . . . . . . . . . . . . . . . . . . . . . . 128 9.5.1.5 Cyclic Redundancy Check (CRC) . . . . . . . . . . . . . . . . . 128 9.5.1.6 End-of-Packet (EOP) . . . . . . . . . . . . . . . . . . . . . . . . . . .128 9.5.2 Reset Signaling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129 9.5.3 Suspend . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130 9.5.4 Resume After Suspend . . . . . . . . . . . . . . . . . . . . . . . . . . . 131 9.5.4.1 Host Initiated Resume . . . . . . . . . . . . . . . . . . . . . . . . . . 131 9.5.4.2 USB Reset Signalling. . . . . . . . . . . . . . . . . . . . . . . . . . .131 9.5.4.3 Remote Wakeup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .131 9.5.5 Low-Speed Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132 9.6 Clock Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132 9.7 Hardware Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 9.7.1 Voltage Regulator. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 9.7.2 USB Transceiver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 9.7.2.1 Output Driver Characteristics . . . . . . . . . . . . . . . . . . . . . 134 9.7.2.2 Low Speed (1.5 Mbps) Driver Characteristics . . . . . . . . 134 9.7.2.3 Receiver Data Jitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135 9.7.2.4 Data Source Jitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135 9.7.2.5 Data Signal Rise and Fall Time . . . . . . . . . . . . . . . . . . . 136 9.7.3 USB Control Logic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Table of Contents Technical Data 11 Table of Contents 9.8 I/O Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137 9.8.1 USB Address Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138 9.8.2 USB Interrupt Register 0 . . . . . . . . . . . . . . . . . . . . . . . . . . 139 9.8.3 USB Interrupt Register 1 . . . . . . . . . . . . . . . . . . . . . . . . . . 141 9.8.4 USB Interrupt Register 2 . . . . . . . . . . . . . . . . . . . . . . . . . . 144 9.8.5 USB Control Register 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . 145 9.8.6 USB Control Register 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . 146 9.8.7 USB Control Register 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . 147 9.8.8 USB Control Register 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . 149 9.8.9 USB Control Register 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . 151 9.8.10 USB Status Register 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152 9.8.11 USB Status Register 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153 9.8.12 USB Endpoint 0 Data Registers . . . . . . . . . . . . . . . . . . . . . 154 9.8.13 USB Endpoint 1 Data Registers . . . . . . . . . . . . . . . . . . . . . 155 9.8.14 USB Endpoint 2 Data Registers . . . . . . . . . . . . . . . . . . . . . 156 9.9 USB Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157 9.9.1 USB End-of-Transaction Interrupt . . . . . . . . . . . . . . . . . . . 157 9.9.1.1 Receive Control Endpoint 0 . . . . . . . . . . . . . . . . . . . . . . 158 9.9.1.2 Transmit Control Endpoint 0 . . . . . . . . . . . . . . . . . . . . . 160 9.9.1.3 Transmit Endpoint 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161 9.9.1.4 Transmit Endpoint 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162 9.9.1.5 Receive Endpoint 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162 9.9.2 Resume Interrupt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162 9.9.3 End-of-Packet Interrupt . . . . . . . . . . . . . . . . . . . . . . . . . . . 162 Section 10. Monitor ROM (MON) 10.1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .163 10.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163 10.3 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164 10.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .164 10.4.1 Entering Monitor Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166 10.4.2 Baud Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .169 10.4.3 Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170 10.4.4 Echoing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170 10.4.5 Break Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171 Technical Data 12 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Table of Contents Freescale Semiconductor Table of Contents 10.4.6 10.5 Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171 Security. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175 Section 11. Timer Interface Module (TIM) 11.1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .177 11.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178 11.3 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178 11.4 Pin Name Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178 11.5 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .179 11.5.1 TIM Counter Prescaler . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181 11.5.2 Input Capture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181 11.5.3 Output Compare. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181 11.5.3.1 Unbuffered Output Compare . . . . . . . . . . . . . . . . . . . . . 182 11.5.3.2 Buffered Output Compare . . . . . . . . . . . . . . . . . . . . . . .183 11.5.4 Pulse Width Modulation (PWM) . . . . . . . . . . . . . . . . . . . . . 183 11.5.4.1 Unbuffered PWM Signal Generation . . . . . . . . . . . . . . . 184 11.5.4.2 Buffered PWM Signal Generation . . . . . . . . . . . . . . . . . 185 11.5.4.3 PWM Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186 11.6 Interrupts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .187 11.7 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187 11.7.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .188 11.7.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .188 11.8 TIM During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . 188 11.9 I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189 11.9.1 TIM Clock Pin (PTE0/TCLK) . . . . . . . . . . . . . . . . . . . . . . .189 11.9.2 TIM Channel I/O Pins (PTE1/TCH0:PTE2/TCH1) . . . . . . . 189 11.10 I/O Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189 11.10.1 TIM Status and Control Register . . . . . . . . . . . . . . . . . . . . 190 11.10.2 TIM Counter Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192 11.10.3 TIM Counter Modulo Registers . . . . . . . . . . . . . . . . . . . . . 193 11.10.4 TIM Channel Status and Control Registers . . . . . . . . . . . . 194 11.10.5 TIM Channel Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . 198 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Table of Contents Technical Data 13 Table of Contents Section 12. Input/Output Ports (I/O) 12.1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .199 12.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199 12.3 Port A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202 12.3.1 Port A Data Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202 12.3.2 Data Direction Register A. . . . . . . . . . . . . . . . . . . . . . . . . . 203 12.4 Port B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204 12.4.1 Port B Data Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204 12.4.2 Data Direction Register B. . . . . . . . . . . . . . . . . . . . . . . . . . 205 12.5 Port C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207 12.5.1 Port C Data Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207 12.5.2 Data Direction Register C. . . . . . . . . . . . . . . . . . . . . . . . . . 208 12.6 Port D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209 12.6.1 Port D Data Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210 12.6.2 Data Direction Register D. . . . . . . . . . . . . . . . . . . . . . . . . . 211 12.7 Port E . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212 12.7.1 Port E Data Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213 12.7.2 Data Direction Register E. . . . . . . . . . . . . . . . . . . . . . . . . . 215 12.8 Port Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216 12.8.1 Port Option Control Register . . . . . . . . . . . . . . . . . . . . . . .217 Section 13. External Interrupt (IRQ) Technical Data 14 13.1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .219 13.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219 13.3 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219 13.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .220 13.5 IRQ Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222 13.6 PTE4/D– Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223 13.7 IRQ Module During Break Interrupts . . . . . . . . . . . . . . . . . . . 223 13.8 IRQ Status and Control Register . . . . . . . . . . . . . . . . . . . . . . 224 13.9 IRQ Option Control Register. . . . . . . . . . . . . . . . . . . . . . . . . . 225 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Table of Contents Freescale Semiconductor Table of Contents Section 14. Keyboard Interrupt Module (KBI) 14.1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .227 14.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227 14.3 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228 14.4 Pin Name Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228 14.5 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .230 14.6 Keyboard Initialization. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231 14.7 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232 14.7.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .232 14.7.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .232 14.8 Keyboard Module During Break Interrupts . . . . . . . . . . . . . . . 233 14.9 I/O Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233 14.9.1 Keyboard Status and Control Register. . . . . . . . . . . . . . . . 233 14.9.2 Keyboard Interrupt Enable Register . . . . . . . . . . . . . . . . . . 235 Section 15. Computer Operating Properly (COP) 15.1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .237 15.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237 15.3 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .238 15.4 I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239 15.4.1 OSCXCLK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .239 15.4.2 STOP Instruction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239 15.4.3 COPCTL Write . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .239 15.4.4 Power-On Reset. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240 15.4.5 Internal Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240 15.4.6 Reset Vector Fetch. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240 15.4.7 COPD (COP Disable). . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240 15.4.8 COPRS (COP Rate Select) . . . . . . . . . . . . . . . . . . . . . . . . 240 15.5 COP Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241 15.6 Interrupts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .241 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Table of Contents Technical Data 15 Table of Contents 15.7 Monitor Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .241 15.8 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242 15.8.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .242 15.8.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .242 15.9 COP Module During Break Mode . . . . . . . . . . . . . . . . . . . . . . 242 Section 16. Low Voltage Inhibit (LVI) 16.1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .243 16.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243 16.3 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .243 16.4 LVI Control Register (CONFIG) . . . . . . . . . . . . . . . . . . . . . . .244 16.5 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244 16.5.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .244 16.5.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .244 Section 17. Break Module (BREAK) 17.1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .245 17.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245 17.3 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 246 17.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .246 17.4.1 Flag Protection During Break Interrupts . . . . . . . . . . . . . . . 248 17.4.2 CPU During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . .248 17.4.3 TIM During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . 248 17.4.4 COP During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . 248 17.5 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248 17.5.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .248 17.5.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .249 17.6 Break Module Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249 17.6.1 Break Status and Control Register. . . . . . . . . . . . . . . . . . . 249 17.6.2 Break Address Registers . . . . . . . . . . . . . . . . . . . . . . . . . . 250 17.6.3 Break Status Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250 17.6.4 Break Flag Control Register (BFCR) . . . . . . . . . . . . . . . . . 252 Technical Data 16 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Table of Contents Freescale Semiconductor Table of Contents Section 18. Electrical Specifications 18.1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .253 18.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253 18.3 Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . 254 18.4 Functional Operating Range. . . . . . . . . . . . . . . . . . . . . . . . . . 255 18.5 Thermal Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255 18.6 DC Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . 256 18.7 Control Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257 18.8 Oscillator Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257 18.9 USB DC Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . 258 18.10 USB Low-Speed Source Electrical Characteristics . . . . . . . . 259 18.11 USB Signaling Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260 18.12 TImer Interface Module Characteristics . . . . . . . . . . . . . . . . . 260 18.13 Memory Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261 Section 19. Mechanical Specifications 19.1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .263 19.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263 19.3 44-Pin Plastic Quad Flat Pack (QFP) . . . . . . . . . . . . . . . . . . . 264 19.4 28-Pin Small Outline Integrated Circuit (SOIC) . . . . . . . . . . . 265 19.5 20-Pin Dual In-Line Package (PDIP) . . . . . . . . . . . . . . . . . . . 265 19.6 20-Pin Small Outline Integrated Circuit (SOIC) . . . . . . . . . . . 266 Section 20. Ordering Information 20.1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .267 20.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267 20.3 MC Order Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Table of Contents Technical Data 17 Table of Contents Appendix A. MC68HC08JB8 A.1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .269 A.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270 A.3 MCU Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270 A.4 Memory Map. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270 A.5 Reserved Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273 A.6 Monitor ROM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .273 A.7 Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273 A.7.1 DC Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . .274 A.7.2 Memory Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . 275 A.8 MC68HC08JB8 Order Numbers . . . . . . . . . . . . . . . . . . . . . . . 275 Appendix B. MC68HC08JT8 B.1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .277 B.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278 B.3 MCU Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278 B.4 Memory Map. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278 B.5 Power Supply Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 281 B.6 Reserved Register Bit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 281 B.7 Reserved Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 281 B.8 Monitor ROM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .282 B.9 Universal Serial Bus Module. . . . . . . . . . . . . . . . . . . . . . . . . . 282 B.10 Low-Voltage Inhibit Module . . . . . . . . . . . . . . . . . . . . . . . . . . 282 B.11 Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 282 B.11.1 Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . 282 B.11.2 Functional Operating Range . . . . . . . . . . . . . . . . . . . . . . .283 B.11.3 DC Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . .283 B.11.4 Control Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 284 B.11.5 Memory Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . 284 B.12 MC68HC08JT8 Order Numbers . . . . . . . . . . . . . . . . . . . . . . . 284 Technical Data 18 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Table of Contents Freescale Semiconductor Technical Data — MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 List of Figures Figure Title 1-1 1-2 1-3 1-4 1-5 1-6 MCU Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 44-Pin QFP Pin Assignments . . . . . . . . . . . . . . . . . . . . . . . . . . 32 28-pin SOIC Pin Assignments . . . . . . . . . . . . . . . . . . . . . . . . . 33 20-pin PDIP and SOIC Pin Assignments . . . . . . . . . . . . . . . . . 33 Power Supply Bypassing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Regulator Supply Capacitor Configuration . . . . . . . . . . . . . . . . 35 2-1 2-2 Memory Map. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Control, Status, and Data Registers . . . . . . . . . . . . . . . . . . . . .42 4-1 4-2 4-3 4-4 4-5 FLASH Memory Register Summary . . . . . . . . . . . . . . . . . . . . .54 FLASH Control Register (FLCR) . . . . . . . . . . . . . . . . . . . . . . . 55 FLASH Programming Flowchart . . . . . . . . . . . . . . . . . . . . . . . . 59 FLASH Block Protect Register (FLBPR). . . . . . . . . . . . . . . . . . 60 FLASH Block Protect Start Address . . . . . . . . . . . . . . . . . . . . .60 5-1 Configuration Register (CONFIG). . . . . . . . . . . . . . . . . . . . . . . 66 6-1 6-2 6-3 6-4 6-5 6-6 CPU Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 Accumulator (A) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 Index Register (H:X) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 Stack Pointer (SP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 Program Counter (PC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .73 Condition Code Register (CCR) . . . . . . . . . . . . . . . . . . . . . . . . 74 7-1 Oscillator External Connections . . . . . . . . . . . . . . . . . . . . . . . .90 8-1 8-2 8-3 SIM Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 SIM I/O Register Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . .96 SIM Clock Signals. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .96 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Page List of Figures Technical Data 19 List of Figures Figure Technical Data 20 Title Page 8-4 8-5 8-6 8-7 8-8 8-9 8-10 8-11 8-12 8-13 8-14 8-15 8-16 8-17 8-18 8-19 8-20 External Reset Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .98 Internal Reset Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99 Sources of Internal Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99 POR Recovery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 Interrupt Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105 Interrupt Entry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 Interrupt Recovery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 Interrupt Recognition Example . . . . . . . . . . . . . . . . . . . . . . . . 107 Interrupt Status Register 1 (INT1). . . . . . . . . . . . . . . . . . . . . . 109 Wait Mode Entry Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111 Wait Recovery from Interrupt or Break . . . . . . . . . . . . . . . . . . 111 Wait Recovery from Internal Reset. . . . . . . . . . . . . . . . . . . . . 111 Stop Mode Entry Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112 Stop Mode Recovery from Interrupt or Break . . . . . . . . . . . . . 113 Break Status Register (BSR) . . . . . . . . . . . . . . . . . . . . . . . . . 113 Reset Status Register (RSR) . . . . . . . . . . . . . . . . . . . . . . . . . 115 Break Flag Control Register (BFCR) . . . . . . . . . . . . . . . . . . . 116 9-1 9-2 9-3 9-4 9-5 9-6 9-7 9-8 9-9 9-10 9-11 9-12 9-13 9-14 9-15 9-16 9-17 9-18 USB I/O Register Summary . . . . . . . . . . . . . . . . . . . . . . . . . . 120 USB Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124 Supported Transaction Types Per Endpoint. . . . . . . . . . . . . . 125 Supported USB Packet Types . . . . . . . . . . . . . . . . . . . . . . . . 126 Sync Pattern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126 SOP, Sync Signaling, and Voltage Levels . . . . . . . . . . . . . . . 127 EOP Transaction Voltage Levels . . . . . . . . . . . . . . . . . . . . . . 129 EOP Width Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129 External Low-Speed Device Configuration . . . . . . . . . . . . . . . 132 Regulator Electrical Connections . . . . . . . . . . . . . . . . . . . . . . 133 Receiver Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134 Differential Input Sensitivity Range. . . . . . . . . . . . . . . . . . . . . 135 Data Jitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136 Data Signal Rise and Fall Time . . . . . . . . . . . . . . . . . . . . . . .136 USB Address Register (UADDR) . . . . . . . . . . . . . . . . . . . . . . 138 USB Interrupt Register 0 (UIR0) . . . . . . . . . . . . . . . . . . . . . . . 139 USB Interrupt Register 1 (UIR1) . . . . . . . . . . . . . . . . . . . . . . . 141 USB Interrupt Register 2 (UIR2) . . . . . . . . . . . . . . . . . . . . . . . 144 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 List of Figures Freescale Semiconductor List of Figures Figure Title Page 9-19 9-20 9-21 9-22 9-23 9-24 9-25 9-26 9-27 9-28 9-29 9-30 9-31 9-32 USB Control Register 0 (UCR0) . . . . . . . . . . . . . . . . . . . . . . . 145 USB Control Register 1 (UCR1) . . . . . . . . . . . . . . . . . . . . . . . 146 USB Control Register 2 (UCR2) . . . . . . . . . . . . . . . . . . . . . . . 147 USB Control Register 3 (UCR3) . . . . . . . . . . . . . . . . . . . . . . . 149 USB Control Register 4 (UCR4) . . . . . . . . . . . . . . . . . . . . . . . 151 USB Status Register 0 (USR0). . . . . . . . . . . . . . . . . . . . . . . . 152 USB Status Register 1 (USR1). . . . . . . . . . . . . . . . . . . . . . . . 153 USB Endpoint 0 Data Registers (UE0D0–UE0D7). . . . . . . . . 154 USB Endpoint 1 Data Registers (UE1D0–UE1D7). . . . . . . . . 155 USB Endpoint 2 Data Registers (UE2D0–UE2D7). . . . . . . . . 156 OUT Token Data Flow for Receive Endpoint 0. . . . . . . . . . . . 158 SETUP Token Data Flow for Receive Endpoint 0 . . . . . . . . . 159 IN Token Data Flow for Transmit Endpoint 0 . . . . . . . . . . . . . 160 IN Token Data Flow for Transmit Endpoint 1 . . . . . . . . . . . . . 161 10-1 10-2 10-3 10-4 10-5 10-6 10-7 Monitor Mode Circuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165 Low-Voltage Monitor Mode Entry Flowchart. . . . . . . . . . . . . . 168 Monitor Data Format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170 Sample Monitor Waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . 170 Read Transaction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .170 Break Transaction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .171 Monitor Mode Entry Timing. . . . . . . . . . . . . . . . . . . . . . . . . . .175 11-1 11-2 11-3 11-4 11-5 11-6 11-7 11-8 11-9 TIM Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179 TIM I/O Register Summary . . . . . . . . . . . . . . . . . . . . . . . . . . .180 PWM Period and Pulse Width . . . . . . . . . . . . . . . . . . . . . . . . 184 TIM Status and Control Register (TSC) . . . . . . . . . . . . . . . . . 190 TIM Counter Registers (TCNTH:TCNTL) . . . . . . . . . . . . . . . . 192 TIM Counter Modulo Registers (TMODH:TMODL). . . . . . . . . 193 TIM Channel Status and Control Registers (TSC0:TSC1) . . . 194 CHxMAX Latency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .197 TIM Channel Registers (TCH0H/L:TCH1H/L). . . . . . . . . . . . . 198 12-1 I/O Port Register Summary. . . . . . . . . . . . . . . . . . . . . . . . . . .200 12-2 Port A Data Register (PTA) . . . . . . . . . . . . . . . . . . . . . . . . . . 202 12-3 Data Direction Register A (DDRA) . . . . . . . . . . . . . . . . . . . . . 203 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor List of Figures Technical Data 21 List of Figures 12-4 12-5 12-6 12-7 12-8 12-9 12-10 12-11 12-12 12-13 12-14 12-15 12-16 12-17 Port A I/O Circuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203 Port B Data Register (PTB) . . . . . . . . . . . . . . . . . . . . . . . . . . 204 Data Direction Register B (DDRB) . . . . . . . . . . . . . . . . . . . . . 205 Port B I/O Circuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206 Port C Data Register (PTC) . . . . . . . . . . . . . . . . . . . . . . . . . . 207 Data Direction Register C (DDRC) . . . . . . . . . . . . . . . . . . . . . 208 Port C I/O Circuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209 Port D Data Register (PTD) . . . . . . . . . . . . . . . . . . . . . . . . . . 210 Data Direction Register D (DDRD) . . . . . . . . . . . . . . . . . . . . . 211 Port D I/O Circuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212 Port E Data Register (PTE) . . . . . . . . . . . . . . . . . . . . . . . . . . 213 Data Direction Register E (DDRE) . . . . . . . . . . . . . . . . . . . . . 215 Port E I/O Circuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216 Port Option Control Register (POCR). . . . . . . . . . . . . . . . . . . 217 13-1 13-2 13-3 13-4 IRQ Module Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . 221 IRQ I/O Register Summary. . . . . . . . . . . . . . . . . . . . . . . . . . .221 IRQ Status and Control Register (ISCR) . . . . . . . . . . . . . . . . 224 IRQ Option Control Register (IOCR) . . . . . . . . . . . . . . . . . . . 225 14-1 Keyboard Module Block Diagram . . . . . . . . . . . . . . . . . . . . . . 229 14-2 Keyboard Status and Control Register (KBSCR) . . . . . . . . . . 234 14-3 Keyboard Interrupt Enable Register (KBIER) . . . . . . . . . . . . . 235 15-1 COP Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238 15-2 Configuration Register (CONFIG). . . . . . . . . . . . . . . . . . . . . . 240 15-3 COP Control Register (COPCTL) . . . . . . . . . . . . . . . . . . . . . . 241 16-1 LVI Module Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . .244 16-2 Configuration Register (CONFIG). . . . . . . . . . . . . . . . . . . . . . 244 17-1 17-2 17-3 17-4 17-5 17-6 17-7 Technical Data 22 Break Module Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . 247 Break I/O Register Summary . . . . . . . . . . . . . . . . . . . . . . . . . 247 Break Status and Control Register (BRKSCR). . . . . . . . . . . . 249 Break Address Register High (BRKH) . . . . . . . . . . . . . . . . . . 250 Break Address Register Low (BRKL) . . . . . . . . . . . . . . . . . . . 250 Break Status Register (BSR) . . . . . . . . . . . . . . . . . . . . . . . . . 251 Break Flag Control Register High (BFCR) . . . . . . . . . . . . . . . 252 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 List of Figures Freescale Semiconductor List of Figures Figure Title 19-1 19-2 19-3 19-4 44-Pin QFP (Case #824E) . . . . . . . . . . . . . . . . . . . . . . . . . . . 264 28-Pin SOIC (Case #751F). . . . . . . . . . . . . . . . . . . . . . . . . . .265 20-Pin PDIP (Case #738) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265 20-Pin SOIC (Case #751D) . . . . . . . . . . . . . . . . . . . . . . . . . . 266 A-1 A-2 MC68HC08JB8 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . 271 MC68HC08JB8 Memory Map. . . . . . . . . . . . . . . . . . . . . . . . . 272 B-1 B-2 B-3 MC68HC08JT8 Block Diagram . . . . . . . . . . . . . . . . . . . . . . .279 MC68HC08JT8 Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . 280 Power Supply Bypassing . . . . . . . . . . . . . . . . . . . . . . . . . . . . 281 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Page List of Figures Technical Data 23 List of Figures Technical Data 24 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 List of Figures Freescale Semiconductor Technical Data — MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 List of Tables Table Title 1-1 Summary of Pin Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 2-1 Vector Addresses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50 4-1 4-2 4-3 4-4 4-5 ROM-Resident Routines. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 ROM-Resident Routine Variables. . . . . . . . . . . . . . . . . . . . . . . 62 ERASE Routine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 PROGRAM Routine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 VERIFY Routine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 6-1 6-2 Instruction Set Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 Opcode Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 8-1 8-2 8-3 8-4 SIM Module Signal Name Conventions . . . . . . . . . . . . . . . . . . 95 PIN Bit Set Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98 Registers not Affected by Normal Reset. . . . . . . . . . . . . . . . . 103 Interrupt Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108 9-1 9-2 USB Module Pin Name Conventions . . . . . . . . . . . . . . . . . . . 120 Supported Packet Identifiers. . . . . . . . . . . . . . . . . . . . . . . . . . 127 10-1 10-2 10-3 10-4 10-5 10-6 10-7 10-8 10-9 Mode Entry Requirements and Options . . . . . . . . . . . . . . . . . 166 Monitor Mode Vector Differences . . . . . . . . . . . . . . . . . . . . . . 169 Monitor Baud Rate Selection . . . . . . . . . . . . . . . . . . . . . . . . . 169 READ (Read Memory) Command . . . . . . . . . . . . . . . . . . . . . 172 WRITE (Write Memory) Command. . . . . . . . . . . . . . . . . . . . . 172 IREAD (Indexed Read) Command . . . . . . . . . . . . . . . . . . . . . 173 IWRITE (Indexed Write) Command . . . . . . . . . . . . . . . . . . . . 173 READSP (Read Stack Pointer) Command . . . . . . . . . . . . . . . 174 RUN (Run User Program) Command . . . . . . . . . . . . . . . . . . . 174 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Page List of Tables Technical Data 25 List of Tables 11-1 TIM Pin Name Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . 178 11-2 Prescaler Selection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191 11-3 Mode, Edge, and Level Selection . . . . . . . . . . . . . . . . . . . . . . 196 12-1 12-2 12-3 12-4 12-5 12-6 Port Control Register Bits Summary. . . . . . . . . . . . . . . . . . . .201 Port A Pin Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204 Port B Pin Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206 Port C Pin Functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209 Port D Pin Functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212 Port E Pin Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216 14-1 KBI Pin Name Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . 228 14-2 I/O Register Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .229 20-1 MC Order Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267 A-1 A-2 B-1 B-2 Technical Data 26 Summary of MC68HC08JB8 and MC68HC908JB8 Differences. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270 MC68HC08JB8 Order Numbers . . . . . . . . . . . . . . . . . . . . . . . 275 Summary of MC68HC08JT8 and MC68HC908JB8 Differences. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278 MC68HC08JT8 Order Numbers . . . . . . . . . . . . . . . . . . . . . . . 284 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 List of Tables Freescale Semiconductor Technical Data — MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 Section 1. General Description 1.1 Contents 1.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 1.3 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 1.4 MCU Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 1.5 Pin Assignments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 1.5.1 Power Supply Pins (VDD, VSS) . . . . . . . . . . . . . . . . . . . . . . . 34 1.5.2 Voltage Regulator Out (VREG) . . . . . . . . . . . . . . . . . . . . . . . 34 1.5.3 Oscillator Pins (OSC1 and OSC2) . . . . . . . . . . . . . . . . . . . . 35 1.5.4 External Reset Pin (RST) . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 1.5.5 External Interrupt Pins (IRQ, PTE4/D–) . . . . . . . . . . . . . . . . 35 1.5.6 Port A Input/Output (I/O) Pins (PTA7/KBA7–PTA0/KBA0). . 36 1.5.7 Port B (I/O) Pins (PTB7–PTB0) . . . . . . . . . . . . . . . . . . . . . . 36 1.5.8 Port C I/O Pins (PTC7–PTC0) . . . . . . . . . . . . . . . . . . . . . . . 36 1.5.9 Port D I/O Pins (PTD7–PTD0) . . . . . . . . . . . . . . . . . . . . . . . 36 1.5.10 Port E I/O Pins (PTE4/D–, PTE3/D+, PTE2/TCH1, PTE1/TCH0, PTE0/TCLK). . . . . . . . . . . . . . . . . . . . . . . . 36 1.2 Introduction The MC68HC908JB8 is a member of the low-cost, high-performance M68HC08 Family of 8-bit microcontroller units (MCUs). All MCUs in the family use the enhanced M68HC08 central processor unit (CPU08) and are available with a variety of modules, memory sizes and types, and package types. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor General Description Technical Data 27 General Description 1.3 Features Features of the MC68HC908JB8 include: • High-performance M68HC08 architecture • Fully upward-compatible object code with M6805, M146805, and M68HC05 Families • 3-MHz internal bus frequency • 8,192 bytes of on-chip FLASH memory • 256 bytes of on-chip random-access memory (RAM) • FLASH program memory security1 • On-chip programming firmware for use with host PC computer • Up to 37 general-purpose 3.3V input/output (I/O) pins, including: – 13 or 10 shared-function I/O pins, depending on package – 24, 8, or 2 dedicated I/O pins, depending on package – 8 keyboard interrupts on port A, on all packages – 10mA sink capability for normal LED on 4 pins – 25mA sink capability for infrared LED on 2 pins – 10mA sink capability for PS/2 connection on 2 pins (with USB module disabled) • 16-bit, 2-channel timer interface module (TIM) with selectable input capture, output compare, PWM capability on each channel, and external clock input option (TCLK) • Full Universal Serial Bus Specification 1.1 low-speed functions: – 1.5 Mbps data rate – On-chip 3.3V regulator – Endpoint 0 with 8-byte transmit buffer and 8-byte receive buffer – Endpoint 1 with 8-byte transmit buffer – Endpoint 2 with 8-byte transmit buffer and 8-byte receive buffer 1. No security feature is absolutely secure. However, Freescale’s strategy is to make reading or copying the FLASH difficult for unauthorized users. Technical Data 28 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 General Description Freescale Semiconductor General Description Features • System protection features: – Optional computer operating properly (COP) reset – Optional low-voltage detection with reset – Illegal opcode detection with reset – Illegal address detection with reset • Low-power design (fully static with stop and wait modes) • Master reset pin with internal pullup and power-on reset • External interrupt pin with programmable internal pullup (IRQ) • 44-pin quad flat pack (QFP), 28-pin small outline integrated circuit package (SOIC), 20-pin small outline integrated circuit package (SOIC), and 20-pin plastic dual in-line package (DIP) • Specific features of MC68HC908JB8 in 44-pin are: – Port B is 8 bits: PTB0–PTB7 – Port C is 8 bits: PTC0–PTC7 – Port D is 8 bits: PTD0–PTD7 – Port E is 5 bits: PTE0–PTE4; 2-channel TIM module with TCLK input option • Specific features of MC68HC908JB8 in 28-pin are: – Port B is not available – Port C is only one bit: PTC0 – Port D is only 7 bits: PTD0–PTD6 – Port E is 5 bits: PTE0–PTE4; 2-channel TIM module with TCLK input option • Specific features of MC68HC908JB8 in 20-pin are: – Port B is not available – Port C is only one bit: PTC0 – Port D is only one bit: PTD0/1; internal PTD0 and PTD1 pads are bonded together to a single pin, PTD0/1 – Port E is only 3 bits: PTE1, PTE3, and PTE4; 1-channel TIM module without TCLK input option MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor General Description Technical Data 29 General Description Features of the CPU08 include the following: • Enhanced HC05 programming model • Extensive loop control functions • 16 addressing modes (eight more than the HC05) • 16-bit index register and stack pointer • Memory-to-memory data transfers • Fast 8 × 8 multiply instruction • Fast 16/8 divide instruction • Binary-coded decimal (BCD) instructions • Optimization for controller applications • Efficient C language support 1.4 MCU Block Diagram Figure 1-1 shows the structure of the MC68HC908JB8. Technical Data 30 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 General Description Freescale Semiconductor PTA DDRB PTB PTB7–PTB0 (3) PTC PTC7–PTC0 (3) PTD PTD7–PTD6 (4) PTD5–PTD2 (4) (5) DDRA PTA7/KBA7 (3) : PTA0/KBA0 (3) DDRC CPU REGISTERS ARITHMETIC/LOGIC UNIT (ALU) KEYBOARD INTERRUPT MODULE CONTROL AND STATUS REGISTERS — 64 BYTES TIMER INTERFACE MODULE USER FLASH MEMORY — 8,192 BYTES USER RAM — 256 BYTES BREAK MODULE MONITOR ROM — 976 BYTES OSC1 OSC2 OSCILLATOR LOW VOLTAGE INHIBIT MODULE DDRD USER FLASH VECTORS — 16 BYTES PTD1–PTD0 (4) (6) POWER-ON RESET MODULE PTE4/D– (3) (4) (5) (1), (3) IRQ SYSTEM INTEGRATION MODULE PTE3/D+ (3) (4) (5) COMPUTER OPERATING PROPERLY MODULE IRQ MODULE USB MODULE VDD POWER USB ENDPOINT 0, 1, 2 PTE RST DDRE (1), (2) LS USB TRANSCEIVER General Description MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor INTERNAL BUS M68HC08 CPU PTE2/TCH1 (3) PTE1/TCH0 (3) PTE0/TCLK (3) VSS INTERNAL VOLTAGE REGULATOR 31 Technical Data Figure 1-1. MCU Block Diagram General Description MCU Block Diagram VREG (3.3 V) (1) Pins have 5V logic. (2) Pins have integrated pullup device. (3) Pins have software configurable pullup device. (4) Pins are open-drain when configured as output. (5) Pins have 10mA sink capability. (6) Pins have 25mA sink capability. General Description OSC2 OSC1 VSS PTB3 PTB4 PTB5 PTB6 PTB7 RST PTA0/KBA0 PTA1/KBA1 44 43 42 41 40 39 38 37 36 35 34 1.5 Pin Assignments VREG 1 33 PTA2/KBA2 VDD 2 32 PTA3/KBA3 PTB2 3 31 PTC7 PTB1 4 30 PTC6 PTB0 5 29 PTC5 PTD0 6 28 PTC4 PTD1 7 27 PTE0/TCLK PTD2 17 18 19 20 21 22 IRQ PTD7 PTD6 PTD5 PTA7/KBA7 PTA6/KBA6 16 23 PTC3 11 PTC2 PTA5/KBA5 15 24 14 10 PTC1 PTD4 PTE1/TCH0 PTC0 PTA4/KBA4 13 9 12 PTE2/TCH1 25 PTE4/D– 26 PTE3/D+ 8 PTD3 Figure 1-2. 44-Pin QFP Pin Assignments Technical Data 32 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 General Description Freescale Semiconductor General Description Pin Assignments VSS 1 28 RST OSC1 2 27 PTA0/KBA0 OSC2 3 26 PTA1/KBA1 VREG 4 25 PTA2/KBA2 VDD 5 24 PTA3/KBA3 PTD0 6 23 PTE0/TCLK PTB0 Pins not available on 28-pin package: PTD1 7 22 PTE2/TCH1 PTD2 8 21 PTA4/KBA4 PTB1 PTC1 PTD3 9 20 PTA5/KBA5 PTB2 PTC2 PTD4 10 19 PTA6/KBA6 PTB3 PTC3 PTB4 PTC4 PTB5 PTC5 PTB6 PTC6 PTB7 PTC7 PTE1/TCH0 11 18 PTA7/KBA7 PTE3/D+ 12 17 PTD5 PTE4/D– 13 16 PTD6 PTC0 14 15 IRQ PTD7 Internal pads are unconnected. Figure 1-3. 28-Pin SOIC Pin Assignments PTD0/1 pin: PTD0 and PTD1 internal pads are bonded together to PTD0/1 pin. VSS 1 20 RST OSC1 2 19 PTA0/KBA0 18 PTA1/KBA1 PTB0 PTB1 PTC1 OSC2 3 Pins not available on 20-pin package: PTE0/TCLK VREG 4 17 PTA2/KBA2 VDD 5 16 PTA3/KBA3 PTB2 PTC2 PTD2 PTD0/1 6 15 PTA4/KBA4 PTB3 PTC3 PTD3 PTE1/TCH0 7 14 PTA5/KBA5 PTB4 PTC4 PTD4 PTB5 PTC5 PTD5 PTB6 PTC6 PTD6 PTB7 PTC7 PTD7 PTE3/D+ 8 13 PTA6/KBA6 PTE4/D– 9 12 PTA7/KBA7 10 11 IRQ PTC0 PTE2/TCH1 Internal pads are unconnected. Figure 1-4. 20-Pin PDIP and SOIC Pin Assignments NOTE: In 20-pin package, the PTD0 and PTD1 internal pads are bonded together to PTD0/1 pin. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor General Description Technical Data 33 General Description 1.5.1 Power Supply Pins (VDD, VSS) VDD and VSS are the power supply and ground pins. The MCU operates from a single power supply. Fast signal transitions on MCU pins place high, short-duration current demands on the power supply. To prevent noise problems, take special care to provide power supply bypassing at the MCU as Figure 1-5 shows. Place the bypass capacitors as close to the MCU power pins as possible. Use high-frequency-response ceramic capacitors for CBYPASS. CBULK are optional bulk current bypass capacitors for use in applications that require the port pins to source high current levels. MCU VDD VSS CBYPASS 0.1 µF + CBULK VDD NOTE: Values shown are typical values. Figure 1-5. Power Supply Bypassing 1.5.2 Voltage Regulator Out (VREG) VREG is the 3.3 V output of the on-chip voltage regulator. VREG is used internally for the MCU operation and the USB data driver. It is also used to supply the voltage for the external pullup resistor required on the USB’s D– line. The VREG pin requires an external bulk capacitor 4.7µF or larger and a 0.1 µF ceramic bypass capacitor as Figure 1-6 shows. Place the bypass capacitors as close to the VREG pin as possible. Technical Data 34 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 General Description Freescale Semiconductor General Description Pin Assignments VREG MCU VSS CREGBYPASS 0.1 µF + CREGBULK > 4.7 µF VREG Figure 1-6. Regulator Supply Capacitor Configuration 1.5.3 Oscillator Pins (OSC1 and OSC2) The OSC1 and OSC2 pins are the connections for the on-chip oscillator circuit. 1.5.4 External Reset Pin (RST) A logic zero on the RST pin forces the MCU to a known start-up state. RST is bidirectional, allowing a reset of the entire system. It is driven low when any internal reset source is asserted. The RST pin contains an internal pullup device to VDD. (See Section 8. System Integration Module (SIM).) 1.5.5 External Interrupt Pins (IRQ, PTE4/D–) IRQ is an asynchronous external interrupt pin. IRQ is also the pin to enter monitor mode. The IRQ pin contains a software configurable pullup device to VDD. PTE4/D– can be programmed to trigger the IRQ interrupt. (See Section 13. External Interrupt (IRQ).) MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor General Description Technical Data 35 General Description 1.5.6 Port A Input/Output (I/O) Pins (PTA7/KBA7–PTA0/KBA0) PTA7/KBA7–PTA0/KBA0 are general-purpose bidirectional I/O port pins. (See Section 12. Input/Output Ports (I/O).) Each pin contains a software configurable pullup device to VREG when the pin is configured as an input. (See 12.8 Port Options.) Each pin can also be programmed as an external keyboard interrupt pin. (See Section 14. Keyboard Interrupt Module (KBI).) 1.5.7 Port B (I/O) Pins (PTB7–PTB0) PTB7–PTB0 are general-purpose bidirectional I/O port pins. Each pin contains a software configurable pullup device to VREG when the pin is configured as an input. (See 12.8 Port Options.) 1.5.8 Port C I/O Pins (PTC7–PTC0) PTC7–PTC0 are general-purpose bidirectional I/O port pins. (See Section 12. Input/Output Ports (I/O).) Each pin contains a software configurable pullup device to VREG when the pin is configured as an input. (See 12.8 Port Options.) 1.5.9 Port D I/O Pins (PTD7–PTD0) PTD7–PTD0 are general-purpose bidirectional I/O port pins; open-drain when configured as output. (See Section 12. Input/Output Ports (I/O).) PTD5–PTD2 are software configurable to be 10mA sink pins for direct LED connections. PTD1–PTD0 are software configurable to be 25mA sink pins for direct infrared LED connections. (See 12.8 Port Options.) 1.5.10 Port E I/O Pins (PTE4/D–, PTE3/D+, PTE2/TCH1, PTE1/TCH0, PTE0/TCLK) Port E is a 5-bit special function port that shares two of its pins with the USB module and three of its pins with the timer interface module. Each PTE2–PTE0 pin contains a software configurable pullup device to VREG when the pin is configured as an input or output. Technical Data 36 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 General Description Freescale Semiconductor General Description Pin Assignments When the USB module is disabled, the PTE4 and PTE3 pins are general-purpose bidirectional I/O port pins with 10mA sink capability. Each pin is open-drain when configured as an output; and each pin contains a software configurable 5kΩ pullup to VDD when configured as an input. The PTE4 pin can also be enabled to trigger the IRQ interrupt. When the USB module is enabled, the PTE4/D– and PTE3/D+ pins become the USB module D– and D+ pins. The D– pin contains a software configurable 1.5kΩ pullup to VREG. (See Section 11. Timer Interface Module (TIM), Section 9. Universal Serial Bus Module (USB) and Section 12. Input/Output Ports (I/O).) Summary of the pin functions are provided in Table 1-1. Table 1-1. Summary of Pin Functions PIN NAME PIN DESCRIPTION IN/OUT VOLTAGE LEVEL IN 4.0 to 5.5V VDD Power supply. VSS Power supply ground. OUT 0V VREG Regulated 3.3V output from MCU. OUT VREG (3.3V) RST Reset input; active low. With internal pullup to VDD and schmitt trigger input. IN/OUT VDD External IRQ pin; with programmable internal pullup to VDD and schmitt trigger input. IN VDD Used for mode entry selection. IN VREG to VDD +VHI OSC1 Crystal oscillator input. IN VREG OSC2 Crystal oscillator output; inverting of OSC1 signal. OUT VREG IN/OUT VREG Pins as keyboard interrupts, KBA0–KBA7. IN VREG Each pin has programmable internal pullup to VREG when configured as input. IN VREG IN/OUT VREG IN VREG IRQ 8-bit general-purpose I/O port. PTA0/KBA0 : PTA7/KBA7 8-bit general-purpose I/O port. PTB0–PTB7 Each pin has programmable internal pullup to VREG when configured as input. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor General Description Technical Data 37 General Description Table 1-1. Summary of Pin Functions PIN NAME PIN DESCRIPTION IN/OUT VOLTAGE LEVEL IN/OUT VREG IN VREG 8-bit general-purpose I/O port; open-drain when configured as output. IN OUT VREG VREG or VDD PTD0–PTD1 have configurable 25mA sink for infrared LED. OUT VREG or VDD PTD2–PTD5 have configurable 10mA sink for LED. OUT VREG or VDD PTE0–PTE2 are general-purpose I/O pins. IN/OUT VREG PTE0–PTE2 have programmable internal pullup to VREG when configured as input or output. IN/OUT VREG PTE0 as TCLK of timer interface module. IN VREG PTE1 as TCH0 of timer interface module. IN/OUT VREG PTE2 as TCH1 of timer interface module. IN/OUT VREG IN OUT VDD VREG or VDD IN VDD 8-bit general-purpose I/O port. PTC0–PTC7 PTD0–PTD7 PTE0/TCLK PTE1/TCH0 Each pin has programmable internal pullup to VREG when configured as input. PTE2/TCH1 PTE3–PTE4 are general-purpose I/O pins; open-drain when configured as output. PTE3/D+ PTE3–PTE4 have programmable internal pullup to VDD when configured as input. PTE4/D– PTE3 as D+ of USB module. IN/OUT VREG PTE4 as D– of USB module. IN/OUT VREG IN VDD PTE4 as additional IRQ interrupt. Technical Data 38 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 General Description Freescale Semiconductor Technical Data — MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 Section 2. Memory Map 2.1 Contents 2.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 2.3 I/O Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 2.4 Monitor ROM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41 2.2 Introduction The CPU08 can address 64 Kbytes of memory space. The memory map, shown in Figure 2-1, includes: • 8,192 bytes of user FLASH memory • 256 bytes of RAM • 16 bytes of user-defined vectors • 976 bytes of monitor ROM MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Memory Map Technical Data 39 Memory Map $0000 ↓ $003F I/O Registers 64 Bytes $0040 ↓ $013F RAM 256 Bytes $0140 ↓ $DBFF Unimplemented 56,000 Bytes $DC00 ↓ $FBFF FLASH 8,192 Bytes $FC00 ↓ $FDFF Monitor ROM 1 512 Bytes $FE00 Break Status Register (BSR) $FE01 Reset Status Register (RSR) $FE02 Reserved $FE03 Break Flag Control Register (BFCR) $FE04 Interrupt Status Register 1 (INT1) $FE05 Reserved $FE06 Reserved $FE07 Reserved $FE08 FLASH Control Register (FLCR) $FE09 FLASH Block Protect Register (FLBPR) $FE0A Reserved $FE0B Reserved $FE0C Break Address High Register (BRKH) $FE0D Break Address Low Register (BRKL) $FE0E Break Status and Control Register (BRKSCR) $FE0F Reserved $FE10 ↓ $FFDF Monitor ROM 2 464 Bytes $FFE0 ↓ $FFEF Reserved 16 Bytes $FFF0 ↓ $FFFF FLASH Vectors 16 Bytes Figure 2-1. Memory Map Technical Data 40 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Memory Map Freescale Semiconductor Memory Map I/O Section 2.3 I/O Section Addresses $0000–$003F, shown in Figure 2-2, contain most of the control, status, and data registers. Additional I/O registers have these addresses: • $FE00; break status register, BSR • $FE01; reset status register, RSR • $FE02; reserved • $FE03; break flag control register, BFCR • $FE04; interrupt status register 1, INT1 • $FE05; reserved • $FE06; reserved • $FE07; reserved • $FE08; FLASH control register, FLCR • $FE09; FLASH block protect register, FLBPR • $FE0A; reserved • $FE0B; reserved • $FE0C; break Address Register High, BRKH • $FE0D; break Address Register Low, BRKL • $FE0E; break status and control register, BRKSCR • $FFFF; COP control register, COPCTL 2.4 Monitor ROM The 512 bytes at addresses $FC00–$FDFF and 464 bytes at addresses $FE10–$FFDF are reserved ROM addresses that contain the instructions for the monitor functions. (See Section 10. Monitor ROM (MON).) MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Memory Map Technical Data 41 Memory Map Addr. Register Name $0000 Read: Port A Data Register Write: (PTA) Reset: $0001 $0002 $0003 Read: Port B Data Register Write: (PTB) Reset: Read: Port C Data Register Write: (PTC) Reset: Read: Port D Data Register Write: (PTD) Reset: Bit 7 6 5 4 3 2 1 Bit 0 PTA7 PTA6 PTA5 PTA4 PTA3 PTA2 PTA1 PTA0 PTB2 PTB1 PTB0 PTC2 PTC1 PTC0 PTD2 PTD1 PTD0 Unaffected by reset PTB7 PTB6 PTB5 PTB4 PTB3 Unaffected by reset PTC7 PTC6 PTC5 PTC4 PTC3 Unaffected by reset PTD7 PTD6 PTD5 PTD4 PTD3 Unaffected by reset Read: DDRA7 Data Direction Register A $0004 Write: (DDRA) Reset: 0* DDRA6 DDRA5 DDRA4 DDRA3 DDRA2 DDRA1 DDRA0 0 0 0 0 0 0 0 DDRB6 DDRB5 DDRB4 DDRB3 DDRB2 DDRB1 DDRB0 0 0 0 0 0 0 0 DDRC6 DDRC5 DDRC4 DDRC3 DDRC2 DDRC1 DDRC0 0 0 0 0 0 0 0 DDRD6 DDRD5 DDRD4 DDRD3 DDRD2 DDRD1 DDRD0 0 0 0 0 0 0 0 0 0 PTE4 PTE3 PTE2 PTE1 PTE0 * DDRA7 bit is reset by POR or LVI reset only. Read: DDRB7 Data Direction Register B $0005 Write: (DDRB) Reset: 0 Read: DDRC7 Data Direction Register C $0006 Write: (DDRC) Reset: 0 Read: DDRD7 Data Direction Register D $0007 Write: (DDRD) Reset: 0 Read: Port E Data Register Write: (PTE) Reset: 0 Read: Data Direction Register E $0009 Write: (DDRE) Reset: 0 0 0 0 0 $0008 Unaffected by reset DDRE4 DDRE3 DDRE2 DDRE1 DDRE0 0 0 0 0 0 0 = Unimplemented R = Reserved U = Unaffected by reset Figure 2-2. Control, Status, and Data Registers (Sheet 1 of 8) Technical Data 42 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Memory Map Freescale Semiconductor Memory Map Monitor ROM Addr. $000A Register Name Bit 7 Read: TIM Status and Control Register Write: (TSC) Reset: 6 5 TOIE TSTOP 0 0 1 0 TOF 0 4 3 2 1 Bit 0 0 0 PS2 PS1 PS0 0 0 0 0 TRST Read: $000B Unimplemented Write: Bit15 Bit14 Bit13 Bit12 Bit11 Bit10 Bit9 Bit8 $000C Read: TIM Counter Register High Write: (TCNTH) Reset: 0 0 0 0 0 0 0 0 Read: TIM Counter Register Low Write: (TCNTL) Reset: Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 0 0 0 0 0 0 0 0 Bit15 Bit14 Bit13 Bit12 Bit11 Bit10 Bit9 Bit8 1 1 1 1 1 1 1 1 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 1 1 1 1 1 1 1 1 CH0IE MS0B MS0A ELS0B ELS0A TOV0 CH0MAX 0 0 0 0 0 0 0 0 Bit15 Bit14 Bit13 Bit12 Bit11 Bit10 Bit9 Bit8 Bit2 Bit1 Bit0 $000D $000E $000F Read: TIM Counter Modulo Register High Write: (TMODH) Reset: Read: TIM Counter Modulo Register Low Write: (TMODL) Reset: Read: TIM Channel 0 Status and $0010 Control Register Write: (TSC0) Reset: $0011 $0012 Read: TIM Channel 0 Register High Write: (TCH0H) Reset: Read: TIM Channel 0 Register Low Write: (TCH0L) Reset: Read: TIM Channel 1 Status and $0013 Control Register Write: (TSC1) Reset: CH0F 0 Indeterminate after reset Bit7 Bit6 Bit5 Bit4 Bit3 Indeterminate after reset CH1F 0 0 CH1IE 0 MS1A ELS1B ELS1A TOV1 CH1MAX 0 0 0 0 0 0 = Unimplemented R 0 = Reserved U = Unaffected by reset Figure 2-2. Control, Status, and Data Registers (Sheet 2 of 8) MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Memory Map Technical Data 43 Memory Map Addr. Register Name Read: TIM Channel 1 Register High Write: (TCH1H) Reset: $0014 $0017 $0018 $0019 $001A 6 5 4 3 2 1 Bit 0 Bit15 Bit14 Bit13 Bit12 Bit11 Bit10 Bit9 Bit8 Bit2 Bit1 Bit0 IMASKK MODEK Indeterminate after reset Read: TIM Channel 1 Register Low Write: (TCH1L) Reset: $0015 $0016 Bit 7 Bit7 0 Read: USB Control Register 3 Write: (UCR3) Reset: Bit4 Bit3 0 0 0 KEYF 0 ACKK 0 0 0 0 0 0 0 0 KBIE7 KBIE6 KBIE5 KBIE4 KBIE3 KBIE2 KBIE1 KBIE0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 RSTFR TXD2FR RXD2FR 0 0 0 0 0 0 0 T2SEQ STALL2 TX2E RX2E TP2SIZ3 TP2SIZ2 TP2SIZ1 TP2SIZ0 0 0 0 0 0 0 0 0 TX1ST 0 OSTALL0 ISTALL0 Read: 0 USB Interrupt Register 2 Write: EOPFR (UIR2) Reset: 0 Read: USB Control Register 2 Write: (UCR2) Reset: Bit5 Indeterminate after reset Read: Keyboard Status and Control Register Write: (KBSCR) Reset: Read: Keyboard Interrupt Enable Register Write: (KBIER) Reset: Bit6 TX1STR TDX1FR RESUMFR TXD0FR 0 0 0 0 0 0 Read: USB Control Register 4 Write: (UCR4) Reset: 0 0 0 0 0 0 0 0 0 Read: IRQ Option Control Register Write: (IOCR) Reset: 0 0 0 0 0 0 RXD0FR PULLEN ENABLE2 ENABLE1 0* 0 0 FUSBO FDP FDM 0 0 0 0 0 0 PTE4IF PTE4IE IRQPD 0 0 0 0 0 PTE4P PTE3P PCP PBP PAP 0 0 0 0 0 0 = Unimplemented R * PULLEN bit is reset by POR or LVI reset only. $001B $001C $001D Read: Port Option Control PTE20P Register Write: (POCR) Reset: 0 PTDLDD PTDILDD 0 = Reserved U = Unaffected by reset Figure 2-2. Control, Status, and Data Registers (Sheet 3 of 8) Technical Data 44 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Memory Map Freescale Semiconductor Memory Map Monitor ROM Addr. $001E $001F Register Name Bit 7 6 5 4 3 2 Read: IRQ Status and Control Register Write: (ISCR) Reset: 0 0 0 0 IRQF 0 0 0 Read: Configuration Register Write: (CONFIG)† Reset: 0 0 0 0 ACK 1 Bit 0 IMASK MODE 0 0 0 0 0 0 URSTD LVID SSREC COPRS STOP COPD 0 0 0 0 0 0 † One-time writable register after each reset. URSTD and LVID bits are reset by POR or LVI reset only. $0020 $0021 $0022 $0023 $0024 $0025 $0026 $0027 Read: UE0R07 USB Endpoint 0 Data Register 0 Write: UE0T07 (UE0D0) Reset: UE0R06 UE0R05 UE0R04 UE0R03 UE0R02 UE0R01 UE0R00 UE0T06 UE0T05 UE0T04 UE0T03 UE0T02 UE0T01 UE0T00 Read: UE0R17 USB Endpoint 0 Data Register 1 Write: UE0T17 (UE0D1) Reset: UE0R16 UE0R15 UE0R14 UE0R13 UE0R12 UE0R11 UE0R10 UE0T16 UE0T15 UE0T14 UE0T13 UE0T12 UE0T11 UE0T10 Read: UE0R27 USB Endpoint 0 Data Register 2 Write: UE0T27 (UE0D2) Reset: UE0R26 UE0R25 UE0R24 UE0R23 UE0R22 UE0R21 UE0R20 UE0T26 UE0T25 UE0T24 UE0T23 UE0T22 UE0T21 UE0T20 Read: UE0R37 USB Endpoint 0 Data Register 3 Write: UE0T37 (UE0D3) Reset: UE0R36 UE0R35 UE0R34 UE0R33 UE0R32 UE0R31 UE0R30 UE0T36 UE0T35 UE0T34 UE0T33 UE0T32 UE0T31 UE0T30 Read: UE0R47 USB Endpoint 0 Data Register 4 Write: UE0T47 (UE0D4) Reset: UE0R46 UE0R45 UE0R44 UE0R43 UE0R42 UE0R41 UE0R40 UE0T46 UE0T45 UE0T44 UE0T43 UE0T42 UE0T41 UE0T40 Read: UE0R57 USB Endpoint 0 Data Register 5 Write: UE0T57 (UE0D5) Reset: UE0R56 UE0R55 UE0R54 UE0R53 UE0R52 UE0R51 UE0R50 UE0T56 UE0T55 UE0T54 UE0T53 UE0T52 UE0T51 UE0T50 Read: UE0R67 USB Endpoint 0 Data Register 6 Write: UE0T67 (UE0D6) Reset: UE0R66 UE0R65 UE0R64 UE0R63 UE0R62 UE0R61 UE0R60 UE0T66 UE0T65 UE0T64 UE0T63 UE0T62 UE0T61 UE0T60 Read: UE0R77 USB Endpoint 0 Data Register 7 Write: UE0T77 (UE0D7) Reset: UE0R76 UE0R75 UE0R74 UE0R73 UE0R72 UE0R71 UE0R70 UE0T76 UE0T75 UE0T74 UE0T73 UE0T72 UE0T71 UE0T70 Unaffected by reset Unaffected by reset Unaffected by reset Unaffected by reset Unaffected by reset Unaffected by reset Unaffected by reset Unaffected by reset = Unimplemented R = Reserved U = Unaffected by reset Figure 2-2. Control, Status, and Data Registers (Sheet 4 of 8) MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Memory Map Technical Data 45 Memory Map Addr. Register Name $0028 $0029 $002A $002B $002C $002D $002E $002F $0030 $0031 Bit 7 6 5 4 3 2 1 Bit 0 Read: USB Endpoint 1 Data Register 0 Write: UE1T07 (UE1D0) Reset: UE1T06 UE1T05 UE1T04 UE1T03 UE1T02 UE1T01 UE1T00 Read: USB Endpoint 1 Data Register 1 Write: UE1T17 (UE1D1) Reset: UE1T16 UE1T12 UE1T11 UE1T10 Read: USB Endpoint 1 Data Register 2 Write: UE1T27 (UE1D2) Reset: UE1T26 UE1T22 UE1T21 UE1T20 Read: USB Endpoint 1 Data Register 3 Write: UE1T37 (UE1D3) Reset: UE1T36 UE1T32 UE1T31 UE1T30 Read: USB Endpoint 1 Data Register 4 Write: UE1T47 (UE1D4) Reset: UE1T46 UE1T42 UE1T41 UE1T40 Read: USB Endpoint 1 Data Register 5 Write: UE1T57 (UE1D5) Reset: UE1T56 UE1T52 UE1T51 UE1T50 Read: USB Endpoint 1 Data Register 6 Write: UE1T67 (UE1D6) Reset: UE1T66 UE1T62 UE1T61 UE1T60 Read: USB Endpoint 1 Data Register 7 Write: UE1T77 (UE1D7) Reset: UE1T76 UE1T72 UE1T71 UE1T70 Unaffected by reset UE1T15 UE1T14 UE1T13 Unaffected by reset UE1T25 UE1T24 UE1T23 Unaffected by reset UE1T35 UE1T34 UE1T33 Unaffected by reset UE1T45 UE1T44 UE1T43 Unaffected by reset UE1T55 UE1T54 UE1T53 Unaffected by reset UE1T65 UE1T64 UE1T63 Unaffected by reset UE1T75 UE1T74 UE1T73 Unaffected by reset Read: UE2R07 USB Endpoint 2 Data Register 0 Write: UE2T07 (UE2D0) Reset: UE2R06 UE2R05 UE2R04 UE2R03 UE2R02 UE2R01 UE2R00 UE2T06 UE2T05 UE2T04 UE2T03 UE2T02 UE2T01 UE2T00 Read: UE2R17 USB Endpoint 2 Data Register 1 Write: UE2T17 (UE2D1) Reset: UE2R16 UE2R15 UE2R14 UE2R13 UE2R12 UE2R11 UE2R10 UE2T16 UE2T15 UE2T14 UE2T13 UE2T12 UE2T11 UE2T10 Unaffected by reset Unaffected by reset = Unimplemented R = Reserved U = Unaffected by reset Figure 2-2. Control, Status, and Data Registers (Sheet 5 of 8) Technical Data 46 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Memory Map Freescale Semiconductor Memory Map Monitor ROM Addr. Register Name $0032 $0033 $0034 $0035 $0036 $0037 $0038 Bit 7 6 5 4 3 2 1 Bit 0 Read: UE2R27 USB Endpoint 2 Data Register 2 Write: UE2T27 (UE2D2) Reset: UE2R26 UE2R25 UE2R24 UE2R23 UE2R22 UE2R21 UE2R20 UE2T26 UE2T25 UE2T24 UE2T23 UE2T22 UE2T21 UE2T20 Read: UE2R37 USB Endpoint 2 Data Register 3 Write: UE2T37 (UE2D3) Reset: UE2R36 UE2R35 UE2R34 UE2R33 UE2R32 UE2R31 UE2R30 UE2T36 UE2T35 UE2T34 UE2T33 UE2T32 UE2T31 UE2T30 Read: UE2R47 USB Endpoint 2 Data Register 4 Write: UE2T47 (UE2D4) Reset: UE2R46 UE2R45 UE2R44 UE2R43 UE2R42 UE2R41 UE2R40 UE2T46 UE2T45 UE2T44 UE2T43 UE2T42 UE2T41 UE2T40 Read: UE2R57 USB Endpoint 2 Data Register 5 Write: UE2T57 (UE2D5) Reset: UE2R56 UE2R55 UE2R54 UE2R53 UE2R52 UE2R51 UE2R50 UE2T56 UE2T55 UE2T54 UE2T53 UE2T52 UE2T51 UE2T50 Read: UE2R67 USB Endpoint 2 Data Register 6 Write: UE2T67 (UE2D6) Reset: UE2R66 UE2R65 UE2R64 UE2R63 UE2R62 UE2R61 UE2R60 UE2T66 UE2T65 UE2T64 UE2T63 UE2T62 UE2T61 UE2T60 Read: UE2R77 USB Endpoint 2 Data Register 7 Write: UE2T77 (UE2D7) Reset: UE2R76 UE2R75 UE2R74 UE2R73 UE2R72 UE2R71 UE2R70 UE2T76 UE2T75 UE2T74 UE2T73 UE2T72 UE2T71 UE2T70 Read: USBEN USB Address Register Write: (UADDR) Reset: 0* Unaffected by reset Unaffected by reset Unaffected by reset Unaffected by reset Unaffected by reset Unaffected by reset UADD6 UADD5 UADD4 UADD3 UADD2 UADD1 UADD0 0 0 0 0 0 0 0 EOPIE SUSPND TXD2IE RXD2IE TXD1IE TXD0IE RXD0IE 0 0 0 0 0 0 0 0 EOPF RSTF TXD2F RXD2F TXD1F RESUMF TXD0F RXD0F 0 0 0 0 0 0 0 0 TX0E RX0E TP0SIZ3 TP0SIZ2 TP0SIZ1 TP0SIZ0 0 0 0 0 0 0 = Unimplemented R * USBEN bit is reset by POR or LVI reset only. $0039 $003A $003B Read: USB Interrupt Register 0 Write: (UIR0) Reset: Read: USB Interrupt Register 1 Write: (UIR1) Reset: Read: USB Control Register 0 Write: (UCR0) Reset: T0SEQ 0 0 0 = Reserved 0 U = Unaffected by reset Figure 2-2. Control, Status, and Data Registers (Sheet 6 of 8) MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Memory Map Technical Data 47 Memory Map Addr. $003C $003D $003E Register Name Bit 7 6 5 T1SEQ STALL1 TX1E 0 0 0 0 Read: R0SEQ USB Status Register 0 Write: (USR0) Reset: SETUP 0 0 Read: R2SEQ USB Status Register 1 Write: (USR1) Reset: U TXACK TXNAK TXSTL 0 0 R R Read: USB Control Register 1 Write: (UCR1) Reset: 4 3 2 1 Bit 0 TP1SIZ2 TP1SIZ1 TP1SIZ0 0 0 0 0 RP0SIZ3 RP0SIZ2 RP0SIZ1 RP0SIZ0 RP2SIZ3 RP2SIZ2 RP2SIZ1 RP2SIZ0 0 U U U U R R R FRESUM TP1SIZ3 Unaffected by reset Read: $003F Unimplemented Write: $FE00 Read: Break Status Register Write: (BSR) Reset: R SBSW See note R 0 Note: Writing a logic 0 clears SBSW. $FE01 Read: Reset Status Register Write: (RSR) POR: Read: $FE02 Reserved Write: $FE03 Read: Break Flag Control Register Write: (BFCR) Reset: Read: Interrupt Status Register 1 $FE04 Write: (INT1) Reset: Read: $FE05 Reserved Write: POR PIN COP ILOP ILAD USB LVI 0 1 0 0 0 0 0 0 0 R R R R R R R R BCFE R R R R R R R IF6 IF5 IF4 IF3 IF2 IF1 0 0 R R R R R R R R 0 0 0 0 0 0 0 0 R R R R R R R R = Unimplemented R 0 = Reserved U = Unaffected by reset Figure 2-2. Control, Status, and Data Registers (Sheet 7 of 8) Technical Data 48 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Memory Map Freescale Semiconductor Memory Map Monitor ROM Addr. Register Name Read: $FE06 Reserved Write: Read: $FE07 Reserved Write: $FE08 Read: FLASH Control Register Write: (FLCR) Reset: $FE09 Read: FLASH Block Protect Register Write: (FLBPR) Reset: Read: $FE0A Reserved Write: Read: $FE0B Reserved Write: $FE0C Read: Break Address High Register Write: (BRKH) Reset: $FE0D Read: Break Address low Register Write: (BRKL) Reset: Read: Break Status and Control $FE0E Register Write: (BRKSCR) Reset: $FFFF Read: COP Control Register Write: (COPCTL) Reset: Bit 7 6 5 4 3 2 1 Bit 0 R R R R R R R R R R R R R R R R 0 0 0 0 HVEN MASS ERASE PGM 0 0 0 0 0 0 0 0 BPR7 BPR6 BPR5 BPR4 BPR3 BPR2 BPR1 BPR0 0 0 0 0 0 0 0 0 R R R R R R R R R R R R R R R R Bit15 Bit14 Bit13 Bit12 Bit11 Bit10 Bit9 Bit8 0 0 0 0 0 0 0 0 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 0 0 0 0 0 0 0 0 BRKE BRKA 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Low byte of reset vector Writing clears COP counter (any value) Unaffected by reset = Unimplemented R = Reserved U = Unaffected by reset Figure 2-2. Control, Status, and Data Registers (Sheet 8 of 8) MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Memory Map Technical Data 49 Memory Map Table 2-1 is a list of vector locations. Table 2-1. Vector Addresses Vector Priority INT Flag Lowest Address Vector $FFF0 Keyboard Vector (High) $FFF1 Keyboard Vector (Low) $FFF2 TIM Overflow Vector (High) $FFF3 TIM Overflow Vector (Low) $FFF4 TIM Channel 1 Vector (High) $FFF5 TIM Channel 1 Vector (Low) $FFF6 TIM Channel 0 Vector (High) $FFF7 TIM Channel 0 Vector (Low) $FFF8 IRQ Vector (High) $FFF9 IRQ Vector (Low) $FFFA USB Vector (High) $FFFB USB Vector (Low) $FFFC SWI Vector (High) $FFFD SWI Vector (Low) $FFFE Reset Vector (High) $FFFF Reset Vector (Low) IF6 IF5 IF4 IF3 IF1 IF2 — — Highest Technical Data 50 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Memory Map Freescale Semiconductor Technical Data — MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 Section 3. Random-Access Memory (RAM) 3.1 Contents 3.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 3.3 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51 3.2 Introduction This section describes the 256 bytes of RAM. 3.3 Functional Description Addresses $0040–$013F are RAM locations. The location of the stack RAM is programmable. The 16-bit stack pointer allows the stack to be anywhere in the 64-Kbyte memory space. NOTE: For correct operation, the stack pointer must point only to RAM locations. Within page zero are 192 bytes of RAM. Because the location of the stack RAM is programmable, all page zero RAM locations can be used for I/O control and user data or code. When the stack pointer is moved from its reset location at $00FF, direct addressing mode instructions can access efficiently all page zero RAM locations. Page zero RAM, therefore, provides ideal locations for frequently accessed global variables. Before processing an interrupt, the CPU uses five bytes of the stack to save the contents of the CPU registers. NOTE: For M6805 Family compatibility, the H register is not stacked. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Random-Access Memory (RAM) Technical Data 51 Random-Access Memory (RAM) During a subroutine call, the CPU uses two bytes of the stack to store the return address. The stack pointer decrements during pushes and increments during pulls. NOTE: Technical Data 52 Be careful when using nested subroutines. The CPU may overwrite data in the RAM during a subroutine or during the interrupt stacking operation. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Random-Access Memory (RAM) Freescale Semiconductor Technical Data — MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 Section 4. FLASH Memory 4.1 Contents 4.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 4.3 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54 4.4 FLASH Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 4.5 FLASH Block Erase Operation . . . . . . . . . . . . . . . . . . . . . . . . . 56 4.6 FLASH Mass Erase Operation . . . . . . . . . . . . . . . . . . . . . . . . . 57 4.7 FLASH Program Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . .58 4.8 FLASH Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60 4.8.1 FLASH Block Protect Register . . . . . . . . . . . . . . . . . . . . . . . 60 4.9 ROM-Resident Routines. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 4.9.1 Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 4.9.2 ERASE Routine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 4.9.3 PROGRAM Routine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 4.9.4 VERIFY Routine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 4.2 Introduction This section describes the operation of the embedded FLASH memory. This memory can be read, programmed, and erased from a single external supply. The program and erase operations are enabled through the use of an internal charge pump. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor FLASH Memory Technical Data 53 FLASH Memory Addr. $FE08 $FE09 Register Name Bit 7 6 5 4 FLASH Control Register Read: (FLCR) Write: 0 0 0 0 Reset: 0 0 0 BPR7 BPR6 0 0 FLASH Block Protect Read: Register (FLBPR) Write: Reset: 3 2 1 Bit 0 HVEN MASS ERASE PGM 0 0 0 0 0 BPR5 BPR4 BPR3 BPR2 BPR1 BPR0 0 0 0 0 0 0 Figure 4-1. FLASH Memory Register Summary 4.3 Functional Description The FLASH memory consists of an array of 8,192 bytes for user memory plus a small block of 16 bytes for user interrupt vectors. An erased bit reads as logic 1 and a programmed bit reads as a logic 0. The FLASH memory is block erasable. The minimum erase block size is 512 bytes. Program and erase operation operations are facilitated through control bits in FLASH control register (FLCR).The address ranges for the FLASH memory are shown as follows: • $DC00–$FBFF (user memory; 8,192 bytes) • $FFF0–$FFFF (user interrupt vectors; 16 bytes) Programming tools are available from Freescale. Contact your local Freescale representative for more information. NOTE: A security feature prevents viewing of the FLASH contents.1 1. No security feature is absolutely secure. However, Freescale’s strategy is to make reading or copying the FLASH difficult for unauthorized users. Technical Data 54 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 FLASH Memory Freescale Semiconductor FLASH Memory FLASH Control Register 4.4 FLASH Control Register The FLASH control register (FLCR) controls FLASH program and erase operations. Address: Read: $FE08 Bit 7 6 5 4 0 0 0 0 3 2 1 Bit 0 HVEN MASS ERASE PGM 0 0 0 0 Write: Reset: 0 0 0 0 Figure 4-2. FLASH Control Register (FLCR) HVEN — High Voltage Enable Bit This read/write bit enables high voltage from the charge pump to the memory for either program or erase operation. It can only be set if either PGM or ERASE is high and the sequence for erase or program/verify is followed. 1 = High voltage enabled to array and charge pump on 0 = High voltage disabled to array and charge pump off MASS — Mass Erase Control Bit This read/write bit configures the memory for mass erase operation or block erase operation when the ERASE bit is set. 1 = Mass Erase operation selected 0 = Block Erase operation selected ERASE — Erase Control Bit This read/write bit configures the memory for erase operation. This bit and the PGM bit should not be set to 1 at the same time. 1 = Erase operation selected 0 = Erase operation not selected PGM — Program Control Bit This read/write bit configures the memory for program operation. This bit and the ERASE bit should not be set to 1 at the same time. 1 = Program operation selected 0 = Program operation not selected MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor FLASH Memory Technical Data 55 FLASH Memory 4.5 FLASH Block Erase Operation Use the following procedure to erase a block of FLASH memory. A block consists of 512 consecutive bytes starting from addresses $X000, $X200, $X400, $X600, $X800, $XA00, $XC00 or $XE00. Any block within the 8,192 bytes user memory area ($DC00–$FBFF) can be erased alone. NOTE: The 16-byte user vectors, $FFF0–$FFFF, cannot be erased by the block erase operation because of security reasons. Mass erase is required to erase this block. 1. Set the ERASE bit and clear the MASS bit in the FLASH control register. 2. Write any data to any FLASH address within the address range of the block to be erased. 3. Wait for a time, tnvs (5 µs). 4. Set the HVEN bit. 5. Wait for a time terase (2 ms). 6. Clear the ERASE bit. 7. Wait for a time, tnvh (5 µs). 8. Clear the HVEN bit. 9. After time, trcv (1 µs), the memory can be accessed in read mode again. NOTE: Technical Data 56 Programming and erasing of FLASH locations cannot be performed by code being executed from the FLASH memory. While these operations must be performed in the order as shown, but other unrelated operations may occur between the steps. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 FLASH Memory Freescale Semiconductor FLASH Memory FLASH Mass Erase Operation 4.6 FLASH Mass Erase Operation Use the following procedure to erase the entire FLASH memory: 1. Set both the ERASE bit and the MASS bit in the FLASH control register. 2. Write any data to any FLASH address within the address range $FFE0–$FFFF. 3. Wait for a time, tnvs (5 µs). 4. Set the HVEN bit. 5. Wait for a time tme (2 ms). 6. Clear the ERASE bit. 7. Wait for a time, tnvh1 (100 µs). 8. Clear the HVEN bit. 9. After time, trcv (1 µs), the memory can be accessed in read mode again. NOTE: Programming and erasing of FLASH locations cannot be performed by code being executed from the FLASH memory. While these operations must be performed in the order as shown, but other unrelated operations may occur between the steps. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor FLASH Memory Technical Data 57 FLASH Memory 4.7 FLASH Program Operation Programming of the FLASH memory is done on a row basis. A row consists of 64 consecutive bytes starting from addresses $XX00, $XX40, $XX80 or $XXC0. The procedure for programming a row of the FLASH memory is outlined below: 1. Set the PGM bit. This configures the memory for program operation and enables the latching of address and data for programming. 2. Write any data to any FLASH address within the address range of the row to be programmed. 3. Wait for a time, tnvs (5 µs). 4. Set the HVEN bit. 5. Wait for a time, tpgs (10 µs). 6. Write data to the byte being programmed. 7. Wait for time, tPROG (20 µs). 8. Repeat step 6 and 7 until all the bytes within the row are programmed. 9. Clear the PGM bit. 10. Wait for time, tnvh (5 µs). 11. Clear the HVEN bit. 12. After time, trcv (1 µs), the memory can be accessed in read mode again. This program sequence is repeated throughout the memory until all data is programmed. NOTE: Programming and erasing of FLASH locations cannot be performed by code being executed from the FLASH memory. While these operations must be performed in the order shown, other unrelated operations may occur between the steps. Do not exceed tPROG maximum (see 18.13 Memory Characteristics). Figure 4-3 shows a flowchart representation for programming the FLASH memory. Technical Data 58 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 FLASH Memory Freescale Semiconductor FLASH Memory FLASH Program Operation 1 Algorithm for programming a row (64 bytes) of FLASH memory Set PGM bit 2 Write any data to any FLASH address within the row address range desired 3 Wait for a time, tnvs 4 Set HVEN bit 5 Wait for a time, tpgs 6 Write data to the FLASH address to be programmed 7 Wait for a time, tPROG Completed programming this row? Y N NOTE: The time between each FLASH address change (step 6 to step 6), or the time between the last FLASH address programmed to clearing PGM bit (step 6 to step 9) must not exceed the maximum programming time, tPROG max. 9 Clear PGM bit 10 Wait for a time, tnvh 11 Clear HVEN bit 12 Wait for a time, trcv This row program algorithm assumes the row/s to be programmed are initially erased. End of Programming Figure 4-3. FLASH Programming Flowchart MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor FLASH Memory Technical Data 59 FLASH Memory 4.8 FLASH Protection Due to the ability of the on-board charge pump to erase and program the FLASH memory in the target application, provision is made to protect blocks of memory from unintentional erase or program operations due to system malfunction. This protection is done by use of a FLASH block protect register (FLBPR). The FLBPR determines the range of the FLASH memory which is to be protected. The range of the protected area starts from a location defined by FLBPR and ends to the bottom of the FLASH memory ($FFFF). When the memory is protected, the HVEN bit cannot be set in either ERASE or PROGRAM operations. NOTE: When the FLBPR is cleared (all 0’s), the entire FLASH memory is protected from being programmed and erased. When all the bits are set, the entire FLASH memory is accessible for program and erase. 4.8.1 FLASH Block Protect Register The FLASH block protect register is implemented as an 8-bit I/O register. The content of this register determine the starting location of the protected range within the FLASH memory. Address: $FE09 Bit 7 6 5 4 3 2 1 Bit 0 BPR7 BPR6 BPR5 BPR4 BPR3 BPR2 BPR1 BPR0 0 0 0 0 0 0 0 0 Read: Write: Reset: Figure 4-4. FLASH Block Protect Register (FLBPR) BPR[7:0] — FLASH Block Protect Register Bit 7 to Bit 0 BPR[7:1] represent bits [15:9] of a 16-bit memory address; bits [8:0] are logic 0’s. 16-bit memory address Start address of FLASH block protect 0 0 0 0 0 0 0 0 0 BPR[7:1] Figure 4-5. FLASH Block Protect Start Address Technical Data 60 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 FLASH Memory Freescale Semiconductor FLASH Memory ROM-Resident Routines BPR0 is used only for BPR[7:0] = $FF, for no block protection. The resultant 16-bit address is used for specifying the start address of the FLASH memory for block protection. The FLASH is protected from this start address to the end of FLASH memory, at $FFFF. With this mechanism, the protect start address can be X000, X200, X400, X600, X800, XA00, XC00, or XE00 within the FLASH memory. Examples of protect start address: BPR[7:0] Start of Address of Protect Range $00 to $DC The entire FLASH memory is protected. $DE (1101 1110) $DE00 (1101 1110 0000 0000) $E0 (1110 0000) $E000 (1110 0000 0000 0000) $E2 (1110 0010) $E200 (1110 0010 0000 0000) $E4 (1110 0100) $E400 (1110 0100 0000 0000) and so on... $FE $FFE0–$FFFF (User vectors) $FF The entire FLASH memory is not protected. Note: The end address of the protected range is always $FFFF. 4.9 ROM-Resident Routines ROM-resident routines can be called by a program running in user mode or in monitor mode (see Section 10. Monitor ROM (MON)) for FLASH programming, erasing, and verifying. The range of the FLASH memory must be unprotected (see 4.8 FLASH Protection) before calling the erase or programming routine. Table 4-1. ROM-Resident Routines Routine Name Call Address VERIFY $FC03 FLASH verify routine ERASE $FC06 FLASH mass erase routine PROGRAM $FC09 FLASH program routine MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor FLASH Memory Routine Function Technical Data 61 FLASH Memory 4.9.1 Variables The ROM-resident routines use three variables: CTRLBYT, CPUSPD and LADDR; and one data buffer. The minimum size of the data buffer is one byte and the maximum size is 64 bytes. CPUSPD must be set before calling the ERASE or PROGRAM routine, and should be set to four times the value of the CPU internal bus speed in MHz. For example: for CPU speed of 3MHz, CPUSPD should be set to 12. Table 4-2. ROM-Resident Routine Variables Variable Address Description CTRLBYT $0048 Control byte for setting mass erase. CPUSPD $0049 Timing adjustment for different CPU speeds. LADDR $004A–$004B Last FLASH address to be programmed. DATABUF $004C–$008B Data buffer for programming and verifying. 4.9.2 ERASE Routine The ERASE routine erases the entire FLASH memory. The routine does not check for a blank range before or after erase. Table 4-3. ERASE Routine Technical Data 62 Routine ERASE Calling Address $FC06 Stack Use 5 Bytes Input CPUSPD — CPU speed HX — Contains any address in the range to be erased CTRLBYT — Mass erase Mass erase if bit 6 = 1 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 FLASH Memory Freescale Semiconductor FLASH Memory ROM-Resident Routines 4.9.3 PROGRAM Routine The PROGRAM routine programs a range of addresses in FLASH memory, which does not have to be on page boundaries, either at the begin or end address. Table 4-4. PROGRAM Routine Routine PROGRAM Calling Address $FC09 Stack Use 7 Bytes Input CPUSPD — HX — LADDR — DATABUF — CPU speed FLASH start address to be programmed FLASH end address to be programmed Contains the data to be programmed 4.9.4 VERIFY Routine The VERIFY routine reads and verifies a range of FLASH memory. Table 4-5. VERIFY Routine Routine VERIFY Calling Address $FC03 Stack Use 6 Bytes Input HX — FLASH start address to be verified LADDR — FLASH end address to be verified DATABUF — Contains the data to be verified Output C Bit — C bit is set if verify passes DATABUF — Contains the data in the range of the FLASH memory MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor FLASH Memory Technical Data 63 FLASH Memory Technical Data 64 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 FLASH Memory Freescale Semiconductor Technical Data — MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 Section 5. Configuration Register (CONFIG) 5.1 Contents 5.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 5.3 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .66 5.2 Introduction This section describes the configuration register (CONFIG). This writeonce-after-reset register controls the following options: • USB reset • Low voltage inhibit • Stop mode recovery time (2048 or 4096 OSCXCLK cycles) • COP timeout period (218 – 24 or 213 – 24 OSCXCLK cycles) • STOP instruction • Computer operating properly module (COP) MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Configuration Register (CONFIG) Technical Data 65 Configuration Register (CONFIG) 5.3 Functional Description The configuration register is used in the initialization of various options. The configuration register can be written once after each reset. Bit-5 and bit-4 are cleared by a POR or LVI reset only. Bit-3 to bit-0 are cleared during any reset. Since the various options affect the operation of the MCU, it is recommended that this register be written immediately after reset. The configuration register is located at $001F. The configuration register may be read at any time. Address: Read: $001F Bit 7 6 0 0 5 4 3 2 1 Bit 0 URSTD LVID SSREC COPRS STOP COPD 0* 0* 0 0 0 0 Write: Reset: 0 0 = Unimplemented * URSTD and LVID bits are reset by POR or LVI reset only. Figure 5-1. Configuration Register (CONFIG) URSTD — USB Reset Disable Bit URSTD disables the USB reset signal generating an internal reset to the CPU and internal registers. Instead, it will generate an interrupt request to the CPU. 1 = USB reset generates a USB interrupt request to CPU 0 = USB reset generates a chip reset LVID — Low Voltage Inhibit Disable Bit LVID disables the LVI circuit 1 = Disable LVI circuit 0 = Enable LVI circuit SSREC — Short Stop Recovery Bit SSREC enables the CPU to exit stop mode with a delay of 2048×OSCXCLK cycles instead of a 4096×OSCXCLK cycle delay. 1 = Stop mode recovery after 2048×OSCXCLK cycles 0 = Stop mode recovery after 4096×OSCXCLK cycles Technical Data 66 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Configuration Register (CONFIG) Freescale Semiconductor Configuration Register (CONFIG) Functional Description NOTE: Exiting stop mode by pulling reset will result in the long stop recovery. If using an external crystal, do not set the SSREC bit. COPRS — COP Rate Select Bit COPD selects the COP timeout period. Reset clears COPRS. (See Section 15. Computer Operating Properly (COP).) 1 = COP timeout period = (213 – 24)×OSCXCLK cycles 0 = COP timeout period = (218 – 24)×OSCXCLK cycles STOP — STOP Instruction Enable Bit STOP enables the STOP instruction. 1 = STOP instruction enabled 0 = STOP instruction treated as illegal opcode COPD — COP Disable Bit COPD disables the COP module. (See Section 15. Computer Operating Properly (COP).) 1 = COP module disabled 0 = COP module enabled MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Configuration Register (CONFIG) Technical Data 67 Configuration Register (CONFIG) Technical Data 68 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Configuration Register (CONFIG) Freescale Semiconductor Technical Data — MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 Section 6. Central Processor Unit (CPU) 6.1 Contents 6.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 6.3 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 6.4 CPU Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 6.4.1 Accumulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 6.4.2 Index Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 6.4.3 Stack Pointer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 6.4.4 Program Counter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 6.4.5 Condition Code Register . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 6.5 Arithmetic/Logic Unit (ALU) . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 6.6 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 6.6.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .76 6.6.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .77 6.7 CPU During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . 77 6.8 Instruction Set Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 6.9 Opcode Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Central Processor Unit (CPU) Technical Data 69 Central Processor Unit (CPU) 6.2 Introduction The M68HC08 CPU (central processor unit) is an enhanced and fully object-code-compatible version of the M68HC05 CPU. The CPU08 Reference Manual (Freescale document order number CPU08RM/AD) contains a description of the CPU instruction set, addressing modes, and architecture. 6.3 Features Technical Data 70 • Object code fully upward-compatible with M68HC05 Family • 16-bit stack pointer with stack manipulation instructions • 16-bit index register with x-register manipulation instructions • 3-MHz CPU internal bus frequency • 64-Kbyte program/data memory space • 16 addressing modes • Memory-to-memory data moves without using accumulator • Fast 8-bit by 8-bit multiply and 16-bit by 8-bit divide instructions • Enhanced binary-coded decimal (BCD) data handling • Modular architecture with expandable internal bus definition for extension of addressing range beyond 64-Kbytes • Low-power stop and wait modes MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Central Processor Unit (CPU) Freescale Semiconductor Central Processor Unit (CPU) CPU Registers 6.4 CPU Registers Figure 6-1 shows the five CPU registers. CPU registers are not part of the memory map. 0 7 ACCUMULATOR (A) 0 15 H X INDEX REGISTER (H:X) 15 0 STACK POINTER (SP) 15 0 PROGRAM COUNTER (PC) 7 0 V 1 1 H I N Z C CONDITION CODE REGISTER (CCR) CARRY/BORROW FLAG ZERO FLAG NEGATIVE FLAG INTERRUPT MASK HALF-CARRY FLAG TWO’S COMPLEMENT OVERFLOW FLAG Figure 6-1. CPU Registers 6.4.1 Accumulator The accumulator is a general-purpose 8-bit register. The CPU uses the accumulator to hold operands and the results of arithmetic/logic operations. Bit 7 6 5 4 3 2 1 Bit 0 Read: Write: Reset: Unaffected by reset Figure 6-2. Accumulator (A) MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Central Processor Unit (CPU) Technical Data 71 Central Processor Unit (CPU) 6.4.2 Index Register The 16-bit index register allows indexed addressing of a 64-Kbyte memory space. H is the upper byte of the index register, and X is the lower byte. H:X is the concatenated 16-bit index register. In the indexed addressing modes, the CPU uses the contents of the index register to determine the conditional address of the operand. The index register can serve also as a temporary data storage location. Bit 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 Bit 0 0 0 0 0 0 0 0 0 X X X X X X X X Read: Write: Reset: X = Indeterminate Figure 6-3. Index Register (H:X) 6.4.3 Stack Pointer The stack pointer is a 16-bit register that contains the address of the next location on the stack. During a reset, the stack pointer is preset to $00FF. The reset stack pointer (RSP) instruction sets the least significant byte to $FF and does not affect the most significant byte. The stack pointer decrements as data is pushed onto the stack and increments as data is pulled from the stack. In the stack pointer 8-bit offset and 16-bit offset addressing modes, the stack pointer can function as an index register to access data on the stack. The CPU uses the contents of the stack pointer to determine the conditional address of the operand. Bit 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 Bit 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 Read: Write: Reset: Figure 6-4. Stack Pointer (SP) Technical Data 72 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Central Processor Unit (CPU) Freescale Semiconductor Central Processor Unit (CPU) CPU Registers NOTE: The location of the stack is arbitrary and may be relocated anywhere in RAM. Moving the SP out of page 0 ($0000 to $00FF) frees direct address (page 0) space. For correct operation, the stack pointer must point only to RAM locations. 6.4.4 Program Counter The program counter is a 16-bit register that contains the address of the next instruction or operand to be fetched. Normally, the program counter automatically increments to the next sequential memory location every time an instruction or operand is fetched. Jump, branch, and interrupt operations load the program counter with an address other than that of the next sequential location. During reset, the program counter is loaded with the reset vector address located at $FFFE and $FFFF. The vector address is the address of the first instruction to be executed after exiting the reset state. Bit 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 Bit 0 Read: Write: Reset: Loaded with Vector from $FFFE and $FFFF Figure 6-5. Program Counter (PC) MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Central Processor Unit (CPU) Technical Data 73 Central Processor Unit (CPU) 6.4.5 Condition Code Register The 8-bit condition code register contains the interrupt mask and five flags that indicate the results of the instruction just executed. Bits 6 and 5 are set permanently to logic 1. The following paragraphs describe the functions of the condition code register. Bit 7 6 5 4 3 2 1 Bit 0 V 1 1 H I N Z C X 1 1 X 1 X X X Read: Write: Reset: X = Indeterminate Figure 6-6. Condition Code Register (CCR) V — Overflow Flag The CPU sets the overflow flag when a two's complement overflow occurs. The signed branch instructions BGT, BGE, BLE, and BLT use the overflow flag. 1 = Overflow 0 = No overflow H — Half-Carry Flag The CPU sets the half-carry flag when a carry occurs between accumulator bits 3 and 4 during an add-without-carry (ADD) or addwith-carry (ADC) operation. The half-carry flag is required for binarycoded decimal (BCD) arithmetic operations. The DAA instruction uses the states of the H and C flags to determine the appropriate correction factor. 1 = Carry between bits 3 and 4 0 = No carry between bits 3 and 4 Technical Data 74 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Central Processor Unit (CPU) Freescale Semiconductor Central Processor Unit (CPU) CPU Registers I — Interrupt Mask When the interrupt mask is set, all maskable CPU interrupts are disabled. CPU interrupts are enabled when the interrupt mask is cleared. When a CPU interrupt occurs, the interrupt mask is set automatically after the CPU registers are saved on the stack, but before the interrupt vector is fetched. 1 = Interrupts disabled 0 = Interrupts enabled NOTE: To maintain M6805 Family compatibility, the upper byte of the index register (H) is not stacked automatically. If the interrupt service routine modifies H, then the user must stack and unstack H using the PSHH and PULH instructions. After the I bit is cleared, the highest-priority interrupt request is serviced first. A return-from-interrupt (RTI) instruction pulls the CPU registers from the stack and restores the interrupt mask from the stack. After any reset, the interrupt mask is set and can be cleared only by the clear interrupt mask software instruction (CLI). N — Negative flag The CPU sets the negative flag when an arithmetic operation, logic operation, or data manipulation produces a negative result, setting bit 7 of the result. 1 = Negative result 0 = Non-negative result Z — Zero flag The CPU sets the zero flag when an arithmetic operation, logic operation, or data manipulation produces a result of $00. 1 = Zero result 0 = Non-zero result MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Central Processor Unit (CPU) Technical Data 75 Central Processor Unit (CPU) C — Carry/Borrow Flag The CPU sets the carry/borrow flag when an addition operation produces a carry out of bit 7 of the accumulator or when a subtraction operation requires a borrow. Some instructions — such as bit test and branch, shift, and rotate — also clear or set the carry/borrow flag. 1 = Carry out of bit 7 0 = No carry out of bit 7 6.5 Arithmetic/Logic Unit (ALU) The ALU performs the arithmetic and logic operations defined by the instruction set. Refer to the CPU08 Reference Manual (Freescale document order number CPU08RM/AD) for a description of the instructions and addressing modes and more detail about the architecture of the CPU. 6.6 Low-Power Modes The WAIT and STOP instructions put the MCU in low power-consumption standby modes. 6.6.1 Wait Mode The WAIT instruction: Technical Data 76 • Clears the interrupt mask (I bit) in the condition code register, enabling interrupts. After exit from wait mode by interrupt, the I bit remains clear. After exit by reset, the I bit is set. • Disables the CPU clock MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Central Processor Unit (CPU) Freescale Semiconductor Central Processor Unit (CPU) CPU During Break Interrupts 6.6.2 Stop Mode The STOP instruction: • Clears the interrupt mask (I bit) in the condition code register, enabling external interrupts. After exit from stop mode by external interrupt, the I bit remains clear. After exit by reset, the I bit is set. • Disables the CPU clock After exiting stop mode, the CPU clock begins running after the oscillator stabilization delay. 6.7 CPU During Break Interrupts If a break module is present on the MCU, the CPU starts a break interrupt by: • Loading the instruction register with the SWI instruction • Loading the program counter with $FFFC:$FFFD or with $FEFC:$FEFD in monitor mode The break interrupt begins after completion of the CPU instruction in progress. If the break address register match occurs on the last cycle of a CPU instruction, the break interrupt begins immediately. A return-from-interrupt instruction (RTI) in the break routine ends the break interrupt and returns the MCU to normal operation if the break interrupt has been deasserted. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Central Processor Unit (CPU) Technical Data 77 Central Processor Unit (CPU) 6.8 Instruction Set Summary V H I N Z C ADC #opr ADC opr ADC opr ADC opr,X ADC opr,X ADC ,X ADC opr,SP ADC opr,SP A ← (A) + (M) + (C) Add with Carry IMM DIR EXT IX2 R R – R R R IX1 IX SP1 SP2 A9 B9 C9 D9 E9 F9 9EE9 9ED9 ii dd hh ll ee ff ff IMM DIR EXT IX2 R R – R R R IX1 IX SP1 SP2 AB BB CB DB EB FB 9EEB 9EDB ii dd hh ll ee ff ff ff ee ff A7 ii 2 – – – – – – IMM AF ii 2 IMM DIR EXT IX2 0 – – R R – IX1 IX SP1 SP2 A4 B4 C4 D4 E4 F4 9EE4 9ED4 ii dd hh ll ee ff ff 2 3 4 4 3 2 4 5 DIR INH INH R – – R R R IX1 IX SP1 38 48 58 68 78 9E68 dd DIR INH INH R – – R R R IX1 IX SP1 37 47 57 67 77 9E67 dd Add without Carry AIS #opr Add Immediate Value (Signed) to SP SP ← (SP) + (16 « M) – – – – – – IMM AIX #opr Add Immediate Value (Signed) to H:X H:X ← (H:X) + (16 « M) A ← (A) & (M) AND #opr AND opr AND opr AND opr,X AND opr,X AND ,X AND opr,SP AND opr,SP ASL opr ASLA ASLX ASL opr,X ASL ,X ASL opr,SP ASR opr ASRA ASRX ASR opr,X ASR opr,X ASR opr,SP Technical Data 78 Logical AND Arithmetic Shift Left (Same as LSL) C 0 b7 b0 C Arithmetic Shift Right b7 b0 2 3 4 4 3 2 4 5 2 3 4 4 3 2 4 5 ADD #opr ADD opr ADD opr ADD opr,X ADD opr,X ADD ,X ADD opr,SP ADD opr,SP A ← (A) + (M) ff ee ff Cycles Effect on CCR Description Operand Operation Opcode Source Form Address Mode Table 6-1. Instruction Set Summary (Sheet 1 of 9) ff ee ff ff ff ff ff 4 1 1 4 3 5 4 1 1 4 3 5 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Central Processor Unit (CPU) Freescale Semiconductor Central Processor Unit (CPU) Instruction Set Summary Effect on CCR V H I N Z C BCC rel PC ← (PC) + 2 + rel ? (C) = 0 Branch if Carry Bit Clear Mn ← 0 Cycles Description Operand Operation Opcode Source Form Address Mode Table 6-1. Instruction Set Summary (Sheet 2 of 9) – – – – – – REL 24 rr 3 DIR (b0) DIR (b1) DIR (b2) DIR (b3) – – – – – – DIR (b4) DIR (b5) DIR (b6) DIR (b7) 11 13 15 17 19 1B 1D 1F dd dd dd dd dd dd dd dd 4 4 4 4 4 4 4 4 BCLR n, opr Clear Bit n in M BCS rel Branch if Carry Bit Set (Same as BLO) PC ← (PC) + 2 + rel ? (C) = 1 – – – – – – REL 25 rr 3 BEQ rel Branch if Equal PC ← (PC) + 2 + rel ? (Z) = 1 – – – – – – REL 27 rr 3 BGE opr Branch if Greater Than or Equal To (Signed Operands) PC ← (PC) + 2 + rel ? (N ⊕ V) = 0 – – – – – – REL 90 rr 3 BGT opr Branch if Greater Than (Signed Operands) PC ← (PC) + 2 + rel ? (Z) | (N ⊕ V) = 0 – – – – – – REL 92 rr 3 BHCC rel Branch if Half Carry Bit Clear PC ← (PC) + 2 + rel ? (H) = 0 – – – – – – REL 28 rr 3 BHCS rel Branch if Half Carry Bit Set PC ← (PC) + 2 + rel ? (H) = 1 – – – – – – REL 29 rr 3 BHI rel Branch if Higher PC ← (PC) + 2 + rel ? (C) | (Z) = 0 – – – – – – REL 22 rr 3 BHS rel Branch if Higher or Same (Same as BCC) PC ← (PC) + 2 + rel ? (C) = 0 – – – – – – REL 24 rr 3 BIH rel Branch if IRQ Pin High PC ← (PC) + 2 + rel ? IRQ = 1 – – – – – – REL 2F rr 3 BIL rel Branch if IRQ Pin Low PC ← (PC) + 2 + rel ? IRQ = 0 – – – – – – REL 2E rr 3 (A) & (M) IMM DIR EXT IX2 0 – – R R – IX1 IX SP1 SP2 A5 B5 C5 D5 E5 F5 9EE5 9ED5 ii dd hh ll ee ff ff ff ee ff 2 3 4 4 3 2 4 5 BIT #opr BIT opr BIT opr BIT opr,X BIT opr,X BIT ,X BIT opr,SP BIT opr,SP Bit Test BLE opr Branch if Less Than or Equal To (Signed Operands) PC ← (PC) + 2 + rel ? (Z) | (N ⊕ V) = 1 – – – – – – REL 93 rr 3 BLO rel Branch if Lower (Same as BCS) PC ← (PC) + 2 + rel ? (C) = 1 – – – – – – REL 25 rr 3 BLS rel Branch if Lower or Same PC ← (PC) + 2 + rel ? (C) | (Z) = 1 – – – – – – REL 23 rr 3 BLT opr Branch if Less Than (Signed Operands) PC ← (PC) + 2 + rel ? (N ⊕ V) =1 – – – – – – REL 91 rr 3 BMC rel Branch if Interrupt Mask Clear PC ← (PC) + 2 + rel ? (I) = 0 – – – – – – REL 2C rr 3 BMI rel Branch if Minus PC ← (PC) + 2 + rel ? (N) = 1 – – – – – – REL 2B rr 3 BMS rel Branch if Interrupt Mask Set PC ← (PC) + 2 + rel ? (I) = 1 – – – – – – REL 2D rr 3 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Central Processor Unit (CPU) Technical Data 79 Central Processor Unit (CPU) Effect on CCR V H I N Z C Cycles Description Operand Operation Opcode Source Form Address Mode Table 6-1. Instruction Set Summary (Sheet 3 of 9) BNE rel Branch if Not Equal PC ← (PC) + 2 + rel ? (Z) = 0 – – – – – – REL 26 rr 3 BPL rel Branch if Plus PC ← (PC) + 2 + rel ? (N) = 0 – – – – – – REL 2A rr 3 BRA rel Branch Always PC ← (PC) + 2 + rel – – – – – – REL 20 rr 3 DIR (b0) DIR (b1) DIR (b2) DIR (b3) – – – – – R DIR (b4) DIR (b5) DIR (b6) DIR (b7) 01 03 05 07 09 0B 0D 0F dd rr dd rr dd rr dd rr dd rr dd rr dd rr dd rr 5 5 5 5 5 5 5 5 – – – – – – REL 21 rr 3 PC ← (PC) + 3 + rel ? (Mn) = 1 DIR (b0) DIR (b1) DIR (b2) DIR (b3) – – – – – R DIR (b4) DIR (b5) DIR (b6) DIR (b7) 00 02 04 06 08 0A 0C 0E dd rr dd rr dd rr dd rr dd rr dd rr dd rr dd rr 5 5 5 5 5 5 5 5 Mn ← 1 DIR (b0) DIR (b1) DIR (b2) DIR (b3) – – – – – – DIR (b4) DIR (b5) DIR (b6) DIR (b7) 10 12 14 16 18 1A 1C 1E dd dd dd dd dd dd dd dd 4 4 4 4 4 4 4 4 – – – – – – REL AD rr 4 dd rr ii rr ii rr ff rr rr ff rr 5 4 4 5 4 6 BRCLR n,opr,rel Branch if Bit n in M Clear BRN rel Branch Never BRSET n,opr,rel Branch if Bit n in M Set BSET n,opr BSR rel Set Bit n in M Branch to Subroutine CBEQ opr,rel CBEQA #opr,rel CBEQX #opr,rel Compare and Branch if Equal CBEQ opr,X+,rel CBEQ X+,rel CBEQ opr,SP,rel PC ← (PC) + 3 + rel ? (Mn) = 0 PC ← (PC) + 2 PC ← (PC) + 2; push (PCL) SP ← (SP) – 1; push (PCH) SP ← (SP) – 1 PC ← (PC) + rel DIR PC ← (PC) + 3 + rel ? (A) – (M) = $00 IMM PC ← (PC) + 3 + rel ? (A) – (M) = $00 IMM PC ← (PC) + 3 + rel ? (X) – (M) = $00 – – – – – – IX1+ PC ← (PC) + 3 + rel ? (A) – (M) = $00 IX+ PC ← (PC) + 2 + rel ? (A) – (M) = $00 SP1 PC ← (PC) + 4 + rel ? (A) – (M) = $00 31 41 51 61 71 9E61 CLC Clear Carry Bit C←0 – – – – – 0 INH 98 1 CLI Clear Interrupt Mask I←0 – – 0 – – – INH 9A 2 Technical Data 80 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Central Processor Unit (CPU) Freescale Semiconductor Central Processor Unit (CPU) Instruction Set Summary Effect on CCR V H I N Z C CLR opr CLRA CLRX CLRH CLR opr,X CLR ,X CLR opr,SP CMP #opr CMP opr CMP opr CMP opr,X CMP opr,X CMP ,X CMP opr,SP CMP opr,SP Clear Compare A with M COM opr COMA COMX COM opr,X COM ,X COM opr,SP Complement (One’s Complement) CPHX #opr CPHX opr Compare H:X with M CPX #opr CPX opr CPX opr CPX ,X CPX opr,X CPX opr,X CPX opr,SP CPX opr,SP Compare X with M DAA Decimal Adjust A M ← $00 A ← $00 X ← $00 H ← $00 M ← $00 M ← $00 M ← $00 DIR INH INH 0 – – 0 1 – INH IX1 IX SP1 3F 4F 5F 8C 6F 7F 9E6F dd (A) – (M) IMM DIR EXT IX2 R – – R R R IX1 IX SP1 SP2 A1 B1 C1 D1 E1 F1 9EE1 9ED1 ii dd hh ll ee ff ff DIR INH INH 0 – – R R 1 IX1 IX SP1 33 43 53 63 73 9E63 dd M ← (M) = $FF – (M) A ← (A) = $FF – (M) X ← (X) = $FF – (M) M ← (M) = $FF – (M) M ← (M) = $FF – (M) M ← (M) = $FF – (M) ff ff ff ee ff Cycles Description Operand Operation Opcode Source Form Address Mode Table 6-1. Instruction Set Summary (Sheet 4 of 9) 3 1 1 1 3 2 4 2 3 4 4 3 2 4 5 ff 4 1 1 4 3 5 65 75 ii ii+1 dd 3 4 IMM DIR EXT IX2 R – – R R R IX1 IX SP1 SP2 A3 B3 C3 D3 E3 F3 9EE3 9ED3 ii dd hh ll ee ff ff 2 3 4 4 3 2 4 5 U – – R R R INH 72 PC ← (PC) + 3 + rel ? (result) ≠ 0 PC ← (PC) + 2 + rel ? (result) ≠ 0 PC ← (PC) + 2 + rel ? (result) ≠ 0 PC ← (PC) + 3 + rel ? (result) ≠ 0 PC ← (PC) + 2 + rel ? (result) ≠ 0 PC ← (PC) + 4 + rel ? (result) ≠ 0 DIR INH – – – – – – INH IX1 IX SP1 3B 4B 5B 6B 7B 9E6B dd rr rr rr ff rr rr ff rr 5 3 3 5 4 6 M ← (M) – 1 A ← (A) – 1 X ← (X) – 1 M ← (M) – 1 M ← (M) – 1 M ← (M) – 1 DIR INH INH R – – R R – IX1 IX SP1 3A 4A 5A 6A 7A 9E6A dd 4 1 1 4 3 5 A ← (H:A)/(X) H ← Remainder – – – – R R INH 52 (H:X) – (M:M + 1) (X) – (M) (A)10 R – – R R R IMM DIR ff ff ee ff 2 A ← (A) – 1 or M ← (M) – 1 or X ← (X) – 1 DBNZ opr,rel DBNZA rel Decrement and Branch if Not Zero DBNZX rel DBNZ opr,X,rel DBNZ X,rel DBNZ opr,SP,rel DEC opr DECA DECX DEC opr,X DEC ,X DEC opr,SP Decrement DIV Divide MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Central Processor Unit (CPU) ff ff 7 Technical Data 81 Central Processor Unit (CPU) V H I N Z C EOR #opr EOR opr EOR opr EOR opr,X EOR opr,X EOR ,X EOR opr,SP EOR opr,SP INC opr INCA INCX INC opr,X INC ,X INC opr,SP JMP opr JMP opr JMP opr,X JMP opr,X JMP ,X JSR opr JSR opr JSR opr,X JSR opr,X JSR ,X LDHX #opr LDHX opr Load H:X from M LSL opr LSLA LSLX LSL opr,X LSL ,X LSL opr,SP Technical Data 82 ii dd hh ll ee ff ff M ← (M) + 1 A ← (A) + 1 X ← (X) + 1 M ← (M) + 1 M ← (M) + 1 M ← (M) + 1 DIR INH INH R – – R R – IX1 IX SP1 3C 4C 5C 6C 7C 9E6C dd PC ← Jump Address DIR EXT – – – – – – IX2 IX1 IX BC CC DC EC FC dd hh ll ee ff ff 2 3 4 3 2 PC ← (PC) + n (n = 1, 2, or 3) Push (PCL); SP ← (SP) – 1 Push (PCH); SP ← (SP) – 1 PC ← Unconditional Address DIR EXT – – – – – – IX2 IX1 IX BD CD DD ED FD dd hh ll ee ff ff 4 5 6 5 4 A ← (M) IMM DIR EXT IX2 0 – – R R – IX1 IX SP1 SP2 A6 B6 C6 D6 E6 F6 9EE6 9ED6 ii dd hh ll ee ff ff ff ee ff 2 3 4 4 3 2 4 5 ii jj dd 3 4 2 3 4 4 3 2 4 5 A ← (A ⊕ M) Jump Load A from M LDX #opr LDX opr LDX opr LDX opr,X LDX opr,X LDX ,X LDX opr,SP LDX opr,SP A8 B8 C8 D8 E8 F8 9EE8 9ED8 Increment LDA #opr LDA opr LDA opr LDA opr,X LDA opr,X LDA ,X LDA opr,SP LDA opr,SP H:X ← (M:M + 1) 0 – – R R – X ← (M) Load X from M Logical Shift Left (Same as ASL) 2 3 4 4 3 2 4 5 IMM DIR EXT IX2 0 – – R R – IX1 IX SP1 SP2 Exclusive OR M with A Jump to Subroutine Cycles Effect on CCR Description Operand Operation Opcode Source Form Address Mode Table 6-1. Instruction Set Summary (Sheet 5 of 9) C 0 b7 b0 IMM DIR 45 55 ff ee ff ff ff IMM DIR EXT IX2 0 – – R R – IX1 IX SP1 SP2 AE BE CE DE EE FE 9EEE 9EDE ii dd hh ll ee ff ff DIR INH INH R – – R R R IX1 IX SP1 38 48 58 68 78 9E68 dd ff ee ff ff ff 4 1 1 4 3 5 4 1 1 4 3 5 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Central Processor Unit (CPU) Freescale Semiconductor Central Processor Unit (CPU) Instruction Set Summary V H I N Z C LSR opr LSRA LSRX LSR opr,X LSR ,X LSR opr,SP Logical Shift Right DIR INH INH R – – 0 R R IX1 IX SP1 34 44 54 64 74 9E64 DD DIX+ 0 – – R R – IMD IX+D 4E 5E 6E 7E X:A ← (X) × (A) – 0 – – – 0 INH 42 M ← –(M) = $00 – (M) A ← –(A) = $00 – (A) X ← –(X) = $00 – (X) M ← –(M) = $00 – (M) M ← –(M) = $00 – (M) DIR INH INH R – – R R R IX1 IX SP1 30 40 50 60 70 9E60 0 C b7 MOV opr,opr MOV opr,X+ MOV #opr,opr MOV X+,opr Move MUL Unsigned multiply b0 (M)Destination ← (M)Source H:X ← (H:X) + 1 (IX+D, DIX+) dd Cycles Effect on CCR Description Operand Operation Opcode Source Form Address Mode Table 6-1. Instruction Set Summary (Sheet 6 of 9) ff 4 1 1 4 3 5 dd dd dd ii dd dd 5 4 4 4 ff 5 dd 4 1 1 4 3 5 NEG opr NEGA NEGX NEG opr,X NEG ,X NEG opr,SP Negate (Two’s Complement) NOP No Operation None – – – – – – INH 9D 1 NSA Nibble Swap A A ← (A[3:0]:A[7:4]) – – – – – – INH 62 3 A ← (A) | (M) IMM DIR EXT IX2 0 – – R R – IX1 IX SP1 SP2 AA BA CA DA EA FA 9EEA 9EDA ff ff ORA #opr ORA opr ORA opr ORA opr,X ORA opr,X ORA ,X ORA opr,SP ORA opr,SP Inclusive OR A and M PSHA Push A onto Stack Push (A); SP ← (SP) – 1 – – – – – – INH 87 2 PSHH Push H onto Stack Push (H); SP ← (SP) – 1 – – – – – – INH 8B 2 PSHX Push X onto Stack Push (X); SP ← (SP) – 1 – – – – – – INH 89 2 PULA Pull A from Stack SP ← (SP + 1); Pull (A) – – – – – – INH 86 2 PULH Pull H from Stack SP ← (SP + 1); Pull (H) – – – – – – INH 8A 2 PULX Pull X from Stack SP ← (SP + 1); Pull (X) – – – – – – INH 88 2 C DIR INH INH R – – R R R IX1 IX SP1 39 49 59 69 79 9E69 ROL opr ROLA ROLX ROL opr,X ROL ,X ROL opr,SP Rotate Left through Carry b7 b0 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Central Processor Unit (CPU) ii dd hh ll ee ff ff ff ee ff dd ff ff 2 3 4 4 3 2 4 5 4 1 1 4 3 5 Technical Data 83 Central Processor Unit (CPU) V H I N Z C ROR opr RORA RORX ROR opr,X ROR ,X ROR opr,SP Rotate Right through Carry RSP Reset Stack Pointer RTI Return from Interrupt RTS Return from Subroutine dd Cycles Effect on CCR Description Operand Operation Opcode Source Form Address Mode Table 6-1. Instruction Set Summary (Sheet 7 of 9) 4 1 1 4 3 5 DIR INH INH R – – R R R IX1 IX SP1 36 46 56 66 76 9E66 SP ← $FF – – – – – – INH 9C 1 SP ← (SP) + 1; Pull (CCR) SP ← (SP) + 1; Pull (A) SP ← (SP) + 1; Pull (X) SP ← (SP) + 1; Pull (PCH) SP ← (SP) + 1; Pull (PCL) R R R R R R INH 80 7 SP ← SP + 1; Pull (PCH) SP ← SP + 1; Pull (PCL) – – – – – – INH 81 4 A ← (A) – (M) – (C) IMM DIR EXT IX2 R – – R R R IX1 IX SP1 SP2 A2 B2 C2 D2 E2 F2 9EE2 9ED2 C b7 b0 ff ff SBC #opr SBC opr SBC opr SBC opr,X SBC opr,X SBC ,X SBC opr,SP SBC opr,SP Subtract with Carry SEC Set Carry Bit C←1 – – – – – 1 INH 99 1 SEI Set Interrupt Mask I←1 – – 1 – – – INH 9B 2 M ← (A) DIR EXT IX2 0 – – R R – IX1 IX SP1 SP2 B7 C7 D7 E7 F7 9EE7 9ED7 (M:M + 1) ← (H:X) 0 – – R R – DIR 35 I ← 0; Stop Oscillator – – 0 – – – INH 8E M ← (X) DIR EXT IX2 0 – – R R – IX1 IX SP1 SP2 BF CF DF EF FF 9EEF 9EDF STA opr STA opr STA opr,X STA opr,X STA ,X STA opr,SP STA opr,SP Store A in M STHX opr Store H:X in M STOP Enable IRQ Pin; Stop Oscillator STX opr STX opr STX opr,X STX opr,X STX ,X STX opr,SP STX opr,SP Technical Data 84 Store X in M ii dd hh ll ee ff ff ff ee ff 2 3 4 4 3 2 4 5 ff ee ff 3 4 4 3 2 4 5 dd 4 dd hh ll ee ff ff 1 dd hh ll ee ff ff ff ee ff 3 4 4 3 2 4 5 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Central Processor Unit (CPU) Freescale Semiconductor Central Processor Unit (CPU) Instruction Set Summary Effect on CCR V H I N Z C SUB #opr SUB opr SUB opr SUB opr,X SUB opr,X SUB ,X SUB opr,SP SUB opr,SP Subtract A ← (A) – (M) ii dd hh ll ee ff ff Cycles Description Operand Operation Opcode Source Form Address Mode Table 6-1. Instruction Set Summary (Sheet 8 of 9) 2 3 4 4 3 2 4 5 IMM DIR EXT IX2 R – – R R R IX1 IX SP1 SP2 A0 B0 C0 D0 E0 F0 9EE0 9ED0 – – 1 – – – INH 83 9 ff ee ff SWI Software Interrupt PC ← (PC) + 1; Push (PCL) SP ← (SP) – 1; Push (PCH) SP ← (SP) – 1; Push (X) SP ← (SP) – 1; Push (A) SP ← (SP) – 1; Push (CCR) SP ← (SP) – 1; I ← 1 PCH ← Interrupt Vector High Byte PCL ← Interrupt Vector Low Byte TAP Transfer A to CCR CCR ← (A) R R R R R R INH 84 2 TAX Transfer A to X X ← (A) – – – – – – INH 97 1 TPA Transfer CCR to A A ← (CCR) – – – – – – INH 85 1 (A) – $00 or (X) – $00 or (M) – $00 DIR INH INH 0 – – R R – IX1 IX SP1 3D 4D 5D 6D 7D 9E6D H:X ← (SP) + 1 – – – – – – INH 95 2 A ← (X) – – – – – – INH 9F 1 (SP) ← (H:X) – 1 – – – – – – INH 94 2 TST opr TSTA TSTX TST opr,X TST ,X TST opr,SP Test for Negative or Zero TSX Transfer SP to H:X TXA Transfer X to A TXS Transfer H:X to SP MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Central Processor Unit (CPU) dd ff ff 3 1 1 3 2 4 Technical Data 85 Central Processor Unit (CPU) V H I N Z C A C CCR dd dd rr DD DIR DIX+ ee ff EXT ff H H hh ll I ii IMD IMM INH IX IX+ IX+D IX1 IX1+ IX2 M N Accumulator Carry/borrow bit Condition code register Direct address of operand Direct address of operand and relative offset of branch instruction Direct to direct addressing mode Direct addressing mode Direct to indexed with post increment addressing mode High and low bytes of offset in indexed, 16-bit offset addressing Extended addressing mode Offset byte in indexed, 8-bit offset addressing Half-carry bit Index register high byte High and low bytes of operand address in extended addressing Interrupt mask Immediate operand byte Immediate source to direct destination addressing mode Immediate addressing mode Inherent addressing mode Indexed, no offset addressing mode Indexed, no offset, post increment addressing mode Indexed with post increment to direct addressing mode Indexed, 8-bit offset addressing mode Indexed, 8-bit offset, post increment addressing mode Indexed, 16-bit offset addressing mode Memory location Negative bit n opr PC PCH PCL REL rel rr SP1 SP2 SP U V X Z & | ⊕ () –( ) # « ← ? : R — Cycles Effect on CCR Description Operand Operation Opcode Source Form Address Mode Table 6-1. Instruction Set Summary (Sheet 9 of 9) Any bit Operand (one or two bytes) Program counter Program counter high byte Program counter low byte Relative addressing mode Relative program counter offset byte Relative program counter offset byte Stack pointer, 8-bit offset addressing mode Stack pointer 16-bit offset addressing mode Stack pointer Undefined Overflow bit Index register low byte Zero bit Logical AND Logical OR Logical EXCLUSIVE OR Contents of Negation (two’s complement) Immediate value Sign extend Loaded with If Concatenated with Set or cleared Not affected 6.9 Opcode Map See Table 6-2. Technical Data 86 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Central Processor Unit (CPU) Freescale Semiconductor Central Processor Unit (CPU) MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Table 6-2. Opcode Map Bit Manipulation DIR DIR MSB Branch REL DIR INH 3 4 0 1 2 5 BRSET0 3 DIR 5 BRCLR0 3 DIR 5 BRSET1 3 DIR 5 BRCLR1 3 DIR 5 BRSET2 3 DIR 5 BRCLR2 3 DIR 5 BRSET3 3 DIR 5 BRCLR3 3 DIR 5 BRSET4 3 DIR 5 BRCLR4 3 DIR 5 BRSET5 3 DIR 5 BRCLR5 3 DIR 5 BRSET6 3 DIR 5 BRCLR6 3 DIR 5 BRSET7 3 DIR 5 BRCLR7 3 DIR 4 BSET0 2 DIR 4 BCLR0 2 DIR 4 BSET1 2 DIR 4 BCLR1 2 DIR 4 BSET2 2 DIR 4 BCLR2 2 DIR 4 BSET3 2 DIR 4 BCLR3 2 DIR 4 BSET4 2 DIR 4 BCLR4 2 DIR 4 BSET5 2 DIR 4 BCLR5 2 DIR 4 BSET6 2 DIR 4 BCLR6 2 DIR 4 BSET7 2 DIR 4 BCLR7 2 DIR 3 BRA 2 REL 3 BRN 2 REL 3 BHI 2 REL 3 BLS 2 REL 3 BCC 2 REL 3 BCS 2 REL 3 BNE 2 REL 3 BEQ 2 REL 3 BHCC 2 REL 3 BHCS 2 REL 3 BPL 2 REL 3 BMI 2 REL 3 BMC 2 REL 3 BMS 2 REL 3 BIL 2 REL 3 BIH 2 REL Read-Modify-Write INH IX1 5 6 1 NEGX 1 INH 4 CBEQX 3 IMM 7 DIV 1 INH 1 COMX 1 INH 1 LSRX 1 INH 4 LDHX 2 DIR 1 RORX 1 INH 1 ASRX 1 INH 1 LSLX 1 INH 1 ROLX 1 INH 1 DECX 1 INH 3 DBNZX 2 INH 1 INCX 1 INH 1 TSTX 1 INH 4 MOV 2 DIX+ 1 CLRX 1 INH 4 NEG 2 IX1 5 CBEQ 3 IX1+ 3 NSA 1 INH 4 COM 2 IX1 4 LSR 2 IX1 3 CPHX 3 IMM 4 ROR 2 IX1 4 ASR 2 IX1 4 LSL 2 IX1 4 ROL 2 IX1 4 DEC 2 IX1 5 DBNZ 3 IX1 4 INC 2 IX1 3 TST 2 IX1 4 MOV 3 IMD 3 CLR 2 IX1 SP1 IX 9E6 7 Control INH INH 8 9 Register/Memory IX2 SP2 IMM DIR EXT A B C D 9ED 4 SUB 3 EXT 4 CMP 3 EXT 4 SBC 3 EXT 4 CPX 3 EXT 4 AND 3 EXT 4 BIT 3 EXT 4 LDA 3 EXT 4 STA 3 EXT 4 EOR 3 EXT 4 ADC 3 EXT 4 ORA 3 EXT 4 ADD 3 EXT 3 JMP 3 EXT 5 JSR 3 EXT 4 LDX 3 EXT 4 STX 3 EXT 4 SUB 3 IX2 4 CMP 3 IX2 4 SBC 3 IX2 4 CPX 3 IX2 4 AND 3 IX2 4 BIT 3 IX2 4 LDA 3 IX2 4 STA 3 IX2 4 EOR 3 IX2 4 ADC 3 IX2 4 ORA 3 IX2 4 ADD 3 IX2 4 JMP 3 IX2 6 JSR 3 IX2 4 LDX 3 IX2 4 STX 3 IX2 5 SUB 4 SP2 5 CMP 4 SP2 5 SBC 4 SP2 5 CPX 4 SP2 5 AND 4 SP2 5 BIT 4 SP2 5 LDA 4 SP2 5 STA 4 SP2 5 EOR 4 SP2 5 ADC 4 SP2 5 ORA 4 SP2 5 ADD 4 SP2 IX1 SP1 IX E 9EE F LSB 0 1 2 3 4 5 6 7 8 9 A B C E F 87 Technical Data INH Inherent REL Relative IMM Immediate IX Indexed, No Offset DIR Direct IX1 Indexed, 8-Bit Offset EXT Extended IX2 Indexed, 16-Bit Offset DD Direct-Direct IMD Immediate-Direct IX+D Indexed-Direct DIX+ Direct-Indexed *Pre-byte for stack pointer indexed instructions 5 3 NEG NEG 3 SP1 1 IX 6 4 CBEQ CBEQ 4 SP1 2 IX+ 2 DAA 1 INH 5 3 COM COM 3 SP1 1 IX 5 3 LSR LSR 3 SP1 1 IX 4 CPHX 2 DIR 5 3 ROR ROR 3 SP1 1 IX 5 3 ASR ASR 3 SP1 1 IX 5 3 LSL LSL 3 SP1 1 IX 5 3 ROL ROL 3 SP1 1 IX 5 3 DEC DEC 3 SP1 1 IX 6 4 DBNZ DBNZ 4 SP1 2 IX 5 3 INC INC 3 SP1 1 IX 4 2 TST TST 3 SP1 1 IX 4 MOV 2 IX+D 4 2 CLR CLR 3 SP1 1 IX SP1 Stack Pointer, 8-Bit Offset SP2 Stack Pointer, 16-Bit Offset IX+ Indexed, No Offset with Post Increment IX1+ Indexed, 1-Byte Offset with Post Increment 7 3 RTI BGE 1 INH 2 REL 4 3 RTS BLT 1 INH 2 REL 3 BGT 2 REL 9 3 SWI BLE 1 INH 2 REL 2 2 TAP TXS 1 INH 1 INH 1 2 TPA TSX 1 INH 1 INH 2 PULA 1 INH 2 1 PSHA TAX 1 INH 1 INH 2 1 PULX CLC 1 INH 1 INH 2 1 PSHX SEC 1 INH 1 INH 2 2 PULH CLI 1 INH 1 INH 2 2 PSHH SEI 1 INH 1 INH 1 1 CLRH RSP 1 INH 1 INH 1 NOP 1 INH 1 STOP * 1 INH 1 1 WAIT TXA 1 INH 1 INH 2 SUB 2 IMM 2 CMP 2 IMM 2 SBC 2 IMM 2 CPX 2 IMM 2 AND 2 IMM 2 BIT 2 IMM 2 LDA 2 IMM 2 AIS 2 IMM 2 EOR 2 IMM 2 ADC 2 IMM 2 ORA 2 IMM 2 ADD 2 IMM 3 SUB 2 DIR 3 CMP 2 DIR 3 SBC 2 DIR 3 CPX 2 DIR 3 AND 2 DIR 3 BIT 2 DIR 3 LDA 2 DIR 3 STA 2 DIR 3 EOR 2 DIR 3 ADC 2 DIR 3 ORA 2 DIR 3 ADD 2 DIR 2 JMP 2 DIR 4 4 BSR JSR 2 REL 2 DIR 2 3 LDX LDX 2 IMM 2 DIR 2 3 AIX STX 2 IMM 2 DIR MSB 0 3 SUB 2 IX1 3 CMP 2 IX1 3 SBC 2 IX1 3 CPX 2 IX1 3 AND 2 IX1 3 BIT 2 IX1 3 LDA 2 IX1 3 STA 2 IX1 3 EOR 2 IX1 3 ADC 2 IX1 3 ORA 2 IX1 3 ADD 2 IX1 3 JMP 2 IX1 5 JSR 2 IX1 5 3 LDX LDX 4 SP2 2 IX1 5 3 STX STX 4 SP2 2 IX1 4 SUB 3 SP1 4 CMP 3 SP1 4 SBC 3 SP1 4 CPX 3 SP1 4 AND 3 SP1 4 BIT 3 SP1 4 LDA 3 SP1 4 STA 3 SP1 4 EOR 3 SP1 4 ADC 3 SP1 4 ORA 3 SP1 4 ADD 3 SP1 2 SUB 1 IX 2 CMP 1 IX 2 SBC 1 IX 2 CPX 1 IX 2 AND 1 IX 2 BIT 1 IX 2 LDA 1 IX 2 STA 1 IX 2 EOR 1 IX 2 ADC 1 IX 2 ORA 1 IX 2 ADD 1 IX 2 JMP 1 IX 4 JSR 1 IX 4 2 LDX LDX 3 SP1 1 IX 4 2 STX STX 3 SP1 1 IX High Byte of Opcode in Hexadecimal LSB Low Byte of Opcode in Hexadecimal 0 Cycles 5 BRSET0 Opcode Mnemonic 3 DIR Number of Bytes / Addressing Mode Central Processor Unit (CPU) Opcode Map D 4 1 NEG NEGA 2 DIR 1 INH 5 4 CBEQ CBEQA 3 DIR 3 IMM 5 MUL 1 INH 4 1 COM COMA 2 DIR 1 INH 4 1 LSR LSRA 2 DIR 1 INH 4 3 STHX LDHX 2 DIR 3 IMM 4 1 ROR RORA 2 DIR 1 INH 4 1 ASR ASRA 2 DIR 1 INH 4 1 LSL LSLA 2 DIR 1 INH 4 1 ROL ROLA 2 DIR 1 INH 4 1 DEC DECA 2 DIR 1 INH 5 3 DBNZ DBNZA 3 DIR 2 INH 4 1 INC INCA 2 DIR 1 INH 3 1 TST TSTA 2 DIR 1 INH 5 MOV 3 DD 3 1 CLR CLRA 2 DIR 1 INH Central Processor Unit (CPU) Technical Data 88 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Central Processor Unit (CPU) Freescale Semiconductor Technical Data — MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 Section 7. Oscillator (OSC) 7.1 Contents 7.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 7.3 Oscillator External Connections . . . . . . . . . . . . . . . . . . . . . . . .90 7.4 I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 7.4.1 Crystal Amplifier Input Pin (OSC1). . . . . . . . . . . . . . . . . . . . 91 7.4.2 Crystal Amplifier Output Pin (OSC2) . . . . . . . . . . . . . . . . . . 91 7.4.3 Oscillator Enable Signal (SIMOSCEN). . . . . . . . . . . . . . . . . 91 7.4.4 External Clock Source (OSCXCLK) . . . . . . . . . . . . . . . . . . . 91 7.4.5 Oscillator Out (OSCOUT). . . . . . . . . . . . . . . . . . . . . . . . . . . 92 7.5 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 7.5.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .92 7.5.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .92 7.6 Oscillator During Break Mode. . . . . . . . . . . . . . . . . . . . . . . . . . 92 7.2 Introduction The oscillator circuit is designed for use with crystals or ceramic resonators. The oscillator circuit generates the crystal clock signal. The crystal oscillator output signal passes through the clock doubler. OSCXCLK is the output signal of the clock doubler. OSCXCLK is divided by two before being passed on to the system integration module (SIM) for bus clock generation. Figure 7-1 shows the structure of the oscillator. The oscillator requires various external components. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Oscillator (OSC) Technical Data 89 Oscillator (OSC) 7.3 Oscillator External Connections In its typical configuration, the oscillator requires five external components. The crystal oscillator is normally connected in a Pierce oscillator configuration, as shown in Figure 7-1. This figure shows only the logical representation of the internal components and may not represent actual circuitry. The oscillator configuration uses five components: • Crystal, X1 • Fixed capacitor, C1 • Tuning capacitor, C2 (can also be a fixed capacitor) • Feedback resistor, RB • Series resistor, RS (optional) FROM SIM TO USB TO SIM CLOCK DOUBLER OSCXCLK TO SIM ÷2 OSCOUT SIMOSCEN MCU OSC1 OSC2 RB RS * X1 C1 C2 * RS can be 0 (shorted) when used with higher frequency crystals. Refer to manufacturer’s data. Figure 7-1. Oscillator External Connections Technical Data 90 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Oscillator (OSC) Freescale Semiconductor Oscillator (OSC) I/O Signals The series resistor (RS) is included in the diagram to follow strict Pierce oscillator guidelines and may not be required for all ranges of operation, especially with high-frequency crystals. Refer to the crystal manufacturer’s data for more information. 7.4 I/O Signals The following paragraphs describe the oscillator input/output (I/O) signals. 7.4.1 Crystal Amplifier Input Pin (OSC1) The OSC1 pin is an input to the crystal oscillator amplifier. 7.4.2 Crystal Amplifier Output Pin (OSC2) The OSC2 pin is the output of the crystal oscillator inverting amplifier. 7.4.3 Oscillator Enable Signal (SIMOSCEN) The SIMOSCEN signal comes from the system integration module (SIM) and enables the oscillator. 7.4.4 External Clock Source (OSCXCLK) The crystal oscillator output signal passes through the clock doubler and OSCXCLK is the output signal of the clock doubler. OSCXCLK runs at twice the speed of the crystal (fXCLK). Figure 7-1 shows only the logical relation of OSCXCLK to OSC1 and OSC2 and may not represent the actual circuitry. The duty cycle of OSCXCLK is unknown and may depend on the crystal and other external factors. Also, the frequency and amplitude of OSCXCLK can be unstable at startup. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Oscillator (OSC) Technical Data 91 Oscillator (OSC) 7.4.5 Oscillator Out (OSCOUT) The clock driven to the SIM is OSCXCLK. This signal is driven to the SIM for generation of the bus clocks used by the CPU and other modules on the MCU. OSCOUT will be divided again in the SIM and results in the internal bus frequency being one forth of the OSCXCLK frequency or one half of the crystal frequency. 7.5 Low-Power Modes The WAIT and STOP instructions put the MCU in low-powerconsumption standby modes. 7.5.1 Wait Mode The WAIT instruction has no effect on the oscillator logic. OSCXCLK continues to drive to the SIM module. 7.5.2 Stop Mode The STOP instruction disables the OSCXCLK output. 7.6 Oscillator During Break Mode The oscillator continues to drive OSCXCLK when the chip enters the break state. Technical Data 92 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Oscillator (OSC) Freescale Semiconductor Technical Data — MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 Section 8. System Integration Module (SIM) 8.1 Contents 8.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94 8.3 SIM Bus Clock Control and Generation . . . . . . . . . . . . . . . . . . 96 8.3.1 Bus Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 8.3.2 Clock Startup from POR or LVI Reset . . . . . . . . . . . . . . . . . 97 8.3.3 Clocks in Stop Mode and Wait Mode . . . . . . . . . . . . . . . . . . 97 8.4 Reset and System Initialization. . . . . . . . . . . . . . . . . . . . . . . . . 97 8.4.1 External Pin Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98 8.4.2 Active Resets from Internal Sources . . . . . . . . . . . . . . . . . . 99 8.4.2.1 Power-On Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .100 8.4.2.2 Computer Operating Properly (COP) Reset. . . . . . . . . . 101 8.4.2.3 Illegal Opcode Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . 101 8.4.2.4 Illegal Address Reset . . . . . . . . . . . . . . . . . . . . . . . . . . .101 8.4.2.5 Low-Voltage Inhibit (LVI) Reset . . . . . . . . . . . . . . . . . . . 102 8.4.2.6 Universal Serial Bus Reset . . . . . . . . . . . . . . . . . . . . . . 102 8.4.2.7 Registers Values After Different Resets. . . . . . . . . . . . . 102 8.5 SIM Counter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 8.5.1 SIM Counter During Power-On Reset . . . . . . . . . . . . . . . . 103 8.5.2 SIM Counter During Stop Mode Recovery . . . . . . . . . . . . . 104 8.5.3 SIM Counter and Reset States. . . . . . . . . . . . . . . . . . . . . . 104 8.6 Exception Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .104 8.6.1 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104 8.6.1.1 Hardware Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 8.6.1.2 SWI Instruction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108 8.6.2 Interrupt Status Registers. . . . . . . . . . . . . . . . . . . . . . . . . . 108 8.6.2.1 Interrupt Status Register 1 . . . . . . . . . . . . . . . . . . . . . . . 109 8.6.3 Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 8.6.4 Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 8.6.5 Status Flag Protection in Break Mode . . . . . . . . . . . . . . . . 110 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor System Integration Module (SIM) Technical Data 93 System Integration Module (SIM) 8.7 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110 8.7.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .110 8.7.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .112 8.8 SIM Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113 8.8.1 Break Status Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113 8.8.2 Reset Status Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 8.8.3 Break Flag Control Register . . . . . . . . . . . . . . . . . . . . . . .116 8.2 Introduction This section describes the system integration module (SIM), which supports up to 8 external and/or internal interrupts. Together with the CPU, the SIM controls all MCU activities. The SIM is a system state controller that coordinates CPU and exception timing. A block diagram of the SIM is shown in Figure 8-1. Figure 8-2 is a summary of the SIM I/O registers. The SIM is responsible for: • Bus clock generation and control for CPU and peripherals – Stop/wait/reset/break entry and recovery – Internal clock control • Master reset control, including power-on reset (POR) and COP timeout • Interrupt control: – Acknowledge timing – Arbitration control timing – Vector address generation Technical Data 94 • CPU enable/disable timing • Modular architecture expandable to 128 interrupt sources MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 System Integration Module (SIM) Freescale Semiconductor System Integration Module (SIM) Introduction MODULE STOP MODULE WAIT CPU STOP (FROM CPU) CPU WAIT (FROM CPU) STOP/WAIT CONTROL SIMOSCEN (TO OSCILLATOR) SIM COUNTER COP CLOCK OSCXCLK (FROM CLOCK DOUBLER) OSCOUT (FROM CLOCK DOUBLER) ÷2 VDD INTERNAL PULL-UP RESET PIN LOGIC CLOCK CONTROL CLOCK GENERATORS POR CONTROL MASTER RESET CONTROL RESET PIN CONTROL SIM RESET STATUS REGISTER INTERNAL CLOCKS ILLEGAL OPCODE (FROM CPU) ILLEGAL ADDRESS (FROM ADDRESS MAP DECODERS) COP TIMEOUT (FROM COP MODULE) LVI RESET (FROM LVI MODULE) USB RESET (FROM USB MODULE) RESET INTERRUPT SOURCES INTERRUPT CONTROL AND PRIORITY DECODE CPU INTERFACE Figure 8-1. SIM Block Diagram Table 8-1. SIM Module Signal Name Conventions Signal Name Description OSCXCLK Clock doubler output which has twice the frequency of OSC1 from the oscillator OSCOUT The OSCXCLK frequency divided by two. This signal is again divided by two in the SIM to generate the internal bus clocks. (Bus clock = OSCXCLK ÷ 4 = fOSC ÷ 2) IAB Internal address bus IDB Internal data bus PORRST Signal from the power-on reset module to the SIM IRST Internal reset signal R/W Read/write signal MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor System Integration Module (SIM) Technical Data 95 System Integration Module (SIM) Addr. $FE00 Register Name Break Status Register Read: (BSR) Write: Bit 7 6 5 4 3 2 R R R R R R Reset: 1 SBSW See note Bit 0 R 0 Note: Writing a logic 0 clears SBSW. $FE01 Reset Status Register Read: (RSR) Write: POR: $FE02 Reserved Read: Write: $FE03 Break Flag Control Read: Register Write: (BFCR) Reset: $FE04 Interrupt Status Register 1 Read: (INT1) Write: Reset: POR PIN COP ILOP ILAD USB LVI 0 1 0 0 0 0 0 0 0 R R R R R R R R BCFE R R R R R R R IF6 IF5 IF4 IF3 IF2 IF1 0 0 R R R R R R R R 0 0 0 0 0 0 0 0 0 Figure 8-2. SIM I/O Register Summary 8.3 SIM Bus Clock Control and Generation The bus clock generator provides system clock signals for the CPU and peripherals on the MCU. The system clocks are generated from an incoming clock, OSCOUT, as shown in Figure 8-3. FROM CLOCK DOUBLER OSCXCLK FROM CLOCK DOUBLER OSCOUT SIM COUNTER BUS CLOCK GENERATORS ÷2 SIM Figure 8-3. SIM Clock Signals Technical Data 96 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 System Integration Module (SIM) Freescale Semiconductor System Integration Module (SIM) Reset and System Initialization 8.3.1 Bus Timing In user mode, the internal bus frequency is the oscillator frequency divided by two. 8.3.2 Clock Startup from POR or LVI Reset When the power-on reset (POR) module or the low-voltage inhibit module generates a reset, the clocks to the CPU and peripherals are inactive and held in an inactive phase until after the 4096 OSCXCLK cycle POR timeout has completed. The RST pin is driven low by the SIM during this entire period. The IBUS clocks start upon completion of the timeout. 8.3.3 Clocks in Stop Mode and Wait Mode Upon exit from stop mode by an interrupt, break, or reset, the SIM allows OSCXCLK to clock the SIM counter. The CPU and peripheral clocks do not become active until after the stop delay timeout. This timeout is selectable as 4096 or 2048 OSCXCLK cycles. (See 8.7.2 Stop Mode.) In wait mode, the CPU clocks are inactive. The SIM also produces two sets of clocks for other modules. Refer to the wait mode subsection of each module to see if the module is active or inactive in wait mode. Some modules can be programmed to be active in wait mode. 8.4 Reset and System Initialization The MCU has these reset sources: • Power-on reset module (POR) • External reset pin (RST) • Computer operating properly module (COP) • Illegal opcode • Illegal address • Universal serial bus module (USB) • Low-voltage inhibit module (LVI) MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor System Integration Module (SIM) Technical Data 97 System Integration Module (SIM) All of these resets produce the vector $FFFE–FFFF ($FEFE–FEFF in monitor mode) and assert the internal reset signal (IRST). IRST causes all registers to be returned to their default values and all modules to be returned to their reset states. An internal reset clears the SIM counter (see 8.5 SIM Counter), but an external reset does not. Each of the resets sets a corresponding bit in the reset status register (RSR). (See 8.8 SIM Registers.) 8.4.1 External Pin Reset The RST pin circuit includes an internal pullup device. Pulling the asynchronous RST pin low halts all processing. The PIN bit of the reset status register (RSR) is set as long as RST is held low for a minimum of 67 OSCXCLK cycles, assuming that neither the POR nor the LVI was the source of the reset. See Table 8-2 for details. Figure 8-4 shows the relative timing. Table 8-2. PIN Bit Set Timing Reset Type Number of Cycles Required to Set PIN POR/LVI 4163 (4096 + 64 + 3) All others 67 (64 + 3) OSCOUT RST IAB PC VECT H VECT L Figure 8-4. External Reset Timing Technical Data 98 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 System Integration Module (SIM) Freescale Semiconductor System Integration Module (SIM) Reset and System Initialization 8.4.2 Active Resets from Internal Sources All internal reset sources actively pull the RST pin low for 32 OSCXCLK cycles to allow resetting of external peripherals. The internal reset signal IRST continues to be asserted for an additional 32 cycles. (See Figure 8-5.) An internal reset can be caused by an illegal address, illegal opcode, COP timeout, LVI, the USB module or POR. (See Figure 8-6 . Sources of Internal Reset.) NOTE: For LVI or POR resets, the SIM cycles through 4096 OSCXCLK cycles during which the SIM forces the RST pin low. The internal reset signal then follows the sequence from the falling edge of RST shown in Figure 8-5. IRST RST RST PULLED LOW BY MCU 32 CYCLES 32 CYCLES OSCXCLK IAB VECTOR HIGH Figure 8-5. Internal Reset Timing The COP reset is asynchronous to the bus clock. ILLEGAL ADDRESS RST ILLEGAL OPCODE RST COPRST POR LVI USB INTERNAL RESET Figure 8-6. Sources of Internal Reset The active reset feature allows the part to issue a reset to peripherals and other chips within a system built around the MCU. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor System Integration Module (SIM) Technical Data 99 System Integration Module (SIM) 8.4.2.1 Power-On Reset When power is first applied to the MCU, the power-on reset module (POR) generates a pulse to indicate that power-on has occurred. The external reset pin (RST) is held low while the SIM counter counts out 4096 OSCXCLK cycles. Sixty-four OSCXCLK cycles later, the CPU and memories are released from reset to allow the reset vector sequence to occur. At power-on, the following events occur: • A POR pulse is generated. • The internal reset signal is asserted. • The SIM enables the oscillator to drive OSCXCLK. • Internal clocks to the CPU and modules are held inactive for 4096 OSCXCLK cycles to allow stabilization of the oscillator. • The RST pin is driven low during the oscillator stabilization time. • The POR bit of the reset status register (RSR) is set and all other bits in the register are cleared. OSC1 PORRST 4096 CYCLES 32 CYCLES 32 CYCLES OSCXCLK OSCOUT RST $FFFE IAB $FFFF Figure 8-7. POR Recovery Technical Data 100 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 System Integration Module (SIM) Freescale Semiconductor System Integration Module (SIM) Reset and System Initialization 8.4.2.2 Computer Operating Properly (COP) Reset An input to the SIM is reserved for the COP reset signal. The overflow of the COP counter causes an internal reset and sets the COP bit in the reset status register (RSR). The SIM actively pulls down the RST pin for all internal reset sources. To prevent a COP module timeout, write any value to location $FFFF. Writing to location $FFFF clears the COP counter and stages 12 through 5 of the SIM counter. The SIM counter output, which occurs at least every 212 – 24 OSCXCLK cycles, drives the COP counter. The COP should be serviced as soon as possible out of reset to guarantee the maximum amount of time before the first timeout. The COP module is disabled if the RST pin or the IRQ pin is held at VDD + VHI while the MCU is in monitor mode. The COP module can be disabled only through combinational logic conditioned with the high voltage signal on the RST or the IRQ pin. This prevents the COP from becoming disabled as a result of external noise. During a break state, VDD + VHI on the RST pin disables the COP module. 8.4.2.3 Illegal Opcode Reset The SIM decodes signals from the CPU to detect illegal instructions. An illegal instruction sets the ILOP bit in the reset status register (RSR) and causes a reset. If the stop enable bit, STOP, in the mask option register is logic 0, the SIM treats the STOP instruction as an illegal opcode and causes an illegal opcode reset. The SIM actively pulls down the RST pin for all internal reset sources. 8.4.2.4 Illegal Address Reset An opcode fetch from an unmapped address generates an illegal address reset. The SIM verifies that the CPU is fetching an opcode prior to asserting the ILAD bit in the reset status register (RSR) and resetting the MCU. A data fetch from an unmapped address does not generate a reset. The SIM actively pulls down the RST pin for all internal reset sources. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor System Integration Module (SIM) Technical Data 101 System Integration Module (SIM) 8.4.2.5 Low-Voltage Inhibit (LVI) Reset The low-voltage inhibit module (LVI) asserts its output to the SIM when the VDD voltage falls to the LVI reset voltage, VTRIP. The LVI bit in the reset status register (RSR) is set, and the external reset pin (RST) is held low while the SIM counter counts out 4096 OSCXCLK cycles. Sixty-four OSCXCLK cycles later, the CPU is released from reset to allow the reset vector sequence to occur. The SIM actively pulls down the RST pin for all internal reset sources. 8.4.2.6 Universal Serial Bus Reset The USB module will detect a reset signaled on the bus by the presence of an extended SE0 at the USB data pins of a device. The MCU seeing a single-ended 0 on its USB data inputs for more than 2.5 µs treats that signal as a reset. After the reset is removed, the device will be in the attached, but not yet addressed or configured, state (refer to Section 9.1 USB Devices of the Universal Serial Bus Specification Rev. 1.1). The device must be able to accept the device address via a SET_ADDRESS command (refer to Section 9.4 of the Universal Serial Bus Specification Rev. 1.1) no later than 10ms after the reset is removed. USB reset can be disabled to generate an internal reset, instead, a USB interrupt can be generated. (See Section 5. Configuration Register (CONFIG).) NOTE: USB reset is disabled when the USB module is disabled by clearing the USBEN bit of the USB Address Register (UADDR). 8.4.2.7 Registers Values After Different Resets Some registers are reset by POR or LVI reset only. Table 8-3 shows the registers or register bits which are unaffected by normal resets. Technical Data 102 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 System Integration Module (SIM) Freescale Semiconductor System Integration Module (SIM) SIM Counter Table 8-3. Registers not Affected by Normal Reset Bits Registers After Reset (except POR or LVI) After POR or LVI URSTD, LVIDIS CONFIG Unaffected 0 USBEN UADDR Unaffected 0 PULLEN UCR3 Unaffected 0 All USR0, USR1 Unaffected Indeterminate All UE0D0–UE0D7 Unaffected Indeterminate All UE1D0–UE1D7 Unaffected Indeterminate All UE2D0–UE2D7 Unaffected Indeterminate All PTA, PTB, PTC, PTD, and PTE Unaffected Indeterminate DDRA7 DDRA Unaffected 0 8.5 SIM Counter The SIM counter is used by the power-on reset module (POR) and in stop mode recovery to allow the oscillator time to stabilize before enabling the internal bus (IBUS) clocks. The SIM counter also serves as a prescalar for the computer operating properly module (COP). The SIM counter uses 12 stages for counting, followed by a 13th stage that triggers a reset of SIM counters and supplies the clock for the COP module. The SIM counter is clocked by the falling edge of OSCXCLK. 8.5.1 SIM Counter During Power-On Reset The power-on reset module (POR) detects power applied to the MCU. At power-on, the POR circuit asserts the signal PORRST. Once the SIM is initialized, it enables the oscillator to drive the bus clock state machine. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor System Integration Module (SIM) Technical Data 103 System Integration Module (SIM) 8.5.2 SIM Counter During Stop Mode Recovery The SIM counter also is used for stop mode recovery. The STOP instruction clears the SIM counter. After an interrupt, break, or reset, the SIM senses the state of the short stop recovery bit, SSREC, in the configuration register (CONFIG). If the SSREC bit is a logic 1, then the stop recovery is reduced from the normal delay of 4096 OSCXCLK cycles down to 2048 OSCXCLK cycles. This is ideal for applications using canned oscillators that do not require long startup times from stop mode. External crystal applications should use the full stop recovery time, that is, with SSREC cleared in the configuration register (CONFIG). 8.5.3 SIM Counter and Reset States External reset has no effect on the SIM counter. (See 8.7.2 Stop Mode for details.) The SIM counter is free-running after all reset states. (See 8.4.2 Active Resets from Internal Sources for counter control and internal reset recovery sequences.) 8.6 Exception Control Normal, sequential program execution can be changed in three different ways: • Interrupts – Maskable hardware CPU interrupts – Non-maskable software interrupt instruction (SWI) • Reset • Break interrupts 8.6.1 Interrupts An interrupt temporarily changes the sequence of program execution to respond to a particular event. Figure 8-8 flow charts the handling of system interrupts. Technical Data 104 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 System Integration Module (SIM) Freescale Semiconductor System Integration Module (SIM) Exception Control FROM RESET BREAK INTERRUPT ? NO YES YES BITSET? SET? IIBIT NO IRQ INTERRUPT ? NO YES USB INTERRUPT ? NO YES OTHER INTERRUPTS ? NO YES STACK CPU REGISTERS SET I BIT LOAD PC WITH INTERRUPT VECTOR FETCH NEXT INSTRUCTION SWI INSTRUCTION ? YES NO RTI INSTRUCTION ? YES UNSTACK CPU REGISTERS NO EXECUTE INSTRUCTION Figure 8-8. Interrupt Processing MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor System Integration Module (SIM) Technical Data 105 System Integration Module (SIM) Interrupts are latched and arbitration is performed in the SIM at the start of interrupt processing. The arbitration result is a constant that the CPU uses to determine which vector to fetch. Once an interrupt is latched by the SIM, no other interrupt can take precedence, regardless of priority, until the latched interrupt is serviced or the I bit is cleared. At the beginning of an interrupt, the CPU saves the CPU register contents on the stack and sets the interrupt mask (I bit) to prevent additional interrupts. At the end of an interrupt, the RTI instruction recovers the CPU register contents from the stack so that normal processing can resume. Figure 8-9 shows interrupt entry timing. Figure 8-10 shows interrupt recovery timing. MODULE INTERRUPT I BIT IAB IDB DUMMY SP DUMMY SP – 1 SP – 2 PC – 1[7:0] PC – 1[15:8] SP – 3 X SP – 4 A VECT H CCR VECT L V DATA H START ADDR V DATA L OPCODE R/W Figure 8-9. Interrupt Entry MODULE INTERRUPT I BIT IAB IDB SP – 4 SP – 3 CCR SP – 2 A SP – 1 X SP PC PC –1 [15:8] PC – 1[7:0] PC + 1 OPCODE OPERAND R/W Figure 8-10. Interrupt Recovery Technical Data 106 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 System Integration Module (SIM) Freescale Semiconductor System Integration Module (SIM) Exception Control 8.6.1.1 Hardware Interrupts A hardware interrupt does not stop the current instruction. Processing of a hardware interrupt begins after completion of the current instruction. When the current instruction is complete, the SIM checks all pending hardware interrupts. If interrupts are not masked (I bit clear in the condition code register) and if the corresponding interrupt enable bit is set, the SIM proceeds with interrupt processing; otherwise, the next instruction is fetched and executed. If more than one interrupt is pending at the end of an instruction execution, the highest priority interrupt is serviced first. Figure 8-11 demonstrates what happens when two interrupts are pending. If an interrupt is pending upon exit from the original interrupt service routine, the pending interrupt is serviced before the LDA instruction is executed. CLI BACKGROUND ROUTINE LDA #$FF INT1 PSHH INT1 INTERRUPT SERVICE ROUTINE PULH RTI INT2 PSHH INT2 INTERRUPT SERVICE ROUTINE PULH RTI Figure 8-11. Interrupt Recognition Example The LDA opcode is prefetched by both the INT1 and INT2 RTI instructions. However, in the case of the INT1 RTI prefetch, this is a redundant operation. NOTE: To maintain compatibility with the M6805 Family, the H register is not pushed on the stack during interrupt entry. If the interrupt service routine modifies the H register or uses the indexed addressing mode, software should save the H register and then restore it prior to exiting the routine. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor System Integration Module (SIM) Technical Data 107 System Integration Module (SIM) 8.6.1.2 SWI Instruction The SWI instruction is a non-maskable instruction that causes an interrupt regardless of the state of the interrupt mask (I bit) in the condition code register. NOTE: A software interrupt pushes PC onto the stack. A software interrupt does not push PC–1, as a hardware interrupt does. 8.6.2 Interrupt Status Registers The flags in the interrupt status registers identify maskable interrupt sources. Table 8-4 summarizes the interrupt sources and the interrupt status register flags that they set. The interrupt status registers can be useful for debugging. Table 8-4. Interrupt Sources Source Mask(1) Flags SWI Instruction INT Register Flag Priority(2) Vector Address — 0 $FFFC–$FFFD IF2 1 $FFFA–$FFFB USB Reset Interrupt RSTF URSTD USB Endpoint 0 Transmit TXD0F TXD0IE USB Endpoint 0 Receive RXD0F RXD0IE USB Endpoint 1 Transmit TXD1F TXD1IE USB Endpoint 2 Transmit TXD2F TXD2IE USB Endpoint 2 Receive RXD2F RXD2IE USB End of Packet EOPF EOPIE RESUMF — IRQF PTE4IF IMASK IF1 2 $FFF8–$FFF9 TIM Channel 0 CH0F CH0IE IF3 3 $FFF6–$FFF7 TIM Channel 1 CH1F CH1IE IF4 4 $FFF4–$FFF5 TOF TOIE IF5 5 $FFF2–$FFF3 KEYF IMASKK IF6 6 $FFF0–$FFF1 USB Resume Interrupt IRQ Interrupt (IRQ, PTE4) TIM Overflow Keyboard Interrupt 1. The I bit in the condition code register is a global mask for all interrupt sources except the SWI instruction. 2. 0 = highest priority Technical Data 108 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 System Integration Module (SIM) Freescale Semiconductor System Integration Module (SIM) Exception Control 8.6.2.1 Interrupt Status Register 1 Address: $FE04 Bit 7 6 5 4 3 2 1 Bit 0 Read: IF6 IF5 IF4 IF3 IF2 IF1 0 0 Write: R R R R R R R R Reset: 0 0 0 0 0 0 0 0 R = Reserved Figure 8-12. Interrupt Status Register 1 (INT1) IF6–IF1 — Interrupt Flags 1–6 These flags indicate the presence of interrupt requests from the sources shown in Table 8-4. 1 = Interrupt request present 0 = No interrupt request present Bit 0 and Bit 1 — Always read 0 8.6.3 Reset All reset sources always have equal and highest priority and cannot be arbitrated. 8.6.4 Break Interrupts The break module can stop normal program flow at a softwareprogrammable break point by asserting its break interrupt output. (See Section 17. Break Module (BREAK).) The SIM puts the CPU into the break state by forcing it to the SWI vector location. Refer to the break interrupt subsection of each module to see how each module is affected by the break state. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor System Integration Module (SIM) Technical Data 109 System Integration Module (SIM) 8.6.5 Status Flag Protection in Break Mode The SIM controls whether status flags contained in other modules can be cleared during break mode. The user can select whether flags are protected from being cleared by properly initializing the break clear flag enable bit (BCFE) in the break flag control register (BFCR). Protecting flags in break mode ensures that set flags will not be cleared while in break mode. This protection allows registers to be freely read and written during break mode without losing status flag information. Setting the BCFE bit enables the clearing mechanisms. Once cleared in break mode, a flag remains cleared even when break mode is exited. Status flags with a 2-step clearing mechanism — for example, a read of one register followed by the read or write of another — are protected, even when the first step is accomplished prior to entering break mode. Upon leaving break mode, execution of the second step will clear the flag as normal. 8.7 Low-Power Modes Executing the WAIT or STOP instruction puts the MCU in a low-powerconsumption mode for standby situations. The SIM holds the CPU in a non-clocked state. The operation of each of these modes is described here. Both STOP and WAIT clear the interrupt mask (I) in the condition code register, allowing interrupts to occur. 8.7.1 Wait Mode In wait mode, the CPU clocks are inactive while the peripheral clocks continue to run. Figure 8-13 shows the timing for wait mode entry. A module that is active during wait mode can wake up the CPU with an interrupt if the interrupt is enabled. Stacking for the interrupt begins one cycle after the WAIT instruction during which the interrupt occurred. In wait mode, the CPU clocks are inactive. Refer to the wait mode subsection of each module to see if the module is active or inactive in wait mode. Some modules can be programmed to be active in wait mode. Technical Data 110 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 System Integration Module (SIM) Freescale Semiconductor System Integration Module (SIM) Low-Power Modes Wait mode can also be exited by a reset or break. A break interrupt during wait mode sets the SIM break stop/wait bit, SBSW, in the break status register (BSR). If the COP disable bit, COPD, in the mask option register is logic 0, then the computer operating properly module (COP) is enabled and remains active in wait mode. WAIT ADDR IAB WAIT ADDR + 1 PREVIOUS DATA IDB SAME NEXT OPCODE SAME SAME SAME R/W NOTE: Previous data can be operand data or the WAIT opcode, depending on the last instruction. Figure 8-13. Wait Mode Entry Timing Figure 8-14 and Figure 8-15 show the timing for WAIT recovery. IAB IDB $6E0B $A6 $A6 $6E0C $A6 $01 $00FF $00FE $0B $00FD $00FC $6E EXITSTOPWAIT NOTE: EXITSTOPWAIT = RST pin or CPU interrupt or break interrupt Figure 8-14. Wait Recovery from Interrupt or Break 32 CYCLES $6E0B IAB IDB $A6 $A6 32 CYCLES RST VCT H RST VCT L $A6 RST OSCXCLK Figure 8-15. Wait Recovery from Internal Reset MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor System Integration Module (SIM) Technical Data 111 System Integration Module (SIM) 8.7.2 Stop Mode In stop mode, the SIM counter is reset and the system clocks are disabled. An interrupt request from a module can cause an exit from stop mode. Stacking for interrupts begins after the selected stop recovery time has elapsed. Reset or break also causes an exit from stop mode. The SIM disables the oscillator signals (OSCOUT and OSCXCLK) in stop mode, stopping the CPU and peripherals. Stop recovery time is selectable using the SSREC bit in the configuration register (CONFIG). If SSREC is set, stop recovery is reduced from the normal delay of 4096 OSCXCLK cycles down to 2048. This is ideal for applications using canned oscillators that do not require long startup times from stop mode. NOTE: External crystal applications should use the full stop recovery time by clearing the SSREC bit. A break interrupt during stop mode sets the SIM break stop/wait bit (SBSW) in the break status register (BSR). The SIM counter is held in reset from the execution of the STOP instruction until the beginning of stop recovery. It is then used to time the recovery period. Figure 8-16 shows stop mode entry timing. NOTE: To minimize stop current, all pins configured as inputs should be driven to a logic 1 or logic 0. CPUSTOP IAB IDB STOP ADDR STOP ADDR + 1 PREVIOUS DATA SAME NEXT OPCODE SAME SAME SAME R/W NOTE: Previous data can be operand data or the STOP opcode, depending on the last instruction. Figure 8-16. Stop Mode Entry Timing Technical Data 112 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 System Integration Module (SIM) Freescale Semiconductor System Integration Module (SIM) SIM Registers STOP RECOVERY PERIOD OSCXCLK INT/BREAK IAB STOP +1 STOP + 2 STOP + 2 SP SP – 1 SP – 2 SP – 3 Figure 8-17. Stop Mode Recovery from Interrupt or Break 8.8 SIM Registers The SIM has two break registers and one reset register. 8.8.1 Break Status Register The break status register contains a flag to indicate that a break caused an exit from stop or wait mode. Address: $FE00 Bit 7 6 5 4 3 2 R R R R R R Read: 1 Bit 0 SBSW R Write: Note 1 Reset: 0 Note 1. Writing a logic 0 clears SBSW. R = Reserved Figure 8-18. Break Status Register (BSR) SBSW — SIM Break Stop/Wait This status bit is useful in applications requiring a return to wait or stop mode after exiting from a break interrupt. Clear SBSW by writing a logic 0 to it. Reset clears SBSW. 1 = Stop mode or wait mode was exited by break interrupt 0 = Stop mode or wait mode was not exited by break interrupt MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor System Integration Module (SIM) Technical Data 113 System Integration Module (SIM) SBSW can be read within the break state SWI routine. The user can modify the return address on the stack by subtracting one from it. The following code is an example of this. Writing 0 to the SBSW bit clears it. This code works if the H register has been pushed onto the stack in the break service routine software. This code should be executed at the end of the break service routine software. HIBYTE EQU 5 LOBYTE EQU 6 ; If not SBSW, do RTI BRCLR SBSW,BSR, RETURN ; See if wait mode or stop mode was exited ; by break. TST LOBYTE,SP ; If RETURNLO is not zero, BNE DOLO ; then just decrement low byte. DEC HIBYTE,SP ; Else deal with high byte, too. DOLO DEC LOBYTE,SP ; Point to WAIT/STOP opcode. RETURN PULH RTI ; Restore H register. 8.8.2 Reset Status Register This register contains seven flags that show the source of the last reset. All flag bits are cleared automatically following a read of the register. The register is initialized on power-up as shown with the POR bit set and all other bits cleared. However, during a POR or any other internal reset, the RST pin is pulled low. After the pin is released, it will be sampled 32 XCLK cycles later. If the pin is not above a VIH at that time, then the PIN bit in the RSR may be set in addition to whatever other bits are set. Technical Data 114 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 System Integration Module (SIM) Freescale Semiconductor System Integration Module (SIM) SIM Registers Address: Read: $FE01 Bit 7 6 5 4 3 2 1 Bit 0 POR PIN COP ILOP ILAD USB LVI 0 1 0 0 0 0 0 0 0 Write: POR: = Unimplemented Figure 8-19. Reset Status Register (RSR) POR — Power-On Reset Bit 1 = A POR has occurred 0 = Read of RSR PIN — External Reset Bit 1 = An external reset has occurred since the last read of the RSR 0 = Read of RSR COP — Computer Operating Properly Reset Bit 1 = A COP reset has occurred since the last read of the RSR 0 = POR or read of RSR ILOP — Illegal Opcode Reset Bit An illegal opcode reset has occurred since the last read of the RSR 0 = POR or read of RSR ILAD — Illegal Address Reset Bit (opcode fetches only) 1 = An illegal address reset has occurred since the last read of the RSR 0 = POR or read of RSR USB — Universal Serial Bus Reset Bit 1 = Last reset caused by the USB module 0 = POR or read of RSR LVI — Low voltage inhibit Reset Bit 1 = A LVI reset has occurred since the last read of PSR 0 = POR or read of RSR MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor System Integration Module (SIM) Technical Data 115 System Integration Module (SIM) 8.8.3 Break Flag Control Register The break control register contains a bit that enables software to clear status bits while the MCU is in a break state. Address: $FE03 Bit 7 6 5 4 3 2 1 Bit 0 BCFE R R R R R R R Read: Write: POR: 0 R = Reserved Figure 8-20. Break Flag Control Register (BFCR) BCFE — Break Clear Flag Enable Bit This read/write bit enables software to clear status bits by accessing status registers while the MCU is in a break state. To clear status bits during the break state, the BCFE bit must be set. 1 = Status bits clearable during break 0 = Status bits not clearable during break Technical Data 116 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 System Integration Module (SIM) Freescale Semiconductor Technical Data — MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 Section 9. Universal Serial Bus Module (USB) 9.1 Contents 9.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118 9.3 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119 9.4 Pin Name Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120 9.5 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .124 9.5.1 USB Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 9.5.1.1 Sync Pattern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126 9.5.1.2 Packet Identifier Field . . . . . . . . . . . . . . . . . . . . . . . . . . 127 9.5.1.3 Address Field (ADDR) . . . . . . . . . . . . . . . . . . . . . . . . . . 128 9.5.1.4 Endpoint Field (ENDP). . . . . . . . . . . . . . . . . . . . . . . . . . 128 9.5.1.5 Cyclic Redundancy Check (CRC) . . . . . . . . . . . . . . . . . 128 9.5.1.6 End-of-Packet (EOP) . . . . . . . . . . . . . . . . . . . . . . . . . . .128 9.5.2 Reset Signaling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129 9.5.3 Suspend . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130 9.5.4 Resume After Suspend . . . . . . . . . . . . . . . . . . . . . . . . . . . 131 9.5.4.1 Host Initiated Resume . . . . . . . . . . . . . . . . . . . . . . . . . . 131 9.5.4.2 USB Reset Signalling. . . . . . . . . . . . . . . . . . . . . . . . . . .131 9.5.4.3 Remote Wakeup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .131 9.5.5 Low-Speed Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132 9.6 Clock Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132 9.7 Hardware Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 9.7.1 Voltage Regulator. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 9.7.2 USB Transceiver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 9.7.2.1 Output Driver Characteristics . . . . . . . . . . . . . . . . . . . . . 134 9.7.2.2 Low Speed (1.5 Mbps) Driver Characteristics . . . . . . . . 134 9.7.2.3 Receiver Data Jitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135 9.7.2.4 Data Source Jitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135 9.7.2.5 Data Signal Rise and Fall Time . . . . . . . . . . . . . . . . . . . 136 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Universal Serial Bus Module (USB) Technical Data 117 Universal Serial Bus Module (USB) 9.7.3 USB Control Logic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137 9.8 I/O Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137 9.8.1 USB Address Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138 9.8.2 USB Interrupt Register 0 . . . . . . . . . . . . . . . . . . . . . . . . . . 139 9.8.3 USB Interrupt Register 1 . . . . . . . . . . . . . . . . . . . . . . . . . . 141 9.8.4 USB Interrupt Register 2 . . . . . . . . . . . . . . . . . . . . . . . . . . 144 9.8.5 USB Control Register 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . 145 9.8.6 USB Control Register 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . 146 9.8.7 USB Control Register 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . 147 9.8.8 USB Control Register 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . 149 9.8.9 USB Control Register 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . 151 9.8.10 USB Status Register 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152 9.8.11 USB Status Register 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153 9.8.12 USB Endpoint 0 Data Registers . . . . . . . . . . . . . . . . . . . . . 154 9.8.13 USB Endpoint 1 Data Registers . . . . . . . . . . . . . . . . . . . . . 155 9.8.14 USB Endpoint 2 Data Registers . . . . . . . . . . . . . . . . . . . . . 156 9.9 USB Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157 9.9.1 USB End-of-Transaction Interrupt . . . . . . . . . . . . . . . . . . . 157 9.9.1.1 Receive Control Endpoint 0 . . . . . . . . . . . . . . . . . . . . . . 158 9.9.1.2 Transmit Control Endpoint 0 . . . . . . . . . . . . . . . . . . . . . 160 9.9.1.3 Transmit Endpoint 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161 9.9.1.4 Transmit Endpoint 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162 9.9.1.5 Receive Endpoint 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162 9.9.2 Resume Interrupt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162 9.9.3 End-of-Packet Interrupt . . . . . . . . . . . . . . . . . . . . . . . . . . . 162 9.2 Introduction This section describes the universal serial bus (USB) module. The USB module is designed to serve as a low-speed (LS) USB device per the Universal Serial Bus Specification Rev 1.1. Control and interrupt data transfers are supported. Endpoint 0 functions as a transmit/receive control endpoint; endpoint 1 functions as interrupt transmit endpoint; endpoint 2 functions as interrupt transmit or receive endpoint. Technical Data 118 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Universal Serial Bus Module (USB) Freescale Semiconductor Universal Serial Bus Module (USB) Features 9.3 Features Features of the USB module include: • Full Universal Serial Bus Specification 1.1 low-speed functions • 1.5 Mbps data rate • On-chip 3.3V regulator • Endpoint 0 with 8-byte transmit buffer and 8-byte receive buffer • Endpoint 1 with 8-byte transmit buffer • Endpoint 2 with 8-byte transmit buffer and 8-byte receive buffer • USB data control logic: – Control endpoint 0 and interrupt endpoints 1 and 2 – Packet decoding/generation – CRC generation and checking – NRZI (Non-Return-to Zero Inserted) encoding/decoding – Bit-stuffing • USB reset options: – Internal MCU reset generation – CPU interrupt request generation • Suspend and resume operations, with remote wakeup support • USB-generated interrupts: – Transaction interrupt driven – Resume interrupt – End-of-packet interrupt – USB reset • STALL, NAK, and ACK handshake generation MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Universal Serial Bus Module (USB) Technical Data 119 Universal Serial Bus Module (USB) 9.4 Pin Name Conventions The USB share two I/O pins with two port E I/O pins. The full name of the USB I/O pin is listed in Table 9-1. The generic pin name appear in the text that follows. Table 9-1. USB Module Pin Name Conventions Addr. $0018 $0019 $001A Register Name USB Generic Pin Names: D+ D– Full USB Pin Names: PTE3/D+ PTE4/D– Bit 7 6 5 4 3 2 1 Bit 0 0 0 0 0 0 0 0 RSTFR TXD2FR RXD2FR 0 0 0 0 0 0 0 T2SEQ STALL2 TX2E RX2E TP2SIZ3 TP2SIZ2 TP2SIZ1 TP2SIZ0 0 0 0 0 0 0 0 0 TX1ST 0 OSTALL0 ISTALL0 Read: 0 USB Interrupt Register 2 Write: EOPFR (UIR2) Reset: 0 Read: USB Control Register 2 Write: (UCR2) Reset: Read: USB Control Register 3 Write: (UCR3) Reset: TX1STR TXD1FR RESUMFR TXD0FR 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Read: UE0R07 USB Endpoint 0 Data Register 0 Write: UE0T07 (UE0D0) Reset: UE0R06 UE0R05 UE0T06 UE0T05 Read: UE0R17 USB Endpoint 0 Data Register 1 Write: UE0T17 (UE0D1) Reset: UE0R16 UE0R15 UE0R14 UE0T16 UE0T15 UE0T14 RXD0FR PULLEN ENABLE2 ENABLE1 0* 0 0 FUSBO FDP FDM 0 0 0 0 UE0R04 UE0R03 UE0R02 UE0R01 UE0R00 UE0T04 UE0T03 UE0T02 UE0T01 UE0T00 UE0R13 UE0R12 UE0R11 UE0R10 UE0T13 UE0T12 UE0T11 UE0T10 * PULLEN bit is reset by POR or LVI reset only. $001B $0020 $0021 Read: USB Control Register 4 Write: (UCR4) Reset: Unaffected by reset Unaffected by reset = Unimplemented U = Unaffected by reset Figure 9-1. USB I/O Register Summary (Sheet 1 of 4) Technical Data 120 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Universal Serial Bus Module (USB) Freescale Semiconductor Universal Serial Bus Module (USB) Pin Name Conventions Addr. Register Name $0022 $0023 $0024 $0025 $0026 $0027 $0028 $0029 $002A $002B Bit 7 6 5 4 3 2 1 Bit 0 Read: UE0R27 USB Endpoint 0 Data Register 2 Write: UE0T27 (UE0D2) Reset: UE0R26 UE0R25 UE0R24 UE0R23 UE0R22 UE0R21 UE0R20 UE0T26 UE0T25 UE0T24 UE0T23 UE0T22 UE0T21 UE0T20 Read: UE0R37 USB Endpoint 0 Data Register 3 Write: UE0T37 (UE0D3) Reset: UE0R36 UE0R35 UE0R34 UE0R33 UE0R32 UE0R31 UE0R30 UE0T36 UE0T35 UE0T34 UE0T33 UE0T32 UE0T31 UE0T30 Read: UE0R47 USB Endpoint 0 Data Register 4 Write: UE0T47 (UE0D4) Reset: UE0R46 UE0R45 UE0R44 UE0R43 UE0R42 UE0R41 UE0R40 UE0T46 UE0T45 UE0T44 UE0T43 UE0T42 UE0T41 UE0T40 Read: UE0R57 USB Endpoint 0 Data Register 5 Write: UE0T57 (UE0D5) Reset: UE0R56 UE0R55 UE0R54 UE0R53 UE0R52 UE0R51 UE0R50 UE0T56 UE0T55 UE0T54 UE0T53 UE0T52 UE0T51 UE0T50 Read: UE0R67 USB Endpoint 0 Data Register 6 Write: UE0T67 (UE0D6) Reset: UE0R66 UE0R65 UE0R64 UE0R63 UE0R62 UE0R61 UE0R60 UE0T66 UE0T65 UE0T64 UE0T63 UE0T62 UE0T61 UE0T60 Read: UE0R77 USB Endpoint 0 Data Register 7 Write: UE0T77 (UE0D7) Reset: UE0R76 UE0R75 UE0R74 UE0R73 UE0R72 UE0R71 UE0R70 UE0T76 UE0T75 UE0T74 UE0T73 UE0T72 UE0T71 UE0T70 UE1T02 UE1T01 UE1T00 UE1T12 UE1T11 UE1T10 UE1T22 UE1T21 UE1T20 UE1T32 UE1T31 UE1T30 Unaffected by reset Unaffected by reset Unaffected by reset Unaffected by reset Unaffected by reset Unaffected by reset Read: USB Endpoint 1 Data Register 0 Write: UE1T07 (UE1D0) Reset: UE1T06 Read: USB Endpoint 1 Data Register 1 Write: UE1T17 (UE1D1) Reset: UE1T16 Read: USB Endpoint 1 Data Register 2 Write: UE1T27 (UE1D2) Reset: UE1T26 Read: USB Endpoint 1 Data Register 3 Write: UE1T37 (UE1D3) Reset: UE1T36 UE1T05 UE1T04 UE1T03 Unaffected by reset UE1T15 UE1T14 UE1T13 Unaffected by reset UE1T25 UE1T24 UE1T23 Unaffected by reset UE1T35 UE1T34 UE1T33 Unaffected by reset = Unimplemented U = Unaffected by reset Figure 9-1. USB I/O Register Summary (Sheet 2 of 4) MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Universal Serial Bus Module (USB) Technical Data 121 Universal Serial Bus Module (USB) Addr. Register Name $002C $002D $002E $002F $0030 $0031 $0032 $0033 $0034 $0035 Bit 7 6 5 4 3 2 1 Bit 0 Read: USB Endpoint 1 Data Register 4 Write: UE1T47 (UE1D4) Reset: UE1T46 UE1T45 UE1T44 UE1T43 UE1T42 UE1T41 UE1T40 Read: USB Endpoint 1 Data Register5 Write: UE1T57 (UE1D5) Reset: UE1T56 UE1T52 UE1T51 UE1T50 Read: USB Endpoint 1 Data Register 6 Write: UE1T67 (UE1D6) Reset: UE1T66 UE1T62 UE1T61 UE1T60 Read: USB Endpoint 1 Data Register 7 Write: UE1T77 (UE1D7) Reset: UE1T76 UE1T72 UE1T71 UE1T70 Unaffected by reset UE1T55 UE1T54 UE1T53 Unaffected by reset UE1T65 UE1T64 UE1T63 Unaffected by reset UE1T75 UE1T74 UE1T73 Unaffected by reset Read: UE2R07 USB Endpoint 2 Data Register 0 Write: UE2T07 (UE2D0) Reset: UE2R06 UE2R05 UE2R04 UE2R03 UE2R02 UE2R01 UE2R00 UE2T06 UE2T05 UE2T04 UE2T03 UE2T02 UE2T01 UE2T00 Read: UE2R17 USB Endpoint 2 Data Register 1 Write: UE2T17 (UE2D1) Reset: UE2R16 UE2R15 UE2R14 UE2R13 UE2R12 UE2R11 UE2R10 UE2T16 UE2T15 UE2T14 UE2T13 UE2T12 UE2T11 UE2T10 Read: UE2R27 USB Endpoint 2 Data Register 2 Write: UE2T27 (UE2D2) Reset: UE2R26 UE2R25 UE2R24 UE2R23 UE2R22 UE2R21 UE2R20 UE2T26 UE2T25 UE2T24 UE2T23 UE2T22 UE2T21 UE2T20 Read: UE2R37 USB Endpoint 2 Data Register 3 Write: UE2T37 (UE2D3) Reset: UE2R36 UE2R35 UE2R34 UE2R33 UE2R32 UE2R31 UE2R30 UE2T36 UE2T35 UE2T34 UE2T33 UE2T32 UE2T31 UE2T30 Read: UE2R47 USB Endpoint 2 Data Register 4 Write: UE2T47 (UE2D4) Reset: UE2R46 UE2R45 UE2R44 UE2R43 UE2R42 UE2R41 UE2R40 UE2T46 UE2T45 UE2T44 UE2T43 UE2T42 UE2T41 UE2T40 Read: UE2R57 USB Endpoint 2 Data Register 5 Write: UE2T57 (UE2D5) Reset: UE2R56 UE2R55 UE2R54 UE2R53 UE2R52 UE2R51 UE2R50 UE2T56 UE2T55 UE2T54 UE2T53 UE2T52 UE2T51 UE2T50 Unaffected by reset Unaffected by reset Unaffected by reset Unaffected by reset Unaffected by reset Unaffected by reset = Unimplemented U = Unaffected by reset Figure 9-1. USB I/O Register Summary (Sheet 3 of 4) Technical Data 122 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Universal Serial Bus Module (USB) Freescale Semiconductor Universal Serial Bus Module (USB) Pin Name Conventions Addr. Register Name $0036 $0037 $0038 Bit 7 6 5 4 3 2 1 Bit 0 Read: UE2R67 USB Endpoint 2 Data Register 6 Write: UE2T67 (UE2D6) Reset: UE2R66 UE2R65 UE2R64 UE2R63 UE2R62 UE2R61 UE2R60 UE2T66 UE2T65 UE2T64 UE2T63 UE2T62 UE2T61 UE2T60 Read: UE2R77 USB Endpoint 2 Data Register 7 Write: UE2T77 (UE2D7) Reset: UE2R76 UE2R75 UE2R74 UE2R73 UE2R72 UE2R71 UE2R70 UE2T76 UE2T75 UE2T74 UE2T73 UE2T72 UE2T71 UE2T70 USB Address Register Read: USBEN (UADDR) Write: Unaffected by reset Unaffected by reset UADD6 UADD5 UADD4 UADD3 UADD2 UADD1 UADD0 0* 0 0 0 0 0 0 0 EOPIE SUSPND TXD2IE RXD2IE TXD1IE TXD0IE RXD0IE 0 0 0 0 0 0 0 0 EOPF RSTF TXD2F RXD2F TXD1F RESUMF TXD0F RXD0F 0 0 0 0 0 0 0 0 TX0E RX0E TP0SIZ3 TP0SIZ2 TP0SIZ1 TP0SIZ0 0 0 0 0 0 TP1SIZ2 TP1SIZ1 TP1SIZ0 Reset: * USBEN bit is reset by POR or LVI reset only. $0039 USB Interrupt Register 0 Read: (UIR0) Write: Reset: $003A USB Interrupt Register 1 Read: (UIR1) Write: Reset: $003B USB Control Register 0 Read: (UCR0) Write: Reset: $003C USB Control Register 1 Read: (UCR1) Write: Reset: $003D T0SEQ 0 0 0 0 T1SEQ STALL1 TX1E 0 0 0 0 0 0 0 0 SETUP 0 0 RP0SIZ3 RP0SIZ2 RP0SIZ1 RP0SIZ0 USB Status Register 0 Read: R0SEQ (USR0) Write: Reset: $003E FRESUM TP1SIZ3 Unaffected by reset USB Status Register 1 Read: R2SEQ (USR1) Write: Reset: 0 U TXACK TXNAK TXSTL RP2SIZ3 RP2SIZ2 RP2SIZ1 RP2SIZ0 0 0 0 U U U U = Unimplemented U = Unaffected by reset Figure 9-1. USB I/O Register Summary (Sheet 4 of 4) MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Universal Serial Bus Module (USB) Technical Data 123 Universal Serial Bus Module (USB) 9.5 Functional Description Figure 9-2 shows the block diagram of the USB module. The USB module manages communications between the host and the USB function. The module is partitioned into three functional blocks. These blocks consist of a dual-function transceiver, the USB control logic, and the endpoint registers. The blocks are further detailed later in this section (see 9.7 Hardware Description). USB VPIN CONTROL VMIN LOGIC TRANSCEIVER RCV D+ D– USB UPSTREAM PORT VPOUT VMOUT CPU BUS USB REGISTERS Figure 9-2. USB Block Diagram Technical Data 124 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Universal Serial Bus Module (USB) Freescale Semiconductor Universal Serial Bus Module (USB) Functional Description 9.5.1 USB Protocol Figure 9-3 shows the various transaction types supported by the USB module. The transactions are portrayed as error free. The effect of errors in the data flow are discussed later. ENDPOINT 0 TRANSACTIONS: Control Write SETUP DATA0 ACK OUT DATA0 OUT ACK DATA1 ACK OUT DATA0/1 IN DATA1 ACK ACK Control Read SETUP DATA0 ACK IN DATA0 IN ACK DATA1 ACK IN DATA0/1 OUT DATA1 ACK ACK No-Data Control SETUP DATA0 ACK IN ACK DATA1 ENDPOINTS 1 & 2 TRANSACTIONS: KEY: Interrupt IN DATA0/1 ACK Unrelated Bus Traffic Host Generated Bulk Transmit IN DATA0/1 ACK Device Generated Figure 9-3. Supported Transaction Types Per Endpoint MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Universal Serial Bus Module (USB) Technical Data 125 Universal Serial Bus Module (USB) Each USB transaction is comprised of a series of packets. The USB module supports the packet types shown in Figure 9-4. Token packets are generated by the USB host and decoded by the USB device. Data and handshake packets are both decoded and generated by the USB device, depending on the type of transaction. Token Packet: IN OUT SYNC PID PID SYNC PID PID ADDR ENDP CRC5 EOP CRC16 EOP SETUP Data Packet: DATA0 DATA1 DATA 0 – 8 Bytes Handshake Packet: ACK NAK SYNC PID PID EOP STALL Figure 9-4. Supported USB Packet Types The following sections detail each segment used to form a complete USB transaction. 9.5.1.1 Sync Pattern The NRZI bit pattern shown in Figure 9-5 is used as a synchronization pattern and is prefixed to each packet. This pattern is equivalent to a data pattern of seven 0s followed by a 1 ($80). SYNC PATTERN NRZI Data Encoding Idle PID0 PID1 Figure 9-5. Sync Pattern Technical Data 126 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Universal Serial Bus Module (USB) Freescale Semiconductor Universal Serial Bus Module (USB) Functional Description The start of a packet (SOP) is signaled by the originating port by driving the D+ and D– lines from the idle state (also referred to as the J state) to the opposite logic level (also referred to as the K state). This switch in levels represents the first bit of the sync field. Figure 9-6 shows the data signaling and voltage levels for the start of packet and the sync pattern. VOH (min.) VSE (max) VSE (min.) VOL (min.) VSS FIRST BIT OF PACKET BUS IDLE SOP END OF SYNC Figure 9-6. SOP, Sync Signaling, and Voltage Levels 9.5.1.2 Packet Identifier Field The packet identifier field is an 8-bit number comprised of the 4-bit packet identification and its complement. The field follows the sync pattern and determines the direction and type of transaction on the bus. Table 9-2 shows the packet identifier values for the supported packet types. Table 9-2. Supported Packet Identifiers Packet Identifier Value Packet Identifier Type %1001 IN Token %0001 OUT Token %1101 SETUP Token %0011 DATA0 Packet %1011 DATA1 Packet %0010 ACK Handshake %1010 NAK Handshake %1110 STALL Handshake MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Universal Serial Bus Module (USB) Technical Data 127 Universal Serial Bus Module (USB) 9.5.1.3 Address Field (ADDR) The address field is a 7-bit number that is used to select a particular USB device. This field is compared to the lower seven bits of the UADDR register to determine if a given transaction is targeting the MCU USB device. 9.5.1.4 Endpoint Field (ENDP) The endpoint field is a 4-bit number that is used to select a particular endpoint within a USB device. For the MCU, this will be a binary number between 0 and 2 inclusive. Any other value will cause the transaction to be ignored. 9.5.1.5 Cyclic Redundancy Check (CRC) Cyclic redundancy checks are used to verify the address and data stream of a USB transaction. This field is five bits wide for token packets and 16 bits wide for data packets. CRCs are generated in the transmitter and sent on the USB data lines after both the endpoint field and the data field. 9.5.1.6 End-of-Packet (EOP) The single-ended 0 (SE0) state is used to signal an end-of-packet (EOP). The single-ended 0 state is indicated by both D+ and D– being below 0.8V. EOP will be signaled by driving D+ and D– to the single-ended 0 state for two bit times followed by driving the lines to the idle state for one bit time. The transition from the single-ended 0 to the idle state defines the end of the packet. The idle state is asserted for one bit time and then both the D+ and D– output drivers are placed in their high-impedance state. The bus termination resistors hold the bus in the idle state. Figure 9-7 shows the data signaling and voltage levels for an end-of-packet transaction. Technical Data 128 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Universal Serial Bus Module (USB) Freescale Semiconductor Universal Serial Bus Module (USB) Functional Description LAST BIT OF PACKET EOP STROBE BUS DRIVEN TO IDLE STATE BUS FLOATS BUS IDLE VOH (min.) VSE (max) VSE (min.) VOL (min.) VSS Figure 9-7. EOP Transaction Voltage Levels The width of the SE0 in the EOP is about two bit times. The EOP width is measured with the same capacitive load used for maximum rise and fall times and is measured at the same level as the differential signal crossover points of the data lines. tPeriod DATA CROSSOVER LEVEL DIFFERENTIAL DATA LINES EOP WIDTH Figure 9-8. EOP Width Timing 9.5.2 Reset Signaling The USB module will detect a reset signaled on the bus by the presence of an extended SE0 at the USB data pins of a device. The MCU seeing a single-ended 0 on its USB data inputs for more than 8µs treats that signal as a reset. A USB sourced reset will hold the MCU in reset for the duration of the reset on the USB bus. The USB bit in the reset status register (RSR) will be set after the internal reset is removed. Refer to 8.8.2 Reset Status Register for more detail. The MCU’s reset recovery sequence is detailed in Section 8. System Integration Module (SIM). MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Universal Serial Bus Module (USB) Technical Data 129 Universal Serial Bus Module (USB) The reset flag bit (RSTF) in the USB interrupt register 1 (UIR1) also will be set after the internal reset is removed. Refer to 9.8.3 USB Interrupt Register 1 for more detail. After a reset is removed, the device will be in the default, but not yet addressed or configured state (refer to Section 9.1 USB Device States of the Universal Serial Bus Specification Rev. 1.1). The device must be able to accept a device address via a SET_ADDRESS command (refer to Section 9.4 Standard Device Request in the Universal Serial Bus Specification Rev. 1.1) no later than 10 ms after the reset is removed. Reset can wake a device from the suspended mode. NOTE: USB Reset can be configured not to generate a reset signal to the CPU by setting the URSTD bit of the configuration register (see Section 5. Configuration Register (CONFIG)). When a USB reset is detected, the CPU generates an USB interrupt. 9.5.3 Suspend The MCU supports suspend mode for low power. Suspend mode should be entered when the USB data lines are in the idle state for more than 3ms. Entry into suspend mode is controlled by the SUSPND bit in the USB interrupt register. Any low-speed bus activity should keep the device out of the suspend state. Low-speed devices are kept awake by periodic low-speed EOP signals from the host. This is referred to as low speed keep alive (refer to Section 11.8.4.1 Low-Speed Keep-alive in the Universal Serial Bus Specification Rev. 1.1). Firmware should monitor the EOPF flag and enter suspend mode by setting the SUSPND bit if an EOP is not detected for 3ms. Per the USB specification, the bus powered USB system is required to draw less than 500µA from the VDD supply when in the suspend state. This includes the current supplied by the voltage regulator to the 1.5kΩ to ground termination resistors placed at the host end of the USB bus. This low-current requirement means that firmware is responsible for entering stop mode once the USB module has been placed in the suspend state. Technical Data 130 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Universal Serial Bus Module (USB) Freescale Semiconductor Universal Serial Bus Module (USB) Functional Description 9.5.4 Resume After Suspend The MCU can be activated from the suspend state by normal bus activity, a USB reset signal, or by a forced resume driven from the MCU. 9.5.4.1 Host Initiated Resume The host signals resume by initiating resume signalling (K state) for at least 20ms followed by a standard low-speed EOP signal. This 20ms ensures that all devices in the USB network are awakened. After resuming the bus, the host must begin sending bus traffic within 37ms to prevent the device from re-entering suspend mode. 9.5.4.2 USB Reset Signalling Reset can wake a device from the suspended mode. 9.5.4.3 Remote Wakeup The MCU also supports the remote wakeup feature. The firmware has the ability to exit suspend mode by signaling a resume state to the upstream host or hub. A non-idle state (K state) on the USB data lines is accomplished by asserting the FRESUM bit in the UCR1 register. When using the remote wakeup capability, the firmware must wait for at least 5ms after the bus is in the idle state before sending the remote wakeup resume signaling. This allows the upstream devices to get into their suspend state and prepare for propagating resume signaling. The FRESUM bit should be asserted to cause the resume state on the USB data lines for at least 10ms, but not more than 15ms. Note that the resume signalling is controlled by the FRESUM bit and meeting the timing specifications is dependent on the firmware. When FRESUM is cleared by firmware, the data lines will return to their high-impedance state. Refer to the register definitions (see 9.8.6 USB Control Register 1) for more information about how the force resume (FRESUM) bit can be used to initiate the remote wakeup feature. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Universal Serial Bus Module (USB) Technical Data 131 Universal Serial Bus Module (USB) 9.5.5 Low-Speed Device Low-speed devices are configured by the position of a pull-up resistor on the USB D– pin of the MCU. Low-speed devices are terminated as shown in Figure 9-9 with the pull-up on the D– line. VREG (3.3V) MCU 1.5 kΩ D+ USB LOW-SPEED CABLE D– Figure 9-9. External Low-Speed Device Configuration For low-speed transmissions, the transmitter’s EOP width must be between 1.25µs and 1.50µs. These ranges include timing variations due to differential buffer delay and rise/fall time mismatches and to noise and other random effects. A low-speed receiver must accept a 670ns SE0 followed by a J transition as a valid EOP. An SE0 shorter than 330ns or an SE0 not followed by a J transition are rejected as an EOP. Any SE0 that is 8µs or longer is automatically a reset. 9.6 Clock Requirements The low-speed data rate is nominally 1.5 Mbps. The OSCXCLK signal driven by the oscillator circuits is the clock source for the USB module and requires that a 6-MHz oscillator circuit be connected to the OSC1 and OSC2 pins. The permitted frequency tolerance for low-speed functions is approximately ±1.5% (15,000 ppm). This tolerance includes inaccuracies from all sources: initial frequency accuracy, crystal capacitive loading, supply voltage on the oscillator, temperature, and aging. The jitter in the low-speed data rate must be less than 10ns. Technical Data 132 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Universal Serial Bus Module (USB) Freescale Semiconductor Universal Serial Bus Module (USB) Hardware Description 9.7 Hardware Description The USB module as previously shown in Figure 9-2 contains three functional blocks: the low-speed USB transceiver, the USB control logic, and the USB registers. The following details the function of the regulator, transceiver, and control logic. See 9.8 I/O Registers for details of register settings. 9.7.1 Voltage Regulator The USB data lines are required by the USB specification to have an output voltage between 2.8V and 3.6V. The data lines also are required to have an external 1.5kΩ pull-up resistor connected between a data line and a voltage source between 3.0V and 3.6V. Figure 9-10 shows the worst case electrical connection for the voltage regulator. 4.0V – 5.5V 3.3V REGULATOR USB DATA LINES R1 LOW-SPEED TRANSCEIVER HOST OR HUB D+ USB CABLE D– R1 = 1.5kΩ ±5% R2 = 15kΩ ±5% R2 R2 Figure 9-10. Regulator Electrical Connections 9.7.2 USB Transceiver The USB transceiver provides the physical interface to the USB D+ and D– data lines. The transceiver is composed of two parts: an output drive circuit and a receiver. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Universal Serial Bus Module (USB) Technical Data 133 Universal Serial Bus Module (USB) 9.7.2.1 Output Driver Characteristics The USB transceiver uses a differential output driver to drive the USB data signal onto the USB cable. The static output swing of the driver in its low state is below the VOL of 0.3V with a 1.5kΩ load to 3.6V and in its high state is above the VOH of 2.8V with a 15kΩ load to ground. The output swings between the differential high and low state are well balanced to minimize signal skew. Slew rate control on the driver is used to minimize the radiated noise and cross talk. The driver’s outputs support 3-state operation to achieve bidirectional half duplex operation. The driver can tolerate a voltage on the signal pins of –1.0V to 5.5V with respect to local ground reference without damage. 9.7.2.2 Low Speed (1.5 Mbps) Driver Characteristics The rise and fall time of the signals on this cable are greater than 75ns and less than 300ns. The edges are matched to within ±20% to minimize RFI emissions and signal skew. USB data transmission is done with differential signals. A differential input receiver is used to accept the USB data signal. A differential 1 on the bus is represented by D+ being at least 200mV more positive than D– as seen at the receiver, and a differential 0 is represented by D– being at least 200mV more positive than D+ as seen at the receiver. The signal cross over point must be between 1.3V and 2.0V. ONE BIT TIME (1.5 Mb/s) VSE (max) VSE (min.) SIGNAL PINS PASS OUTPUT SPEC LEVELS WITH MINIMAL REFLECTIONS AND RINGING VSS Figure 9-11. Receiver Characteristics Technical Data 134 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Universal Serial Bus Module (USB) Freescale Semiconductor Universal Serial Bus Module (USB) Hardware Description The receiver features an input sensitivity of 200mV when both differential data inputs are in the differential common mode range of 0.8V to 2.5V as shown in Figure 9-12. In addition to the differential receiver, there is a single-ended receiver (schmitt trigger) for each of the two data lines. Differential Input voltage Range Differential Output Crossover Voltage Range –1.0 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0 3.2 5.5 INPUT VOLTAGE RANGE (VOLTS) Figure 9-12. Differential Input Sensitivity Range 9.7.2.3 Receiver Data Jitter The data receivers for all types of devices must be able to properly decode the differential data in the presence of jitter. The more of the bit time that any data edge can occupy and still be decoded, the more reliable the data transfer will be. Data receivers are required to decode differential data transitions that occur in a window plus and minus a nominal quarter bit time from the nominal (centered) data edge position. Jitter will be caused by the delay mismatches and by mismatches in the source and destination data rates (frequencies). The receive data jitter budget for low speed is given in Section 18. Electrical Specifications. The specification includes the consecutive (next) and paired transition values for each source of jitter. 9.7.2.4 Data Source Jitter The source of data can have some variation (jitter) in the timing of edges of the data transmitted. The time between any set of data transitions is N × TPeriod ± jitter time, where N is the number of bits between the transitions and TPeriod is defined as the actual period of the data rate. The data jitter is measured with the same capacitive load used for maximum rise and fall times and is measured at the crossover points of the data lines as shown in Figure 9-13. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Universal Serial Bus Module (USB) Technical Data 135 Universal Serial Bus Module (USB) tPeriod CROSSOVER POINTS DIFFERENTIAL DATA LINES JITTER CONSECUTIVE TRANSITIONS PAIRED TRANSITIONS Figure 9-13. Data Jitter For low-speed transmissions, the jitter time for any consecutive differential data transitions must be within ±25ns and within ±10ns for any set of paired differential data transitions. These jitter numbers include timing variations due to differential buffer delay, rise/fall time mismatches, internal clock source jitter, noise and other random effects. 9.7.2.5 Data Signal Rise and Fall Time The output rise time and fall time are measured between 10% and 90% of the signal. Edge transition time for the rising and falling edges of low-speed signals is 75ns (minimum) into a capacitive load (CL) of 200pF and 300ns (maximum) into a capacitive load of 600pF. The rising and falling edges should be transitioning (monotonic) smoothly when driving the cable to avoid excessive EMI. FALL TIME RISE TIME + 90% CL 90% DIFFERENTIAL DATA LINES 10% 10% + tR CL tF LOW SPEED: 75ns at CL = 200pF, 300ns at CL = 600 pF Figure 9-14. Data Signal Rise and Fall Time Technical Data 136 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Universal Serial Bus Module (USB) Freescale Semiconductor Universal Serial Bus Module (USB) I/O Registers 9.7.3 USB Control Logic The USB control logic manages data movement between the CPU and the transceiver. The control logic handles both transmit and receive operations on the USB. It contains the logic used to manipulate the transceiver and the endpoint registers. The byte count buffer is loaded with the active transmit endpoints byte count value during transmit operations. This same buffer is used for receive transactions to count the number of bytes received and, upon the end of the transaction, transfer that number to the receive endpoints byte count register. When transmitting, the control logic handles parallel-to-serial conversion, CRC generation, NRZI encoding, and bit stuffing. When receiving, the control logic handles sync detection, packet identification, end-of-packet detection, bit (un)stuffing, NRZI decoding, CRC validation, and serial-to-parallel conversion. Errors detected by the control logic include bad CRC, timeout while waiting for EOP, and bit stuffing violations. 9.8 I/O Registers These I/O registers control and monitor USB operation: • USB address register (UADDR) • USB control registers 0–4 (UCR0–UCR4) • USB status registers 0–1 (USR0–USR1) • USB interrupt registers 0–2 (UIR0–UIR2) • USB endpoint 0 data registers 0–7 (UE0D0–UE0D7) • USB endpoint 1 data registers 0–7 (UE1D0–UE1D7) • USB endpoint 2 data registers 0–7 (UE2D0–UE2D7) MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Universal Serial Bus Module (USB) Technical Data 137 Universal Serial Bus Module (USB) 9.8.1 USB Address Register Address: $0038 Bit 7 6 5 4 3 2 1 Bit 0 USBEN UADD6 UADD5 UADD4 UADD3 UADD2 UADD1 UADD0 0* 0 0 0 0 0 0 0 Read: Write: Reset: * USBEN bit is reset by POR or LVI reset only. Figure 9-15. USB Address Register (UADDR) USBEN — USB Module Enable This read/write bit enables and disables the USB module and the USB pins. When USBEN is set, the USB module is enabled and the PTE4 interrupt is disabled. When USBEN is clear, the USB module will not respond to any tokens, USB reset and USB related interrupts are disabled, and pins PTE4/D– and PTE3/D+ function as high current open-drain I/O port pins PTE4 and PTE3. 1 = USB function enabled and PTE4 interrupt is disabled 0 = USB function disabled including USB interrupt, reset and reset interrupt UADD[6:0] — USB Function Address These bits specify the USB address of the device. Reset clears these bits. Technical Data 138 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Universal Serial Bus Module (USB) Freescale Semiconductor Universal Serial Bus Module (USB) I/O Registers 9.8.2 USB Interrupt Register 0 Address: $0039 Bit 7 6 5 4 3 EOPIE SUSPND TXD2IE RXD2IE TXD1IE 0 0 0 0 0 Read: 2 1 Bit 0 TXD0IE RXD0IE 0 0 0 Write: Reset: 0 = Unimplemented Figure 9-16. USB Interrupt Register 0 (UIR0) EOPIE — End-of-Packet Detect Interrupt Enable This read/write bit enables the USB to generate CPU interrupt requests when the EOPF bit becomes set. Reset clears the EOPIE bit. 1 = End-of-packet sequence detection can generate a CPU interrupt request 0 = End-of-packet sequence detection cannot generate a CPU interrupt request SUSPND — USB Suspend Bit To save power, this read/write bit should be set by the software if a 3ms constant idle state is detected on the USB bus. Setting this bit puts the transceiver into a power-saving mode. The RESUMF flag must be cleared before setting SUSPND. Software must clear this bit after the resume flag (RESUMF) is set while this resume interrupt flag is serviced. TXD2IE — Endpoint 2 Transmit Interrupt Enable This read/write bit enables the transmit endpoint 2 to generate CPU interrupt requests when the TXD2F bit becomes set. Reset clears the TXD2IE bit. 1 = Transmit endpoint 2 can generate a CPU interrupt request 0 = Transmit endpoint 2 cannot generate a CPU interrupt request MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Universal Serial Bus Module (USB) Technical Data 139 Universal Serial Bus Module (USB) RXD2IE — Endpoint 2 Receive Interrupt Enable This read/write bit enables the receive endpoint 2 to generate CPU interrupt requests when the RXD2F bit becomes set. Reset clears the RXD2IE bit. 1 = Receive endpoint 2 can generate a CPU interrupt request 0 = Receive endpoint 2 cannot generate a CPU interrupt request TXD1IE — Endpoint 1 Transmit Interrupt Enable This read/write bit enables the transmit endpoint 1 to generate CPU interrupt requests when the TXD1F bit becomes set. Reset clears the TXD1IE bit. 1 = Transmit endpoints 1 can generate a CPU interrupt request 0 = Transmit endpoints 1 cannot generate a CPU interrupt request TXD0IE — Endpoint 0 Transmit Interrupt Enable This read/write bit enables the transmit endpoint 0 to generate CPU interrupt requests when the TXD0F bit becomes set. Reset clears the TXD0IE bit. 1 = Transmit endpoint 0 can generate a CPU interrupt request 0 = Transmit endpoint 0 cannot generate a CPU interrupt request RXD0IE — Endpoint 0 Receive Interrupt Enable This read/write bit enables the receive endpoint 0 to generate CPU interrupt requests when the RXD0F bit becomes set. Reset clears the RXD0IE bit. 1 = Receive endpoint 0 can generate a CPU interrupt request 0 = Receive endpoint 0 cannot generate a CPU interrupt request Technical Data 140 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Universal Serial Bus Module (USB) Freescale Semiconductor Universal Serial Bus Module (USB) I/O Registers 9.8.3 USB Interrupt Register 1 Address: Read: $003A Bit 7 6 5 4 3 2 1 Bit 0 EOPF RSTF TXD2F RXD2F TXD1F RESUMF TXD0F RXD0F 0 0 0 0 0 0 0 0 Write: Reset: = Unimplemented Figure 9-17. USB Interrupt Register 1 (UIR1) EOPF — End-of-Packet Detect Flag This read-only bit is set when a valid end-of-packet sequence is detected on the D+ and D– lines. Software must clear this flag by writing a logic 1 to the EOPFR bit. Reset clears this bit. Writing to EOPF has no effect. 1 = End-of-packet sequence has been detected 0 = End-of-packet sequence has not been detected RSTF — USB Reset Flag This read-only bit is set when a valid reset signal state is detected on the D+ and D– lines. If the URSTD bit of the configuration register (CONFIG) is clear, this reset detection will generate an internal reset signal to reset the CPU and other peripherals including the USB module. If the URSTD bit is set, this reset detection will generate an USB interrupt. This bit is cleared by writing a logic 1 to the RSTFR bit. This bit also is cleared by a POR reset. NOTE: The USB bit in the RSR register (see 8.8.2 Reset Status Register) is also a USB reset indicator. TXD2F — Endpoint 2 Data Transmit Flag This read-only bit is set after the data stored in endpoint 2 transmit buffers has been sent and an ACK handshake packet from the host is received. Once the next set of data is ready in the transmit buffers, software must clear this flag by writing a logic 1 to the TXD2FR bit. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Universal Serial Bus Module (USB) Technical Data 141 Universal Serial Bus Module (USB) To enable the next data packet transmission, TX2E also must be set. If the TXD2F bit is not cleared, a NAK handshake will be returned in the next IN transaction. Reset clears this bit. Writing to TXD2F has no effect. 1 = Transmit on endpoint 2 has occurred 0 = Transmit on endpoint 2 has not occurred RXD2F — Endpoint 2 Data Receive Flag This read-only bit is set after the USB module has received a data packet and responded with an ACK handshake packet. Software must clear this flag by writing a logic 1 to the RXD2FR bit after all of the received data has been read. Software also must set the RX2E bit to 1 to enable the next data packet reception. If the RXD2F bit is not cleared, a NAK handshake will be returned in the next OUT transaction. Reset clears this bit. Writing to RXD2F has no effect. 1 = Receive on endpoint 2 has occurred 0 = Receive on endpoint 2 has not occurred TXD1F — Endpoint 1 Data Transmit Flag This read-only bit is set after the data stored in the endpoint 1 transmit buffer has been sent and an ACK handshake packet from the host is received. Once the next set of data is ready in the transmit buffers, software must clear this flag by writing a logic 1 to the TXD1FR bit. To enable the next data packet transmission, TX1E also must be set. If the TXD1F bit is not cleared, a NAK handshake will be returned in the next IN transaction. Reset clears this bit. Writing to TXD1F has no effect. 1 = Transmit on endpoint 1has occurred 0 = Transmit on endpoint 1has not occurred RESUMF — Resume Flag This read-only bit is set when USB bus activity is detected while the SUSPND bit is set. Software must clear this flag by writing a logic 1 to the RESUMFR bit. Reset clears this bit. Writing a logic 0 to RESUMF has no effect. 1 = USB bus activity has been detected 0 = No USB bus activity has been detected Technical Data 142 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Universal Serial Bus Module (USB) Freescale Semiconductor Universal Serial Bus Module (USB) I/O Registers TXD0F — Endpoint 0 Data Transmit Flag This read-only bit is set after the data stored in endpoint 0 transmit buffers has been sent and an ACK handshake packet from the host is received. Once the next set of data is ready in the transmit buffers, software must clear this flag by writing a logic 1 to the TXD0FR bit. To enable the next data packet transmission, TX0E also must be set. If the TXD0F bit is not cleared, a NAK handshake will be returned in the next IN transaction. Reset clears this bit. Writing to TXD0F has no effect. 1 = Transmit on endpoint 0 has occurred 0 = Transmit on endpoint 0 has not occurred RXD0F — Endpoint 0 Data Receive Flag This read-only bit is set after the USB module has received a data packet and responded with an ACK handshake packet. Software must clear this flag by writing a logic 1 to the RXD0FR bit after all of the received data has been read. Software also must set the RX0E bit to 1 to enable the next data packet reception. If the RXD0F bit is not cleared, the USB will respond with a NAK handshake to any endpoint 0 OUT tokens; but does not respond to a SETUP token. Reset clears this bit. Writing to RXD0F has no effect. 1 = Receive on endpoint 0 has occurred 0 = Receive on endpoint 0 has not occurred MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Universal Serial Bus Module (USB) Technical Data 143 Universal Serial Bus Module (USB) 9.8.4 USB Interrupt Register 2 Address: $0018 Bit 7 6 5 4 3 2 1 Bit 0 Read: 0 0 0 0 0 0 0 0 Write: EOPFR RSTFR TXD2FR RXD2FR Reset: 0 0 0 0 TXD1FR RESUMFR TXD0FR 0 0 0 RXD0FR 0 Figure 9-18. USB Interrupt Register 2 (UIR2) EOPFR — End-of-Packet Flag Reset Writing a logic 1 to this write-only bit will clear the EOPF bit if it is set. Writing a logic 0 to the EOPFR has no effect. Reset clears this bit. RSTFR — Clear Reset Indicator Bit Writing a logic 1 to this write-only bit will clear the RSTF bit if it is set. Writing a logic 0 to the RSTFR has no effect. Reset clears this bit. TXD2FR — Endpoint 2 Transmit Flag Reset Writing a logic 1 to this write-only bit will clear the TXD2F bit if it is set. Writing a logic 0 to TXD2FR has no effect. Reset clears this bit. RXD2FR — Endpoint 2 Receive Flag Reset Writing a logic 1 to this write-only bit will clear the RXD2F bit if it is set. Writing a logic 0 to RXD2FR has no effect. Reset clears this bit. TXD1FR — Endpoint 1 Transmit Flag Reset Writing a logic 1 to this write-only bit will clear the TXD1F bit if it is set. Writing a logic 0 to TXD1FR has no effect. Reset clears this bit. RESUMFR — Resume Flag Reset Writing a logic 1 to this write-only bit will clear the RESUMF bit if it is set. Writing to RESUMFR has no effect. Reset clears this bit. TXD0FR — Endpoint 0 Transmit Flag Reset Writing a logic 1 to this write-only bit will clear the TXD0F bit if it is set. Writing a logic 0 to TXD0FR has no effect. Reset clears this bit. RXD0FR — Endpoint 0 Receive Flag Reset Writing a logic 1 to this write-only bit will clear the RXD0F bit if it is set. Writing a logic 0 to RXD0FR has no effect. Reset clears this bit. Technical Data 144 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Universal Serial Bus Module (USB) Freescale Semiconductor Universal Serial Bus Module (USB) I/O Registers 9.8.5 USB Control Register 0 Address: $003B Bit 7 Read: 6 5 4 3 2 1 Bit 0 TX0E RX0E TP0SIZ3 TP0SIZ2 TP0SIZ1 TP0SIZ0 0 0 0 0 0 0 0 T0SEQ Write: Reset: 0 0 Figure 9-19. USB Control Register 0 (UCR0) T0SEQ — Endpoint 0 Transmit Sequence Bit This read/write bit determines which type of data packet (DATA0 or DATA1) will be sent during the next IN transaction directed at endpoint 0. Toggling of this bit must be controlled by software. Reset clears this bit. 1 = DATA1 token active for next endpoint 0 transmit 0 = DATA0 token active for next endpoint 0 transmit TX0E — Endpoint 0 Transmit Enable This read/write bit enables a transmit to occur when the USB host controller sends an IN token to endpoint 0. Software should set this bit when data is ready to be transmitted. It must be cleared by software when no more endpoint 0 data needs to be transmitted. If this bit is 0 or the TXD0F is set, the USB will respond with a NAK handshake to any endpoint 0 IN tokens. Reset clears this bit. 1 = Data is ready to be sent 0 = Data is not ready. Respond with NAK RX0E — Endpoint 0 Receive Enable This read/write bit enables a receive to occur when the USB host controller sends an OUT token to endpoint 0. Software should set this bit when data is ready to be received. It must be cleared by software when data cannot be received. If this bit is 0 or the RXD0F is set, the USB will respond with a NAK handshake to any endpoint 0 OUT tokens; but does not respond to a SETUP token. Reset clears this bit. 1 = Data is ready to be received 0 = Not ready for data. Respond with NAK MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Universal Serial Bus Module (USB) Technical Data 145 Universal Serial Bus Module (USB) TP0SIZ3–TP0SIZ0 — Endpoint 0 Transmit Data Packet Size These read/write bits store the number of transmit data bytes for the next IN token request for endpoint 0. These bits are cleared by reset. 9.8.6 USB Control Register 1 Address: $003C Bit 7 6 5 T1SEQ STALL1 TX1E 0 0 0 4 3 2 1 Bit 0 TP1SIZ2 TP1SIZ1 TP1SIZ0 0 0 0 Read: FRESUM TP1SIZ3 Write: Reset: 0 0 Figure 9-20. USB Control Register 1 (UCR1) T1SEQ — Endpoint 1 Transmit Sequence Bit This read/write bit determines which type of data packet (DATA0 or DATA1) will be sent during the next IN transaction directed to endpoint 1. Toggling of this bit must be controlled by software. Reset clears this bit. 1 = DATA1 token active for next endpoint 1 transmit 0 = DATA0 token active for next endpoint 1 transmit STALL1 — Endpoint 1 Force Stall Bit This read/write bit causes endpoint 1 to return a STALL handshake when polled by either an IN or OUT token by the USB host controller. Reset clears this bit. 1 = Send STALL handshake 0 = Default TX1E — Endpoint 1 Transmit Enable This read/write bit enables a transmit to occur when the USB host controller sends an IN token to endpoint 1. The appropriate endpoint enable bit, ENABLE1 bit in the UCR3 register, also should be set. Software should set the TX1E bit when data is ready to be transmitted. It must be cleared by software when no more data needs to be transmitted. Technical Data 146 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Universal Serial Bus Module (USB) Freescale Semiconductor Universal Serial Bus Module (USB) I/O Registers If this bit is 0 or the TXD1F is set, the USB will respond with a NAK handshake to any endpoint 1 directed IN tokens. Reset clears this bit. 1 = Data is ready to be sent 0 = Data is not ready. Respond with NAK FRESUM — Force Resume This read/write bit forces a resume state (K or non-idle state) onto the USB data lines to initiate a remote wakeup. Software should control the timing of the forced resume to be between 10 and 15 ms. Setting this bit will not cause the RESUMF bit to be set. 1 = Force data lines to K state 0 = Default TP1SIZ3–TP1SIZ0 — Endpoint 1 Transmit Data Packet Size These read/write bits store the number of transmit data bytes for the next IN token request for endpoint 1. These bits are cleared by reset. 9.8.7 USB Control Register 2 Address: $0019 Bit 7 6 5 4 3 2 1 Bit 0 T2SEQ STALL2 TX2E RX2E TP2SIZ3 TP2SIZ2 TP2SIZ1 TP2SIZ0 0 0 0 0 0 0 0 0 Read: Write: Reset: Figure 9-21. USB Control Register 2 (UCR2) T2SEQ — Endpoint 2 Transmit Sequence Bit This read/write bit determines which type of data packet (DATA0 or DATA1) will be sent during the next IN transaction directed to endpoint 2. Toggling of this bit must be controlled by software. Reset clears this bit. 1 = DATA1 token active for next endpoint 2 transmit 0 = DATA0 token active for next endpoint 2 transmit MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Universal Serial Bus Module (USB) Technical Data 147 Universal Serial Bus Module (USB) STALL2 — Endpoint 2 Force Stall Bit This read/write bit causes endpoint 2 to return a STALL handshake when polled by either an IN or OUT token by the USB host controller. Reset clears this bit. 1 = Send STALL handshake 0 = Default TX2E — Endpoint 2 Transmit Enable This read/write bit enables a transmit to occur when the USB host controller sends an IN token to endpoint 2. The appropriate endpoint enable bit, ENABLE2 bit in the UCR3 register, also should be set. Software should set the TX2E bit when data is ready to be transmitted. It must be cleared by software when no more data needs to be transmitted. If this bit is 0 or the TXD2F is set, the USB will respond with a NAK handshake to any endpoint 2 directed IN tokens. Reset clears this bit. 1 = Data is ready to be sent 0 = Data is not ready. Respond with NAK RX2E — Endpoint 2 Receive Enable This read/write bit enables a receive to occur when the USB host controller sends an OUT token to endpoint 2. Software should set this bit when data is ready to be received. It must be cleared by software when data cannot be received. If this bit is 0 or the RXD2F is set, the USB will respond with a NAK handshake to any endpoint 2 OUT tokens. Reset clears this bit. 1 = Data is ready to be received 0 = Not ready for data. Respond with NAK TP2SIZ3–TP2SIZ0 — Endpoint 2 Transmit Data Packet Size These read/write bits store the number of transmit data bytes for the next IN token request for endpoint 2. These bits are cleared by reset. Technical Data 148 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Universal Serial Bus Module (USB) Freescale Semiconductor Universal Serial Bus Module (USB) I/O Registers 9.8.8 USB Control Register 3 Address: Read: $001A Bit 7 6 TX1ST 0 Write: Reset: 5 4 OSTALL0 ISTALL0 0 0 3 2 1 Bit 0 0 PULLEN ENABLE2 ENABLE1 TX1STR 0 0 0 0* 0 0 = Unimplemented * PULLEN bit is reset by POR or LVI reset only. Figure 9-22. USB Control Register 3 (UCR3) TX1ST — Endpoint 0 Transmit First Flag This read-only bit is set if the endpoint 0 data transmit flag (TXD0F) is set when the USB control logic is setting the endpoint 0 data receive flag (RXD0F). In other words, if an unserviced endpoint 0 transmit flag is still set at the end of an endpoint 0 reception, then this bit will be set. This bit lets the firmware know that the endpoint 0 transmission happened before the endpoint 0 reception. Reset clears this bit. 1 = IN transaction occurred before SETUP/OUT 0 = IN transaction occurred after SETUP/OUT TX1STR — Clear Endpoint 0 Transmit First Flag Writing a logic 1 to this write-only bit will clear the TX1ST bit if it is set. Writing a logic 0 to the TX1STR has no effect. Reset clears this bit. OSTALL0 — Endpoint 0 Force STALL Bit for OUT token This read/write bit causes endpoint 0 to return a STALL handshake when polled by an OUT token by the USB host controller. Reset clears this bit. 1 = Send STALL handshake 0 = Default MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Universal Serial Bus Module (USB) Technical Data 149 Universal Serial Bus Module (USB) ISTALL0 — Endpoint 0 Force STALL Bit for IN token This read/write bit causes endpoint 0 to return a STALL handshake when polled by an IN token by the USB host controller. Reset clears this bit. 1 = Send STALL handshake 0 = Default PULLEN — Pull-up Enable This read/write bit controls the pull-up option for the USB D– pin if the USB module is enabled. 1 = Configure D– pin to have internal pull-up 0 = Disconnect D– pin internal pull-up ENABLE2 — Endpoint 2 Enable This read/write bit enables endpoint 2 and allows the USB to respond to IN or OUT packets addressed to endpoint 2. Reset clears this bit. 1 = Endpoint 2 is enabled and can respond to an IN or OUT token 0 = Endpoint 2 is disabled ENABLE1 — Endpoint 1 Enable This read/write bit enables endpoint 1 and allows the USB to respond to IN packets addressed to endpoint 1. Reset clears this bit. 1 = Endpoint 1 is enabled and can respond to an IN token 0 = Endpoint 1 is disabled Technical Data 150 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Universal Serial Bus Module (USB) Freescale Semiconductor Universal Serial Bus Module (USB) I/O Registers 9.8.9 USB Control Register 4 USB control register 4 directly controls the USB data pins D+ and D–. If the FUSBO bit, and the USBEN bit of the USB address register (UADDR) are set, the output buffers of the USB modules are enabled and the corresponding levels of the USB data pins D+ and D– are equal to the values set by the FDP and the FDM bits. Address: Read: $001B Bit 7 6 5 4 3 0 0 0 0 0 2 1 Bit 0 FUSBO FDP FDM 0 0 0 Write: Reset: 0 0 0 0 0 = Unimplemented Figure 9-23. USB Control Register 4 (UCR4) FUSBO — Force USB Output This read/write bit enables the USB output buffers. 1 = Enables USB output buffers 0 = USB module in normal operation FDP — Force D+ This read/write bit determinates the output level of D+. 1 = D+ at output high level 0 = D+ at output low level FDM — Force D– This read/write bit determinates the output level of D–. 1 = D– at output high level 0 = D– at output low level NOTE: Customers must be very careful when setting the UCR4 register. When the FUSBO and the USBEN bits are set, the USB module is in output mode and it will not recognize any USB signals including the USB reset signal. The UCR4 register is used for some special applications. Customers are not normally expected to use this register. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Universal Serial Bus Module (USB) Technical Data 151 Universal Serial Bus Module (USB) 9.8.10 USB Status Register 0 Address: Read: $003D Bit 7 6 5 4 3 2 1 Bit 0 R0SEQ SETUP 0 0 RP0SIZ3 RP0SIZ2 RP0SIZ1 RP0SIZ0 Write: Reset: Unaffected by reset = Unimplemented Figure 9-24. USB Status Register 0 (USR0) R0SEQ — Endpoint 0 Receive Sequence Bit This read-only bit indicates the type of data packet last received for endpoint 0 (DATA0 or DATA1). 1 = DATA1 token received in last endpoint 0 receive 0 = DATA0 token received in last endpoint 0 receive SETUP — SETUP Token Detect Bit This read-only bit indicates that a valid SETUP token has been received. 1 = Last token received for endpoint 0 was a SETUP token 0 = Last token received for endpoint 0 was not a SETUP token RP0SIZ3–RP0SIZ0 — Endpoint 0 Receive Data Packet Size These read-only bits store the number of data bytes received for the last OUT or SETUP transaction for endpoint 0. Technical Data 152 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Universal Serial Bus Module (USB) Freescale Semiconductor Universal Serial Bus Module (USB) I/O Registers 9.8.11 USB Status Register 1 Address: Read: $003E Bit 7 6 5 4 3 2 1 Bit 0 R2SEQ TXACK TXNAK TXSTL RP2SIZ3 RP2SIZ2 RP2SIZ1 RP2SIZ0 U 0 0 0 U U U U Write: Reset: = Unimplemented U = Unaffected by reset Figure 9-25. USB Status Register 1 (USR1) R2SEQ — Endpoint 2 Receive Sequence Bit This read-only bit indicates the type of data packet last received for endpoint 2 (DATA0 or DATA1). 1 = DATA1 token received in last endpoint 2 receive 0 = DATA0 token received in last endpoint 2 receive TXACK — ACK Token Transmit Bit This read-only bit indicates that an ACK token has been transmitted. This bit is updated at the end of the EP0 data transmission. 1 = Last token transmitted for endpoint 0 was an ACK token 0 = Last token transmitted for endpoint 0 was not an ACK token TXNAK — NAK Token Transmit Bit This read-only bit indicates that a TXNAK token has been transmitted. This bit is updated at the end of the EP0 data transmission. 1 = Last token transmitted for endpoint 0 was a NAK token 0 = Last token transmitted for endpoint 0 was not a NAK token TXSTL — STALL Token Transmit Bit This read-only bit indicates that a STALL token has been transmitted. This bit is updated at the end of the EP0 data transmission. 1 = Last token transmitted for endpoint 0 was a STALL token 0 = Last token transmitted for endpoint 0 was not a STALL token RP2SIZ3–RP2SIZ0 — Endpoint 2 Receive Data Packet Size These read-only bits store the number of data bytes received for the last OUT transaction for endpoint 2. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Universal Serial Bus Module (USB) Technical Data 153 Universal Serial Bus Module (USB) 9.8.12 USB Endpoint 0 Data Registers Address: $0020 UE0D0 Bit 7 6 5 4 3 2 1 Bit 0 Read: UE0R07 UE0R06 UE0R05 UE0R04 UE0R03 UE0R02 UE0R01 UE0R00 Write: UE0T07 UE0T06 UE0T05 UE0T04 UE0T03 UE0T02 UE0T01 UE0T00 Reset: Unaffected by reset ↓ Address: $0027 ↓ UE0D7 Read: UE0R77 UE0R76 UE0R75 UE0R74 UE0R73 UE0R72 UE0R71 UE0R70 Write: UE0T77 UE0T76 UE0T75 UE0T74 UE0T73 UE0T72 UE0T71 UE0T70 Reset: Unaffected by reset Figure 9-26. USB Endpoint 0 Data Registers (UE0D0–UE0D7) UE0Rx7–UE0Rx0 — Endpoint 0 Receive Data Buffer These read-only bits are serially loaded with OUT token or SETUP token data directed at endpoint 0. The data is received over the USB’s D+ and D– pins. UE0Tx7–UE0Tx0 — Endpoint 0 Transmit Data Buffer These write-only buffers are loaded by software with data to be sent on the USB bus on the next IN token directed at endpoint 0. Technical Data 154 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Universal Serial Bus Module (USB) Freescale Semiconductor Universal Serial Bus Module (USB) I/O Registers 9.8.13 USB Endpoint 1 Data Registers Address: $0028 UE1D0 Bit 7 6 5 4 3 2 1 Bit 0 UE1T06 UE1T05 UE1T04 UE1T03 UE1T02 UE1T01 UE1T00 Read: Write: UE1T07 Reset: Unaffected by reset ↓ Address: $002F ↓ UE1D7 Read: Write: UE1T77 UE1T76 UE1T75 Reset: UE1T74 UE1T73 UE1T72 UE1T71 UE1T70 Unaffected by reset = Unimplemented Figure 9-27. USB Endpoint 1 Data Registers (UE1D0–UE1D7) UE1Tx7–UE1Tx0 — Endpoint 1 Transmit or Receive Data Buffer These write-only buffers are loaded by software with data to be sent on the USB bus on the next IN token directed at endpoint 1. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Universal Serial Bus Module (USB) Technical Data 155 Universal Serial Bus Module (USB) 9.8.14 USB Endpoint 2 Data Registers Address: $0030 UE2D0 Bit 7 6 5 4 3 2 1 Bit 0 Read: UE2R07 UE2R06 UE2R05 UE2R04 UE2R03 UE2R02 UE2R01 UE2R00 Write: UE2T07 UE2T06 UE2T05 UE2T04 UE2T03 UE2T02 UE2T01 UE2T00 Reset: Unaffected by reset ↓ Address: $0037 ↓ UE2D7 Read: UE2R77 UE2R76 UE2R75 UE2R74 UE2R73 UE2R72 UE2R71 UE2R70 Write: UE2T77 UE2T76 UE2T75 UE2T74 UE2T73 UE2T72 UE2T71 UE2T70 Reset: Unaffected by reset Figure 9-28. USB Endpoint 2 Data Registers (UE2D0–UE2D7) UE2Rx7–UE2Rx0 — Endpoint 2 Receive Data Buffer These read-only bits are serially loaded with OUT token data directed at endpoint 2. The data is received over the USB’s D+ and D– pins. UE2Tx7–UE2Tx0 — Endpoint 2 Transmit Data Buffer These write-only buffers are loaded by software with data to be sent on the USB bus on the next IN token directed at endpoint 2. Technical Data 156 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Universal Serial Bus Module (USB) Freescale Semiconductor Universal Serial Bus Module (USB) USB Interrupts 9.9 USB Interrupts The USB module is capable of generating interrupts and causing the CPU to execute the USB interrupt service routine. There are three types of USB interrupts: • End-of-transaction interrupts signify either a completed transaction receive or transmit transaction. • Resume interrupts signify that the USB bus is reactivated after having been suspended. • End-of-packet interrupts signify that a low-speed end-of-packet signal was detected. All USB interrupts share the same interrupt vector. Firmware is responsible for determining which interrupt is active. 9.9.1 USB End-of-Transaction Interrupt There are five possible end-of-transaction interrupts: • Endpoint 0 or 2 receive • Endpoint 0, 1 or 2 transmit End-of-transaction interrupts occur as detailed in the following sections. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Universal Serial Bus Module (USB) Technical Data 157 Universal Serial Bus Module (USB) 9.9.1.1 Receive Control Endpoint 0 For a control OUT transaction directed at endpoint 0, the USB module will generate an interrupt by setting the RXD0F flag in the UIR0 register. The conditions necessary for the interrupt to occur are shown in the flowchart in Figure 9-29. VALID OUT TOKEN RECEIVED FOR ENDPOINT 0 Y VALID DATA TOKEN RECEIVED FOR ENDPOINT 0? N TIMEOUT NO RESPONSE FROM USB FUNCTION Y USB MODULE ENABLED? (USBEN = 1) N NO RESPONSE FROM USB FUNCTION N SEND STALL HANDSHAKE N SEND NAK HANDSHAKE Y ENDPOINT 0 RECEIVE NOT STALLED? (OSTALL0 = 0) Y ENDPOINT 0 RECEIVE READY TO RECEIVE? (RX0E = 1) AND (RXD0F = 0) Y ACCEPT DATA SET/CLEAR R0SEQ BIT ERROR FREE DATA PACKET? N IGNORE TRANSACTION NO RESPONSE FROM USB FUNCTION Y SET RXD0F TO 1 RECEIVE CONTROL ENDPOINT INTERRUPT ENABLED? (RXD0IE = 1) N Y VALID TRANSACTION INTERRUPT GENERATED NO INTERRUPT Figure 9-29. OUT Token Data Flow for Receive Endpoint 0 Technical Data 158 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Universal Serial Bus Module (USB) Freescale Semiconductor Universal Serial Bus Module (USB) USB Interrupts SETUP transactions cannot be stalled by the USB function. A SETUP received by a control endpoint will clear the ISTALL0 and OSTALL0 bits. The conditions for receiving a SETUP interrupt are shown in Figure 9-30. VALID SETUP TOKEN RECEIVED FOR ENDPOINT 0? Y USB MODULE ENABLED? (USBEN = 1) N NO RESPONSE FROM USB FUNCTION N NO RESPONSE FROM USB FUNCTION Y ENDPOINT 0 RECEIVE READY TO RECEIVE? (RX0E = 1) AND (RXD0F = 0) Y ACCEPT DATA SET/CLEAR R0SEQ BIT SET SETUP BIT TO 1 ERROR FREE DATA PACKET? N IGNORE TRANSACTION NO RESPONSE FROM USB FUNCTION Y SET RXD0F TO 1 RECEIVE CONTROL ENDPOINT INTERRUPT ENABLED? (RXD0IE = 1) N Y VALID TRANSACTION INTERRUPT GENERATED NO INTERRUPT Figure 9-30. SETUP Token Data Flow for Receive Endpoint 0 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Universal Serial Bus Module (USB) Technical Data 159 Universal Serial Bus Module (USB) 9.9.1.2 Transmit Control Endpoint 0 For a control IN transaction directed at endpoint 0, the USB module will generate an interrupt by setting the TXD0F flag in the UIR1 register. The conditions necessary for the interrupt to occur are shown in the flowchart in Figure 9-31. VALID IN TOKEN RECEIVED FOR ENDPOINT 0 Y USB MODULE ENABLED? (USBEN = 1) N NO RESPONSE FROM USB FUNCTION N SEND STALL HANDSHAKE N SEND NAK HANDSHAKE N NO RESPONSE FROM USB FUNCTION Y TRANSMIT ENDPOINT NOT STALLED BY FIRMWARE (ISTALL0 = 0)? Y TRANSMIT ENDPOINT READY TO TRANSFER? (TX0E = 1) AND (TXD0F = 0) Y SEND DATA DATA PID SET BY T0SEQ ACK RECEIVED AND NO TIMEOUT CONDITION OCCURS? Y SET TXD0F TO 1 TRANSMIT ENDPOINT INTERRUPT ENABLED? (TXD0IE = 1) N Y VALID TRANSACTION INTERRUPT GENERATED NO INTERRUPT Figure 9-31. IN Token Data Flow for Transmit Endpoint 0 Technical Data 160 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Universal Serial Bus Module (USB) Freescale Semiconductor Universal Serial Bus Module (USB) USB Interrupts 9.9.1.3 Transmit Endpoint 1 For an IN transaction directed at endpoint 1, the USB module will generate an interrupt by setting the TXD1F in the UIR1 register. The conditions necessary for the interrupt to occur are shown in Figure 9-32. VALID IN TOKEN RECEIVED FOR ENDPOINT 1 Y USB MODULE ENABLED? (USBEN = 1) N NO RESPONSE FROM USB FUNCTION N SEND STALL HANDSHAKE N SEND NAK HANDSHAKE N NO RESPONSE FROM USB FUNCTION N NO RESPONSE FROM USB FUNCTION Y TRANSMIT ENDPOINT NOT STALLED BY FIRMWARE (STALL1 = 1)? Y TRANSMIT ENDPOINT READY TO TRANSFER? (TX1E = 1) AND (TXD1F = 0) AND (UE1TR = 0) Y TRANSMIT ENDPOINT ENABLED? (ENABLE = 1) Y SEND DATA DATA PID SET BY T1SEQ ACK RECEIVED AND NO TIMEOUT CONDITION OCCURS? Y SET TXD1F TO 1 TRANSMIT ENDPOINT INTERRUPT ENABLED? (TXD1IE = 1) N Y VALID TRANSACTION INTERRUPT GENERATED NO INTERRUPT Figure 9-32. IN Token Data Flow for Transmit Endpoint 1 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Universal Serial Bus Module (USB) Technical Data 161 Universal Serial Bus Module (USB) 9.9.1.4 Transmit Endpoint 2 For an IN transaction directed at endpoint 2, the USB module will generate an interrupt by setting the TXD2F in the UIR1 register. 9.9.1.5 Receive Endpoint 2 For an OUT transaction directed at endpoint 2, the USB module will generate an interrupt by setting the RXD2F in the UIR1 register. 9.9.2 Resume Interrupt The USB module will generate a CPU interrupt if low-speed bus activity is detected after entering the suspend state. A transition of the USB data lines to the non-idle state (K state) while in the suspend mode will set the RESUMF flag in the UIR1 register. There is no interrupt enable bit for this interrupt source and an interrupt will be executed if the I-bit in the CCR is cleared. A resume interrupt can only occur while the MCU is in the suspend mode. 9.9.3 End-of-Packet Interrupt The USB module can generate a USB interrupt upon detection of an end-of-packet signal for low-speed devices. Upon detection of an end-of-packet signal, the USB module sets the EOPF bit and will generate a CPU interrupt if the EOPIE bit in the UIR0 register is set. Technical Data 162 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Universal Serial Bus Module (USB) Freescale Semiconductor Technical Data — MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 Section 10. Monitor ROM (MON) 10.1 Contents 10.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163 10.3 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164 10.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .164 10.4.1 Entering Monitor Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166 10.4.2 Baud Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .169 10.4.3 Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170 10.4.4 Echoing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170 10.4.5 Break Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171 10.4.6 Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171 10.5 Security. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175 10.2 Introduction This section describes the monitor ROM (MON) and the monitor mode entry methods. The monitor ROM allows complete testing of the MCU through a single-wire interface with host computer. This mode is also used for programming and erasing of FLASH memory in the MCU. Monitor mode entry can be achieved without use of the higher voltage, VDD + VHI, as long as vector addresses $FFFE and $FFFF are blank, thus reducing the hardware requirements for in-circuit programming. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Monitor ROM (MON) Technical Data 163 Monitor ROM (MON) 10.3 Features Features of the monitor ROM include the following: • Normal user-mode pin functionality • One pin dedicated to serial communication between monitor ROM and host computer • Standard mark/space non-return-to-zero (NRZ) communication with host computer • Execution of code in RAM or FLASH • FLASH memory security feature1 • FLASH memory programming interface • 976 bytes monitor ROM code size • Monitor mode entry without high voltage, VDD + VHI, if reset vector is blank ($FFFE and $FFFF contain $FF) • Standard monitor mode entry if high voltage, VDD + VHI, is applied to IRQ 10.4 Functional Description The monitor ROM receives and executes commands from a host computer. Figure 10-1 shows a example circuit used to enter monitor mode and communicate with a host computer via a standard RS-232 interface. Simple monitor commands can access any memory address. In monitor mode, the MCU can execute host-computer code in RAM while most MCU pins retain normal operating mode functions. All communication between the host computer and the MCU is through the PTA0 pin. A level-shifting and multiplexing interface is required between PTA0 and the host computer. PTA0 is used in a wired-OR configuration and requires a pull-up resistor. 1. No security feature is absolutely secure. However, Freescale’s strategy is to make reading or copying the FLASH difficult for unauthorized users. Technical Data 164 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Monitor ROM (MON) Freescale Semiconductor Monitor ROM (MON) Functional Description VDD 10k Ω VDD + VHI RST 0.1 µF 10k Ω HC908JB8 SW2 C (SEE NOTE 2) IRQ D VREG + 4.7 µF 0.1 µF VDD VDD 6MHz VDD 0.1 µF VSS (SEE NOTE 3) 10 µF 10 µF MC145407 + + E 20 + 3 18 4 17 2 19 SW3 fXCLK 6MHz 10 µF 20 pF OSC1 F E 10MΩ 1 OSC2 F + 10 µF VDD 3.3V 20 pF 10 kΩ DB-25 2 3 A 5 6 16 (SEE NOTE 1) SW1 PTA3 B 15 3.3V 7 1 MC74LCX125 3.3V 14 2 3 6 5 10 kΩ 4 PTA0 3.3V 10 kΩ 7 PTA1 PTA2 NOTES: 1. Affects high voltage entry to monitor mode only (SW2 at position C): SW1: Position A — Bus clock = fXCLK ÷ 2 SW1: Position B — Bus clock = fXCLK 2. SW2: Position C — High-voltage entry to monitor mode. SW2: Position D — Low-voltage entry to monitor mode (with blank reset vector). See Section 18 for IRQ voltage level requirements. 3. SW3: Position E — OSC1 directly driven by external oscillator. SW3: Position F — OSC1 driven by crystal oscillator circuit. 10 kΩ Figure 10-1. Monitor Mode Circuit MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Monitor ROM (MON) Technical Data 165 Monitor ROM (MON) 10.4.1 Entering Monitor Mode Table 10-1 shows the pin conditions for entering monitor mode. As specified in the table, monitor mode may be entered after a POR and will allow communication at 9600 baud provided one of the following sets of conditions is met: 1. If IRQ = VDD + VHI: – External clock on OSC1 is 3MHz – PTA3 = low 2. If IRQ = VDD + VHI: – External clock on OSC1 is 6MHz – PTA3 = high 3. If $FFFE & $FFFF is blank (contains $FF): – External clock on OSC1 is 6MHz – IRQ = VDD Table 10-1. Mode Entry Requirements and Options IRQ $FFFE and $FFFF PTA3 PTA2 PTA1 PTA0 Bus Frequency, fBUS External Clock, fXCLK VDD + VHI X 0 0 1 1 3MHz 3MHz (fXCLK) VDD + VHI X 1 0 1 1 6MHz 3MHz (fXCLK ÷ 2) VDD BLANK (contain $FF) 6MHz 3MHz (fXCLK ÷ 2) Low-voltage entry to monitor mode. 9600 baud communication on PTA0. COP disabled. VDD NOT BLANK 6MHz 3MHz (fXCLK ÷ 2) Enters user mode. If $FFFE and $FFFF is blank, MCU will encounter an illegal address reset. X X X X X X 1 X Comments High-voltage entry to monitor mode. 9600 baud communication on PTA0. COP disabled. Notes: 1. PTA3 = 0: Bypasses the divide-by-two prescaler to SIM when using VDD + VHI for monitor mode entry. 2. See Section 18. Electrical Specifications for VDD + VHI voltage level requirements. Technical Data 166 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Monitor ROM (MON) Freescale Semiconductor Monitor ROM (MON) Functional Description If VDD +VHI is applied to IRQ and PTA3 is low upon monitor mode entry (Table 10-1 condition set 1), the bus frequency is a equal to the external clock, fXCLK. If PTA3 is high with VDD +VHI applied to IRQ upon monitor mode entry (Table 10-1 condition set 2), the bus frequency is a divideby-two of the external clock. Holding the PTA3 pin low when entering monitor mode causes a bypass of a divide-by-two stage at the oscillator only if VDD +VHI is applied to IRQ. In this event, the OSCOUT frequency is equal to the OSCXCLK frequency. Entering monitor mode with VDD + VHI on IRQ, the COP is disabled as long as VDD + VHI is applied to either the IRQ or the RST. (See Section 8. System Integration Module (SIM) for more information on modes of operation.) If entering monitor mode without high voltage on IRQ and reset vector being blank ($FFFE and $FFFF) (Table 10-1 condition set 3, where IRQ applied voltage is VDD), then all port A pin requirements and conditions, including the PTA3 frequency divisor selection, are not in effect. This is to reduce circuit requirements when performing in-circuit programming. Entering monitor mode with the reset vector being blank, the COP is always disabled regardless of the state of IRQ or the RST. Figure 10-2. shows a simplified diagram of the monitor mode entry when the reset vector is blank and IRQ = VDD. An external clock of 6MHz is required for a baud rate of 9600. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Monitor ROM (MON) Technical Data 167 Monitor ROM (MON) POR RESET IS VECTOR BLANK? NO NORMAL USER MODE YES MONITOR MODE EXECUTE MONITOR CODE POR TRIGGERED? NO YES Figure 10-2. Low-Voltage Monitor Mode Entry Flowchart Enter monitor mode with the pin configuration shown above by pulling RST low and then high. The rising edge of RST latches monitor mode. Once monitor mode is latched, the values on the specified pins can change. Once out of reset, the MCU waits for the host to send eight security bytes. (See 10.5 Security.) After the security bytes, the MCU sends a break signal (10 consecutive logic zeros) to the host, indicating that it is ready to receive a command. The break signal also provides a timing reference to allow the host to determine the necessary baud rate. In monitor mode, the MCU uses different vectors for reset, SWI, and break interrupt. The alternate vectors are in the $FE page instead of the $FF page and allow code execution from the internal monitor firmware instead of user code. Technical Data 168 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Monitor ROM (MON) Freescale Semiconductor Monitor ROM (MON) Functional Description Table 10-2 is a summary of the vector differences between user mode and monitor mode. Table 10-2. Monitor Mode Vector Differences Functions COP Reset Vector High Reset Vector Low Break Vector High Break Vector Low SWI Vector High SWI Vector Low User Enabled $FFFE $FFFF $FFFC $FFFD $FFFC $FFFD Monitor Disabled(1) $FEFE $FEFF $FEFC $FEFD $FEFC $FEFD Modes Notes: 1. If the high voltage (VDD + VHI) is removed from the IRQ pin or the RST pin, the SIM asserts its COP enable output. The COP is a mask option enabled or disabled by the COPD bit in the configuration register. When the host computer has completed downloading code into the MCU RAM, the host then sends a RUN command, which executes an RTI, which sends control to the address on the stack pointer. 10.4.2 Baud Rate The communication baud rate is dependant on oscillator frequency, fXCLK. The state of PTA3 also affects baud rate if entry to monitor mode is by IRQ = VDD + VHI. When PTA3 is high, the divide by ratio is 625. If the PTA3 pin is at logic zero upon entry into monitor mode, the divide by ratio is 312. Table 10-3. Monitor Baud Rate Selection Monitor Mode Entry By: IRQ = VDD + VHI Blank reset vector, IRQ = VDD Oscillator Clock Frequency, fCLK PTA3 Baud Rate 3 MHz 0 9600 bps 6 MHz 1 9600 bps 3 MHz 1 4800 bps 6 MHz X 9600 bps 3 MHz X 4800 bps MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Monitor ROM (MON) Technical Data 169 Monitor ROM (MON) 10.4.3 Data Format Communication with the monitor ROM is in standard non-return-to-zero (NRZ) mark/space data format. (See Figure 10-3 and Figure 10-4.) START BIT BIT 0 BIT 1 BIT 2 BIT 3 BIT 4 BIT 5 BIT 6 STOP BIT BIT 7 NEXT START BIT Figure 10-3. Monitor Data Format $A5 START BIT BIT 0 BIT 1 BIT 2 BIT 3 BIT 4 BIT 5 BIT 6 BIT 7 BREAK START BIT BIT 0 BIT 1 BIT 2 BIT 3 BIT 4 BIT 5 BIT 6 BIT 7 STOP BIT STOP BIT NEXT START BIT NEXT START BIT Figure 10-4. Sample Monitor Waveforms The data transmit and receive rate can be anywhere from 4800 baud to 28.8k-baud. Transmit and receive baud rates must be identical. 10.4.4 Echoing As shown in Figure 10-5, the monitor ROM immediately echoes each received byte back to the PTA0 pin for error checking. SENT TO MONITOR READ READ ADDR. HIGH ADDR. HIGH ADDR. LOW ECHO ADDR. LOW DATA RESULT Figure 10-5. Read Transaction Any result of a command appears after the echo of the last byte of the command. Technical Data 170 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Monitor ROM (MON) Freescale Semiconductor Monitor ROM (MON) Functional Description 10.4.5 Break Signal A start bit followed by nine low bits is a break signal. (See Figure 10-6.) When the monitor receives a break signal, it drives the PTA0 pin high for the duration of two bits before echoing the break signal. MISSING STOP BIT TWO-STOP-BIT DELAY BEFORE ZERO ECHO 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 Figure 10-6. Break Transaction 10.4.6 Commands The monitor ROM uses the following commands: • READ (read memory) • WRITE (write memory) • IREAD (indexed read) • IWRITE (indexed write) • READSP (read stack pointer) • RUN (run user program) MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Monitor ROM (MON) Technical Data 171 Monitor ROM (MON) Table 10-4. READ (Read Memory) Command Description Read byte from memory Operand Specifies 2-byte address in high byte:low byte order Data Returned Returns contents of specified address Opcode $4A Command Sequence SENT TO MONITOR READ READ ADDR. HIGH ADDR. HIGH ADDR. LOW ADDR. LOW ECHO DATA RESULT Table 10-5. WRITE (Write Memory) Command Description Write byte to memory Operand Specifies 2-byte address in high byte:low byte order; low byte followed by data byte Data Returned None Opcode $49 Command Sequence SENT TO MONITOR WRITE WRITE ADDR. HIGH ADDR. HIGH ADDR. LOW ADDR. LOW DATA DATA ECHO Technical Data 172 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Monitor ROM (MON) Freescale Semiconductor Monitor ROM (MON) Functional Description Table 10-6. IREAD (Indexed Read) Command Description Read next 2 bytes in memory from last address accessed Operand Specifies 2-byte address in high byte:low byte order Data Returned Returns contents of next two addresses Opcode $1A Command Sequence SENT TO MONITOR IREAD IREAD DATA DATA RESULT ECHO Table 10-7. IWRITE (Indexed Write) Command Description Write to last address accessed + 1 Operand Specifies single data byte Data Returned None Opcode $19 Command Sequence SENT TO MONITOR IWRITE IWRITE DATA DATA ECHO NOTE: A sequence of IREAD or IWRITE commands can sequentially access a block of memory over the full 64-Kbyte memory map. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Monitor ROM (MON) Technical Data 173 Monitor ROM (MON) Table 10-8. READSP (Read Stack Pointer) Command Description Reads stack pointer Operand None Data Returned Returns stack pointer in high byte:low byte order Opcode $0C Command Sequence SENT TO MONITOR READSP READSP SP HIGH SP LOW RESULT ECHO Table 10-9. RUN (Run User Program) Command Description Executes RTI instruction Operand None Data Returned None Opcode $28 Command Sequence SENT TO MONITOR RUN RUN ECHO Technical Data 174 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Monitor ROM (MON) Freescale Semiconductor Monitor ROM (MON) Security 10.5 Security A security feature discourages unauthorized reading of FLASH locations while in monitor mode. The host can bypass the security feature at monitor mode entry by sending eight security bytes that match the bytes at locations $FFF6–$FFFD. Locations $FFF6–$FFFD contain userdefined data. NOTE: Do not leave locations $FFF6–$FFFD blank. For security reasons, program locations $FFF6–$FFFD even if they are not used for vectors. During monitor mode entry, the MCU waits after the power-on reset for the host to send the eight security bytes on pin PTA0. If the received bytes match those at locations $FFF6–$FFFD, the host bypasses the security feature and can read all FLASH locations and execute code from FLASH. Security remains bypassed until a power-on reset occurs. If the reset was not a power-on reset, security remains bypassed and security code entry is not required. (See Figure 10-7.) VDD 4096 + 32 OSCXCLK CYCLES RST COMMAND BYTE 8 BYTE 2 BYTE 1 24 BUS CYCLES FROM HOST PTA0 4 BREAK 2 NOTES: 1 = Echo delay, 2 bit times 2 = Data return delay, 2 bit times 4 = Wait 1 bit time before sending next byte. 1 COMMAND ECHO 1 BYTE 8 ECHO BYTE 1 ECHO FROM MCU 1 BYTE 2 ECHO 4 1 Figure 10-7. Monitor Mode Entry Timing MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Monitor ROM (MON) Technical Data 175 Monitor ROM (MON) Upon power-on reset, if the received bytes of the security code do not match the data at locations $FFF6–$FFFD, the host fails to bypass the security feature. The MCU remains in monitor mode, but reading a FLASH location returns an invalid value and trying to execute code from FLASH causes an illegal address reset. After receiving the eight security bytes from the host, the MCU transmits a break character, signifying that it is ready to receive a command. NOTE: The MCU does not transmit a break character until after the host sends the eight security bytes. To determine whether the security code entered is correct, check to see if bit 6 of RAM address $40 is set. If it is, then the correct security code has been entered and FLASH can be accessed. If the security sequence fails, the device should be reset by a power-on reset and brought up in monitor mode to attempt another entry. After failing the security sequence, the FLASH module can also be mass erased by executing an erase routine that was downloaded into internal RAM. The mass erase operation clears the security code locations so that all eight security bytes become $FF (blank). Technical Data 176 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Monitor ROM (MON) Freescale Semiconductor Technical Data — MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 Section 11. Timer Interface Module (TIM) 11.1 Contents 11.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178 11.3 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178 11.4 Pin Name Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178 11.5 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .179 11.5.1 TIM Counter Prescaler . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181 11.5.2 Input Capture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181 11.5.3 Output Compare. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181 11.5.3.1 Unbuffered Output Compare . . . . . . . . . . . . . . . . . . . . . 182 11.5.3.2 Buffered Output Compare . . . . . . . . . . . . . . . . . . . . . . .183 11.5.4 Pulse Width Modulation (PWM) . . . . . . . . . . . . . . . . . . . . . 183 11.5.4.1 Unbuffered PWM Signal Generation . . . . . . . . . . . . . . . 184 11.5.4.2 Buffered PWM Signal Generation . . . . . . . . . . . . . . . . . 185 11.5.4.3 PWM Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186 11.6 Interrupts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .187 11.7 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187 11.7.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .188 11.7.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .188 11.8 TIM During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . 188 11.9 I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189 11.9.1 TIM Clock Pin (PTE0/TCLK) . . . . . . . . . . . . . . . . . . . . . . .189 11.9.2 TIM Channel I/O Pins (PTE1/TCH0:PTE2/TCH1) . . . . . . . 189 11.10 I/O Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189 11.10.1 TIM Status and Control Register . . . . . . . . . . . . . . . . . . . . 190 11.10.2 TIM Counter Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192 11.10.3 TIM Counter Modulo Registers . . . . . . . . . . . . . . . . . . . . . 193 11.10.4 TIM Channel Status and Control Registers . . . . . . . . . . . . 194 11.10.5 TIM Channel Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . 198 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Timer Interface Module (TIM) Technical Data 177 Timer Interface Module (TIM) 11.2 Introduction This section describes the timer interface module (TIM2, Version B). The TIM is a 2-channel timer that provides a timing reference with input capture, output compare, and pulse-width-modulation functions. Figure 11-1 is a block diagram of the TIM. 11.3 Features Features of the TIM include: • Two input capture/output compare channels – Rising-edge, falling-edge, or any-edge input capture trigger – Set, clear, or toggle output compare action • Buffered and unbuffered pulse width modulation (PWM) signal generation • Programmable TIM clock input – 7-frequency internal bus clock prescaler selection – External TIM clock input (bus frequency ÷2 maximum) • Free-running or modulo up-count operation • Toggle any channel pin on overflow • TIM counter stop and reset bits 11.4 Pin Name Conventions The TIM share three I/O pins with three port E I/O pins. The full name of the TIM I/O pin is listed in Table 11-1. The generic pin name appear in the text that follows. Table 11-1. TIM Pin Name Conventions Technical Data 178 TIM Generic Pin Names: TCLK TCH0 TCH1 Full TIM Pin Names: PTE0/TCLK PTE1/TCH0 PTE2/TCH1 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Timer Interface Module (TIM) Freescale Semiconductor Timer Interface Module (TIM) Functional Description 11.5 Functional Description Figure 11-1 shows the structure of the TIM. The central component of the TIM is the 16-bit TIM counter that can operate as a free-running counter or a modulo up-counter. The TIM counter provides the timing reference for the input capture and output compare functions. The TIM counter modulo registers, TMODH:TMODL, control the modulo value of the TIM counter. Software can read the TIM counter value at any time without affecting the counting sequence. The two TIM channels are programmable independently as input capture or output compare channels. TCLK PRESCALER SELECT INTERNAL BUS CLOCK PRESCALER TSTOP PS2 TRST PS1 PS0 16-BIT COUNTER TOF TOIE INTERRUPT LOGIC 16-BIT COMPARATOR TMODH:TMODL TOV0 CHANNEL 0 ELS0B ELS0A CH0MAX 16-BIT COMPARATOR TCH0H:TCH0L PORT LOGIC TCH0 CH0F INTERRUPT LOGIC 16-BIT LATCH MS0A CH0IE MS0B INTERNAL BUS TOV1 CHANNEL 1 ELS1B ELS1A CH1MAX PORT LOGIC TCH1 16-BIT COMPARATOR TCH1H:TCH1L CH1F INTERRUPT LOGIC 16-BIT LATCH MS1A CH1IE Figure 11-1. TIM Block Diagram MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Timer Interface Module (TIM) Technical Data 179 Timer Interface Module (TIM) Addr. $000A $000C $000D Register Name TIM Status and Control Register (TSC) TIM Counter Register High (TCNTH) TIM Counter Register Low (TCNTL) Bit 7 Read: $000E TIM Counter Modulo Register Low (TMODL) $000F $0010 TIM Channel 0 Status and Control Register (TSC0) TIM Channel 0 Register High (TCH0H) $0011 TIM Channel 0 Register Low (TCH0L) $0012 $0013 TIM Channel 1 Status and Control Register (TSC1) 5 TOIE TSTOP TOF 4 3 0 0 2 1 Bit 0 PS2 PS1 PS0 Write: 0 Reset: 0 0 1 0 0 0 0 0 Read: Bit15 Bit14 Bit13 Bit12 Bit11 Bit10 Bit9 Bit8 TRST Reset: 0 0 0 0 0 0 0 0 Read: Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 0 0 0 0 0 0 0 0 Bit15 Bit14 Bit13 Bit12 Bit11 Bit10 Bit9 Bit8 1 1 1 1 1 1 1 1 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 Reset: 1 1 1 1 1 1 1 1 Read: CH0F CH0IE MS0B MS0A ELS0B ELS0A TOV0 CH0MAX Write: 0 Reset: 0 0 0 0 0 0 0 0 Bit15 Bit14 Bit13 Bit12 Bit11 Bit10 Bit9 Bit8 Bit2 Bit1 Bit0 Write: Write: Reset: TIM Counter Modulo Register High (TMODH) 6 Read: Write: Reset: Read: Write: Read: Write: Reset: Indeterminate after reset Read: Bit7 Bit6 Bit5 Bit4 Bit3 Write: Reset: Read: Indeterminate after reset CH1F 0 CH1IE Write: 0 Reset: 0 0 MS1A ELS1B ELS1A TOV1 CH1MAX 0 0 0 0 0 0 = Unimplemented Figure 11-2. TIM I/O Register Summary Technical Data 180 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Timer Interface Module (TIM) Freescale Semiconductor Timer Interface Module (TIM) Functional Description $0014 $0015 TIM Channel 1 Register High (TCH1H) TIM Channel 1 Register Low (TCH1L) Read: Bit15 Bit14 Bit13 Bit12 Bit11 Bit10 Bit9 Bit8 Bit2 Bit1 Bit0 Write: Reset: Indeterminate after reset Read: Bit7 Bit6 Bit5 Bit4 Bit3 Write: Reset: Indeterminate after reset = Unimplemented Figure 11-2. TIM I/O Register Summary 11.5.1 TIM Counter Prescaler The TIM clock source can be one of the seven prescaler outputs or the TIM clock pin, PTE0/TCLK. The prescaler generates seven clock rates from the internal bus clock. The prescaler select bits, PS[2:0], in the TIM status and control register (TSC) select the TIM clock source. 11.5.2 Input Capture With the input capture function, the TIM can capture the time at which an external event occurs. When an active edge occurs on the pin of an input capture channel, the TIM latches the contents of the TIM counter into the TIM channel registers, TCHxH:TCHxL. The polarity of the active edge is programmable. Input captures can generate TIM CPU interrupt requests. 11.5.3 Output Compare With the output compare function, the TIM can generate a periodic pulse with a programmable polarity, duration, and frequency. When the counter reaches the value in the registers of an output compare channel, the TIM can set, clear, or toggle the channel pin. Output compares can generate TIM CPU interrupt requests. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Timer Interface Module (TIM) Technical Data 181 Timer Interface Module (TIM) 11.5.3.1 Unbuffered Output Compare Any output compare channel can generate unbuffered output compare pulses as described in 11.5.3 Output Compare. The pulses are unbuffered because changing the output compare value requires writing the new value over the old value currently in the TIM channel registers. An unsynchronized write to the TIM channel registers to change an output compare value could cause incorrect operation for up to two counter overflow periods. For example, writing a new value before the counter reaches the old value but after the counter reaches the new value prevents any compare during that counter overflow period. Also, using a TIM overflow interrupt routine to write a new, smaller output compare value may cause the compare to be missed. The TIM may pass the new value before it is written. Use the following methods to synchronize unbuffered changes in the output compare value on channel x: Technical Data 182 • When changing to a smaller value, enable channel x output compare interrupts and write the new value in the output compare interrupt routine. The output compare interrupt occurs at the end of the current output compare pulse. The interrupt routine has until the end of the counter overflow period to write the new value. • When changing to a larger output compare value, enable TIM overflow interrupts and write the new value in the TIM overflow interrupt routine. The TIM overflow interrupt occurs at the end of the current counter overflow period. Writing a larger value in an output compare interrupt routine (at the end of the current pulse) could cause two output compares to occur in the same counter overflow period. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Timer Interface Module (TIM) Freescale Semiconductor Timer Interface Module (TIM) Functional Description 11.5.3.2 Buffered Output Compare Channels 0 and 1 can be linked to form a buffered output compare channel whose output appears on the PTE1/TCH0 pin. The TIM channel registers of the linked pair alternately control the output. Setting the MS0B bit in TIM channel 0 status and control register (TSC0) links channel 0 and channel 1. The output compare value in the TIM channel 0 registers initially controls the output on the PTE1/TCH0 pin. Writing to the TIM channel 1 registers enables the TIM channel 1 registers to synchronously control the output after the TIM overflows. At each subsequent overflow, the TIM channel registers (0 or 1) that control the output are the ones written to last. TSC0 controls and monitors the buffered output compare function, and TIM channel 1 status and control register (TSC1) is unused. While the MS0B bit is set, the channel 1 pin, PTE2/TCH1, is available as a general-purpose I/O pin. NOTE: In buffered output compare operation, do not write new output compare values to the currently active channel registers. User software should track the currently active channel to prevent writing a new value to the active channel. Writing to the active channel registers is the same as generating unbuffered output compares. 11.5.4 Pulse Width Modulation (PWM) By using the toggle-on-overflow feature with an output compare channel, the TIM can generate a PWM signal. The value in the TIM counter modulo registers determines the period of the PWM signal. The channel pin toggles when the counter reaches the value in the TIM counter modulo registers. The time between overflows is the period of the PWM signal. As Figure 11-3 shows, the output compare value in the TIM channel registers determines the pulse width of the PWM signal. The time between overflow and output compare is the pulse width. Program the TIM to clear the channel pin on output compare if the state of the PWM pulse is logic 1. Program the TIM to set the pin if the state of the PWM pulse is logic 0. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Timer Interface Module (TIM) Technical Data 183 Timer Interface Module (TIM) OVERFLOW OVERFLOW OVERFLOW PERIOD PULSE WIDTH PTEx/TCHxA OUTPUT COMPARE OUTPUT COMPARE OUTPUT COMPARE Figure 11-3. PWM Period and Pulse Width The value in the TIM counter modulo registers and the selected prescaler output determines the frequency of the PWM output. The frequency of an 8-bit PWM signal is variable in 256 increments. Writing $00FF (255) to the TIM counter modulo registers produces a PWM period of 256 times the internal bus clock period if the prescaler select value is 000 (see 11.10.1 TIM Status and Control Register). The value in the TIM channel registers determines the pulse width of the PWM output. The pulse width of an 8-bit PWM signal is variable in 256 increments. Writing $0080 (128) to the TIM channel registers produces a duty cycle of 128/256 or 50%. 11.5.4.1 Unbuffered PWM Signal Generation Any output compare channel can generate unbuffered PWM pulses as described in 11.5.4 Pulse Width Modulation (PWM). The pulses are unbuffered because changing the pulse width requires writing the new pulse width value over the old value currently in the TIM channel registers. An unsynchronized write to the TIM channel registers to change a pulse width value could cause incorrect operation for up to two PWM periods. For example, writing a new value before the counter reaches the old value but after the counter reaches the new value prevents any compare during that PWM period. Also, using a TIM overflow interrupt routine to write a new, smaller pulse width value may cause the compare to be missed. The TIM may pass the new value before it is written. Technical Data 184 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Timer Interface Module (TIM) Freescale Semiconductor Timer Interface Module (TIM) Functional Description Use the following methods to synchronize unbuffered changes in the PWM pulse width on channel x: NOTE: • When changing to a shorter pulse width, enable channel x output compare interrupts and write the new value in the output compare interrupt routine. The output compare interrupt occurs at the end of the current pulse. The interrupt routine has until the end of the PWM period to write the new value. • When changing to a longer pulse width, enable TIM overflow interrupts and write the new value in the TIM overflow interrupt routine. The TIM overflow interrupt occurs at the end of the current PWM period. Writing a larger value in an output compare interrupt routine (at the end of the current pulse) could cause two output compares to occur in the same PWM period. In PWM signal generation, do not program the PWM channel to toggle on output compare. Toggling on output compare prevents reliable 0% duty cycle generation and removes the ability of the channel to selfcorrect in the event of software error or noise. Toggling on output compare also can cause incorrect PWM signal generation when changing the PWM pulse width to a new, much larger value. 11.5.4.2 Buffered PWM Signal Generation Channels 0 and 1 can be linked to form a buffered PWM channel whose output appears on the PTE1/TCH0 pin. The TIM channel registers of the linked pair alternately control the pulse width of the output. Setting the MS0B bit in TIM channel 0 status and control register (TSC0) links channel 0 and channel 1. The TIM channel 0 registers initially control the pulse width on the PTE1/TCH0 pin. Writing to the TIM channel 1 registers enables the TIM channel 1 registers to synchronously control the pulse width at the beginning of the next PWM period. At each subsequent overflow, the TIM channel registers (0 or 1) that control the pulse width are the ones written to last. TSC0 controls and monitors the buffered PWM function, and TIM channel 1 status and control register (TSC1) is unused. While the MS0B bit is set, the channel 1 pin, PTE2/TCH1, is available as a general-purpose I/O pin. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Timer Interface Module (TIM) Technical Data 185 Timer Interface Module (TIM) NOTE: In buffered PWM signal generation, do not write new pulse width values to the currently active channel registers. User software should track the currently active channel to prevent writing a new value to the active channel. Writing to the active channel registers is the same as generating unbuffered PWM signals. 11.5.4.3 PWM Initialization To ensure correct operation when generating unbuffered or buffered PWM signals, use this initialization procedure: 1. In the TIM status and control register (TSC): a. Stop the TIM counter by setting the TIM stop bit, TSTOP. b. Reset the TIM counter and prescaler by setting the TIM reset bit, TRST. 2. In the TIM counter modulo registers (TMODH:TMODL), write the value for the required PWM period. 3. In the TIM channel x registers (TCHxH:TCHxL), write the value for the required pulse width. 4. In TIM channel x status and control register (TSCx): a. Write 0:1 (for unbuffered output compare or PWM signals) or 1:0 (for buffered output compare or PWM signals) to the mode select bits, MSxB:MSxA. (See Table 11-3.) b. Write 1 to the toggle-on-overflow bit, TOVx. c. Write 1:0 (to clear output on compare) or 1:1 (to set output on compare) to the edge/level select bits, ELSxB:ELSxA. The output action on compare must force the output to the complement of the pulse width level. (See Table 11-3.) NOTE: In PWM signal generation, do not program the PWM channel to toggle on output compare. Toggling on output compare prevents reliable 0% duty cycle generation and removes the ability of the channel to selfcorrect in the event of software error or noise. Toggling on output compare can also cause incorrect PWM signal generation when changing the PWM pulse width to a new, much larger value. 5. In the TIM status control register (TSC), clear the TIM stop bit, TSTOP. Technical Data 186 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Timer Interface Module (TIM) Freescale Semiconductor Timer Interface Module (TIM) Interrupts Setting MS0B links channels 0 and 1 and configures them for buffered PWM operation. The TIM channel 0 registers (TCH0H:TCH0L) initially control the buffered PWM output. TIM status control register 0 (TSCR0) controls and monitors the PWM signal from the linked channels. MS0B takes priority over MS0A. Clearing the toggle-on-overflow bit, TOVx, inhibits output toggles on TIM overflows. Subsequent output compares try to force the output to a state it is already in and have no effect. The result is a 0% duty cycle output. Setting the channel x maximum duty cycle bit (CHxMAX) and setting the TOVx bit generates a 100% duty cycle output. (See 11.10.4 TIM Channel Status and Control Registers.) 11.6 Interrupts The following TIM sources can generate interrupt requests: • TIM overflow flag (TOF) — The TOF bit is set when the TIM counter reaches the modulo value programmed in the TIM counter modulo registers. The TIM overflow interrupt enable bit, TOIE, enables TIM overflow CPU interrupt requests. TOF and TOIE are in the TIM status and control register. • TIM channel flags (CH1F:CH0F) — The CHxF bit is set when an input capture or output compare occurs on channel x. Channel x TIM CPU interrupt requests are controlled by the channel x interrupt enable bit, CHxIE. Channel x TIM CPU interrupt requests are enabled when CHxIE = 1. CHxF and CHxIE are in the TIM channel x status and control register. 11.7 Low-Power Modes The WAIT and STOP instructions put the MCU in low powerconsumption standby modes. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Timer Interface Module (TIM) Technical Data 187 Timer Interface Module (TIM) 11.7.1 Wait Mode The TIM remains active after the execution of a WAIT instruction. In wait mode the TIM registers are not accessible by the CPU. Any enabled CPU interrupt request from the TIM can bring the MCU out of wait mode. If TIM functions are not required during wait mode, reduce power consumption by stopping the TIM before executing the WAIT instruction. 11.7.2 Stop Mode The TIM is inactive after the execution of a STOP instruction. The STOP instruction does not affect register conditions or the state of the TIM counter. TIM operation resumes when the MCU exits stop mode after an external interrupt. 11.8 TIM During Break Interrupts A break interrupt stops the TIM counter. The system integration module (SIM) controls whether status bits in other modules can be cleared during the break state. The BCFE bit in the break flag control register (BFCR) enables software to clear status bits during the break state. (See 8.8.3 Break Flag Control Register.) To allow software to clear status bits during a break interrupt, write a logic 1 to the BCFE bit. If a status bit is cleared during the break state, it remains cleared when the MCU exits the break state. To protect status bits during the break state, write a logic 0 to the BCFE bit. With BCFE at logic 0 (its default state), software can read and write I/O registers during the break state without affecting status bits. Some status bits have a 2-step read/write clearing procedure. If software does the first step on such a bit before the break, the bit cannot change during the break state as long as BCFE is at logic 0. After the break, doing the second step clears the status bit. Technical Data 188 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Timer Interface Module (TIM) Freescale Semiconductor Timer Interface Module (TIM) I/O Signals 11.9 I/O Signals Port E shares three of its pins with the TIM. PTE0/TCLK is an external clock input to the TIM prescaler. The two TIM channel I/O pins are PTE1/TCH0 and PTE2/TCH1. 11.9.1 TIM Clock Pin (PTE0/TCLK) PTE0/TCLK is an external clock input that can be the clock source for the TIM counter instead of the prescaled internal bus clock. Select the PTE0/TCLK input by writing logic 1s to the three prescaler select bits, PS[2:0]. (See 11.10.1 TIM Status and Control Register.) The minimum TCLK pulse width, TCLKLMIN or TCLKHMIN, is: 1 ------------------------------------- + t SU bus frequency The maximum TCLK frequency is: bus frequency ÷ 2 PTE0/TCLK is available as a general-purpose I/O pin when not used as the TIM clock input. When the PTE0/TCLK pin is the TIM clock input, it is an input regardless of the state of the DDRE0 bit in data direction register E. 11.9.2 TIM Channel I/O Pins (PTE1/TCH0:PTE2/TCH1) Each channel I/O pin is programmable independently as an input capture pin or an output compare pin. PTE1/TCH0 can be configured as buffered output compare or buffered PWM pins. 11.10 I/O Registers The following I/O registers control and monitor operation of the TIM: • TIM status and control register (TSC) • TIM counter registers (TCNTH:TCNTL) • TIM counter modulo registers (TMODH:TMODL) • TIM channel status and control registers (TSC0 and TSC1) • TIM channel registers (TCH0H:TCH0L and TCH1H:TCH1L) MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Timer Interface Module (TIM) Technical Data 189 Timer Interface Module (TIM) 11.10.1 TIM Status and Control Register The TIM status and control register: • Enables TIM overflow interrupts • Flags TIM overflows • Stops the TIM counter • Resets the TIM counter • Prescales the TIM counter clock Address: $000A Bit 7 Read: 6 5 TOIE TSTOP TOF Write: 0 Reset: 0 4 3 0 0 2 1 Bit 0 PS2 PS1 PS0 0 0 0 TRST 0 1 0 0 = Unimplemented Figure 11-4. TIM Status and Control Register (TSC) TOF — TIM Overflow Flag Bit This read/write flag is set when the TIM counter reaches the modulo value programmed in the TIM counter modulo registers. Clear TOF by reading the TIM status and control register when TOF is set and then writing a logic 0 to TOF. If another TIM overflow occurs before the clearing sequence is complete, then writing logic 0 to TOF has no effect. Therefore, a TOF interrupt request cannot be lost due to inadvertent clearing of TOF. Reset clears the TOF bit. Writing a logic 1 to TOF has no effect. 1 = TIM counter has reached modulo value 0 = TIM counter has not reached modulo value TOIE — TIM Overflow Interrupt Enable Bit This read/write bit enables TIM overflow interrupts when the TOF bit becomes set. Reset clears the TOIE bit. 1 = TIM overflow interrupts enabled 0 = TIM overflow interrupts disabled Technical Data 190 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Timer Interface Module (TIM) Freescale Semiconductor Timer Interface Module (TIM) I/O Registers TSTOP — TIM Stop Bit This read/write bit stops the TIM counter. Counting resumes when TSTOP is cleared. Reset sets the TSTOP bit, stopping the TIM counter until software clears the TSTOP bit. 1 = TIM counter stopped 0 = TIM counter active NOTE: Do not set the TSTOP bit before entering wait mode if the TIM is required to exit wait mode. TRST — TIM Reset Bit Setting this write-only bit resets the TIM counter and the TIM prescaler. Setting TRST has no effect on any other registers. Counting resumes from $0000. TRST is cleared automatically after the TIM counter is reset and always reads as logic 0. Reset clears the TRST bit. 1 = Prescaler and TIM counter cleared 0 = No effect NOTE: Setting the TSTOP and TRST bits simultaneously stops the TIM counter at a value of $0000. PS[2:0] — Prescaler Select Bits These read/write bits select either the PTE0/TCLK pin or one of the seven prescaler outputs as the input to the TIM counter as Table 11-2 shows. Reset clears the PS[2:0] bits. Table 11-2. Prescaler Selection PS2 PS1 PS0 TIM Clock Source 0 0 0 Internal Bus Clock ÷1 0 0 1 Internal Bus Clock ÷ 2 0 1 0 Internal Bus Clock ÷ 4 0 1 1 Internal Bus Clock ÷ 8 1 0 0 Internal Bus Clock ÷ 16 1 0 1 Internal Bus Clock ÷ 32 1 1 0 Internal Bus Clock ÷ 64 1 1 1 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Timer Interface Module (TIM) PTE0/TCLK Technical Data 191 Timer Interface Module (TIM) 11.10.2 TIM Counter Registers The two read-only TIM counter registers contain the high and low bytes of the value in the TIM counter. Reading the high byte (TCNTH) latches the contents of the low byte (TCNTL) into a buffer. Subsequent reads of TCNTH do not affect the latched TCNTL value until TCNTL is read. Reset clears the TIM counter registers. Setting the TIM reset bit (TRST) also clears the TIM counter registers. NOTE: If you read TCNTH during a break interrupt, be sure to unlatch TCNTL by reading TCNTL before exiting the break interrupt. Otherwise, TCNTL retains the value latched during the break. TCNTH Read: Address: $000C Bit 7 6 5 4 3 2 1 Bit 0 Bit 15 Bit 14 Bit 13 Bit 12 Bit 11 Bit 10 Bit 9 Bit 8 0 0 0 0 0 0 0 0 Write: Reset: TCNTL Read: Address: $000D Bit 7 6 5 4 3 2 1 Bit 0 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 0 0 0 0 0 0 0 0 Write: Reset: = Unimplemented Figure 11-5. TIM Counter Registers (TCNTH:TCNTL) Technical Data 192 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Timer Interface Module (TIM) Freescale Semiconductor Timer Interface Module (TIM) I/O Registers 11.10.3 TIM Counter Modulo Registers The read/write TIM modulo registers contain the modulo value for the TIM counter. When the TIM counter reaches the modulo value, the overflow flag (TOF) becomes set, and the TIM counter resumes counting from $0000 at the next timer clock. Writing to the high byte (TMODH) inhibits the TOF bit and overflow interrupts until the low byte (TMODL) is written. Reset sets the TIM counter modulo registers. TMODH Address: $000E Bit 7 6 5 4 3 2 1 Bit 0 Bit 15 Bit 14 Bit 13 Bit 12 Bit 11 Bit 10 Bit 9 Bit 8 1 1 1 1 1 1 1 1 Read: Write: Reset: TMODL Address: $000F Bit 7 6 5 4 3 2 1 Bit 0 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 1 1 1 1 1 1 1 1 Read: Write: Reset: Figure 11-6. TIM Counter Modulo Registers (TMODH:TMODL) NOTE: Reset the TIM counter before writing to the TIM counter modulo registers. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Timer Interface Module (TIM) Technical Data 193 Timer Interface Module (TIM) 11.10.4 TIM Channel Status and Control Registers Each of the TIM channel status and control registers does the following: • Flags input captures and output compares • Enables input capture and output compare interrupts • Selects input capture, output compare, or PWM operation • Selects high, low, or toggling output on output compare • Selects rising edge, falling edge, or any edge as the active input capture trigger • Selects output toggling on TIM overflow • Selects 0% and 100% PWM duty cycle • Selects buffered or unbuffered output compare/PWM operation TSC0 Address: $0010 Bit 7 Read: CH0F Write: 0 Reset: 0 TSC1 5 4 3 2 1 Bit 0 CH0IE MS0B MS0A ELS0B ELS0A TOV0 CH0MAX 0 0 0 0 0 0 0 5 4 3 2 1 Bit 0 MS1A ELS1B ELS1A TOV1 CH1MAX 0 0 0 0 0 Address: $0013 Bit 7 Read: 6 6 CH1F 0 CH1IE Write: 0 Reset: 0 0 0 = Unimplemented Figure 11-7. TIM Channel Status and Control Registers (TSC0:TSC1) Technical Data 194 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Timer Interface Module (TIM) Freescale Semiconductor Timer Interface Module (TIM) I/O Registers CHxF — Channel x Flag Bit When channel x is an input capture channel, this read/write bit is set when an active edge occurs on the channel x pin. When channel x is an output compare channel, CHxF is set when the value in the TIM counter registers matches the value in the TIM channel x registers. When TIM CPU interrupt requests are enabled (CHxIE = 1), clear CHxF by reading the TIM channel x status and control register with CHxF set and then writing a logic 0 to CHxF. If another interrupt request occurs before the clearing sequence is complete, then writing logic 0 to CHxF has no effect. Therefore, an interrupt request cannot be lost due to inadvertent clearing of CHxF. Reset clears the CHxF bit. Writing a logic 1 to CHxF has no effect. 1 = Input capture or output compare on channel x 0 = No input capture or output compare on channel x CHxIE — Channel x Interrupt Enable Bit This read/write bit enables TIM CPU interrupt service requests on channel x. Reset clears the CHxIE bit. 1 = Channel x CPU interrupt requests enabled 0 = Channel x CPU interrupt requests disabled MSxB — Mode Select Bit B This read/write bit selects buffered output compare/PWM operation. MSxB exists only in the TIM channel 0 status and control register. Setting MS0B disables the channel 1 status and control register and reverts TCH1 to general-purpose I/O. Reset clears the MSxB bit. 1 = Buffered output compare/PWM operation enabled 0 = Buffered output compare/PWM operation disabled MSxA — Mode Select Bit A When ELSxB:ELSxA ≠ 0:0, this read/write bit selects either input capture operation or unbuffered output compare/PWM operation. See Table 11-3. 1 = Unbuffered output compare/PWM operation 0 = Input capture operation MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Timer Interface Module (TIM) Technical Data 195 Timer Interface Module (TIM) When ELSxB:ELSxA = 0:0, this read/write bit selects the initial output level of the TCHx pin. (See Table 11-3.) Reset clears the MSxA bit. 1 = Initial output level low 0 = Initial output level high NOTE: Before changing a channel function by writing to the MSxB or MSxA bit, set the TSTOP and TRST bits in the TIM status and control register (TSC). ELSxB and ELSxA — Edge/Level Select Bits When channel x is an input capture channel, these read/write bits control the active edge-sensing logic on channel x. When channel x is an output compare channel, ELSxB and ELSxA control the channel x output behavior when an output compare occurs. When ELSxB and ELSxA are both clear, channel x is not connected to port E, and pin PTEx/TCHx is available as a general-purpose I/O pin. Table 11-3 shows how ELSxB and ELSxA work. Reset clears the ELSxB and ELSxA bits. Table 11-3. Mode, Edge, and Level Selection Technical Data 196 MSxB MSxA ELSxB ELSxA X 0 0 0 X 1 0 0 0 0 0 1 0 0 1 0 0 0 1 1 0 1 0 1 0 1 1 0 0 1 1 1 1 X 0 1 1 X 1 0 1 X 1 1 Mode Output Preset Configuration Pin under port control; initial output level high Pin under port control; initial output level low Capture on rising edge only Input Capture Capture on falling edge only Capture on rising or falling edge Output Compare or PWM Toggle output on compare Clear output on compare Set output on compare Toggle output on compare Buffered Output Clear output on compare Compare or Buffered Set output on compare PWM MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Timer Interface Module (TIM) Freescale Semiconductor Timer Interface Module (TIM) I/O Registers NOTE: Before enabling a TIM channel register for input capture operation, make sure that the PTEx/TCHx pin is stable for at least two bus clocks. TOVx — Toggle-On-Overflow Bit When channel x is an output compare channel, this read/write bit controls the behavior of the channel x output when the TIM counter overflows. When channel x is an input capture channel, TOVx has no effect. Reset clears the TOVx bit. 1 = Channel x pin toggles on TIM counter overflow 0 = Channel x pin does not toggle on TIM counter overflow NOTE: When TOVx is set, a TIM counter overflow takes precedence over a channel x output compare if both occur at the same time. CHxMAX — Channel x Maximum Duty Cycle Bit When the TOVx bit is at logic 1, setting the CHxMAX bit forces the duty cycle of buffered and unbuffered PWM signals to 100%. As Figure 11-8 shows, the CHxMAX bit takes effect in the cycle after it is set or cleared. The output stays at the 100% duty cycle level until the cycle after CHxMAX is cleared. OVERFLOW OVERFLOW OVERFLOW OVERFLOW OVERFLOW PERIOD PTEx/TCHx OUTPUT COMPARE OUTPUT COMPARE OUTPUT COMPARE OUTPUT COMPARE CHxMAX Figure 11-8. CHxMAX Latency MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Timer Interface Module (TIM) Technical Data 197 Timer Interface Module (TIM) 11.10.5 TIM Channel Registers These read/write registers contain the captured TIM counter value of the input capture function or the output compare value of the output compare function. The state of the TIM channel registers after reset is unknown. In input capture mode (MSxB:MSxA = 0:0), reading the high byte of the TIM channel x registers (TCHxH) inhibits input captures until the low byte (TCHxL) is read. In output compare mode (MSxB:MSxA ≠ 0:0), writing to the high byte of the TIM channel x registers (TCHxH) inhibits output compares until the low byte (TCHxL) is written. TCH0H Read: Write: Address: $0011 Bit 7 6 5 4 3 2 1 Bit 0 Bit 15 Bit 14 Bit 13 Bit 12 Bit 11 Bit 10 Bit 9 Bit 8 Reset: TCH0L Read: Write: Indeterminate after reset Address: $0012 Bit 7 6 5 4 3 2 1 Bit 0 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset: TCH1H Read: Write: Indeterminate after reset Address: $0014 Bit 7 6 5 4 3 2 1 Bit 0 Bit 15 Bit 14 Bit 13 Bit 12 Bit 11 Bit 10 Bit 9 Bit 8 Reset: TCH1L Read: Write: Reset: Indeterminate after reset Address: $0015 Bit 7 6 5 4 3 2 1 Bit 0 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Indeterminate after reset Figure 11-9. TIM Channel Registers (TCH0H/L:TCH1H/L) Technical Data 198 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Timer Interface Module (TIM) Freescale Semiconductor Technical Data — MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 Section 12. Input/Output Ports (I/O) 12.1 Contents 12.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199 12.3 Port A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202 12.3.1 Port A Data Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202 12.3.2 Data Direction Register A. . . . . . . . . . . . . . . . . . . . . . . . . . 203 12.4 Port B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204 12.4.1 Port B Data Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204 12.4.2 Data Direction Register B. . . . . . . . . . . . . . . . . . . . . . . . . . 205 12.5 Port C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207 12.5.1 Port C Data Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207 12.5.2 Data Direction Register C. . . . . . . . . . . . . . . . . . . . . . . . . . 208 12.6 Port D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209 12.6.1 Port D Data Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210 12.6.2 Data Direction Register D. . . . . . . . . . . . . . . . . . . . . . . . . . 211 12.7 Port E . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212 12.7.1 Port E Data Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213 12.7.2 Data Direction Register E. . . . . . . . . . . . . . . . . . . . . . . . . . 215 12.8 Port Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216 12.8.1 Port Option Control Register . . . . . . . . . . . . . . . . . . . . . . .217 12.2 Introduction Thirty-seven (37) bidirectional input-output (I/O) pins form five parallel ports. All I/O pins are programmable as inputs or outputs. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Input/Output Ports (I/O) Technical Data 199 Input/Output Ports (I/O) NOTE: Connect any unused I/O pins to an appropriate logic level, either VREG or VSS. Although the I/O ports do not require termination for proper operation, termination reduces excess current consumption and the possibility of electrostatic damage. Addr. Register Name Bit 7 6 5 4 3 2 1 Bit 0 $0000 Port A Data Register Read: (PTA) Write: PTA7 PTA6 PTA5 PTA4 PTA3 PTA2 PTA1 PTA0 PTB2 PTB1 PTB0 PTC2 PTC1 PTC0 PTD2 PTD1 PTD0 Reset: $0001 Port B Data Register Read: (PTB) Write: Unaffected by reset PTB7 PTB6 PTB5 Reset: $0002 Port C Data Register Read: (PTC) Write: Port D Data Register Read: (PTD) Write: PTC7 PTC6 PTC5 PTC4 PTC3 Unaffected by reset PTD7 PTD6 PTD5 Reset: PTD4 PTD3 Unaffected by reset $0004 Data Direction Register A Read: DDRA7 (DDRA) Write: Reset: PTB3 Unaffected by reset Reset: $0003 PTB4 0* DDRA6 DDRA5 DDRA4 DDRA3 DDRA2 DDRA1 DDRA0 0 0 0 0 0 0 0 DDRB6 DDRB5 DDRB4 DDRB3 DDRB2 DDRB1 DDRB0 0 0 0 0 0 0 0 DDRC6 DDRC5 DDRC4 DDRC3 DDRC2 DDRC1 DDRC0 0 0 0 0 0 0 0 DDRD6 DDRD5 DDRD4 DDRD3 DDRD2 DDRD1 DDRD0 0 0 0 0 0 PTE4 PTE3 PTE2 PTE1 PTE0 * DDRA7 bit is reset by POR or LVI reset only. $0005 Data Direction Register B Read: DDRB7 (DDRB) Write: Reset: 0 $0006 Data Direction Register C Read: DDRC7 (DDRC) Write: Reset: 0 $0007 Data Direction Register D Read: DDRD7 (DDRD) Write: $0008 Reset: 0 0 0 Port E Data Register Read: (PTE) Write: 0 0 0 Reset: Unaffected by reset = Unimplemented Figure 12-1. I/O Port Register Summary Technical Data 200 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Input/Output Ports (I/O) Freescale Semiconductor Input/Output Ports (I/O) Introduction Addr. Register Name Bit 7 6 5 $0009 Data Direction Register E Read: (DDRE) Write: 0 0 0 Reset: 0 0 0 $001D Read: Port Option Control PTE20P Register Write: (POCR) Reset: 0 PTDLDD PTDILDD 0 4 3 2 1 Bit 0 DDRE4 DDRE3 DDRE2 DDRE1 DDRE0 0 0 0 0 0 PTE4P PTE3P PCP PBP PAP 0 0 0 0 0 0 = Unimplemented Figure 12-1. I/O Port Register Summary Table 12-1. Port Control Register Bits Summary Port Module Control Bit DDR 0 DDRA0 KBIE0 PTA0/KBA0 1 DDRA1 KBIE1 PTA1/KBA1 2 DDRA2 KBIE2 PTA2/KBA2 3 DDRA3 KBIE3 PTA3/KBA3 A Module KBI Register Control Bit Pin KBIER ($0017) 4 DDRA4 KBIE4 PTA4/KBA4 5 DDRA5 KBIE5 PTA5/KBA5 6 DDRA6 KBIE6 PTA6/KBA6 7 DDRA7 KBIE7 PTA7/KBA7 B 0–7 DDRB[0:7] — — — PTB0–PTB7 C 0–7 DDRC[0:7] — — — PTC0–PTC7 D 0–7 DDRD[0:7] — — — PTD0–PTD7 0 DDRE0 TSC ($000A) PS[2:0] PTE0/TCLK 1 DDRE1 TSC0 ($0010) ELS0B:ELS0A PTE1/TCH0 2 DDRE2 TSC1 ($0013) ELS1B:ELS1A PTE2/TCH1 3 DDRE3 UADDR ($0038) USBEN E TIM PTE3/D+ USB 4 DDRE4 PTE4/D– MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Input/Output Ports (I/O) Technical Data 201 Input/Output Ports (I/O) 12.3 Port A Port A is an 8-bit general-purpose bidirectional I/O port with software configurable pullups, and it shares its pins with the keyboard interrupt module (KBI). 12.3.1 Port A Data Register The port A data register contains a data latch for each of the eight port A pins. Address: $0000 Bit 7 6 5 4 3 2 1 Bit 0 PTA7 PTA6 PTA5 PTA4 PTA3 PTA2 PTA1 PTA0 Read: Write: Reset: Alternativ e Function: Unaffected by reset KBA7 Additional Optional Function: pullup KBA6 KBA5 KBA4 KBA3 KBA2 KBA1 KBA0 Optional pullup Optional pullup Optional pullup Optional pullup Optional pullup Optional pullup Optional pullup Figure 12-2. Port A Data Register (PTA) PTA[7:0] — Port A Data Bits These read/write bits are software programmable. Data direction of each port A pin is under the control of the corresponding bit in data direction register A. Reset has no effect on port A data. The port A pullup enable bit, PAP, in the port option control register (POCR) enables pullups on port A pins if the respective pin is configured as an input. (See 12.8 Port Options.) KBA7–KBA0 — Keyboard Interrupts The keyboard interrupt enable bits, KBIE7–KBIE0, in the keyboard interrupt enable register (KBIER), enable the port A pins as external interrupt pins. (See Section 14. Keyboard Interrupt Module (KBI).) Technical Data 202 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Input/Output Ports (I/O) Freescale Semiconductor Input/Output Ports (I/O) Port A 12.3.2 Data Direction Register A Data direction register A determines whether each port A pin is an input or an output. Writing a logic 1 to a DDRA bit enables the output buffer for the corresponding port A pin; a logic 0 disables the output buffer. Address: $0004 Bit 7 6 5 4 3 2 1 Bit 0 DDRA7 DDRA6 DDRA5 DDRA4 DDRA3 DDRA2 DDRA1 DDRA0 0* 0 0 0 0 0 0 0 Read: Write: Reset: * DDRA7 bit is reset by POR or LVI reset only. Figure 12-3. Data Direction Register A (DDRA) DDRA[7:0] — Data Direction Register A Bits These read/write bits control port A data direction. Reset clears DDRA[7:0], configuring all port A pins as inputs. 1 = Corresponding port A pin configured as output 0 = Corresponding port A pin configured as input NOTE: Avoid glitches on port A pins by writing to the port A data register before changing data direction register A bits from 0 to 1. Figure 12-4 shows the port A I/O logic. READ DDRA ($0004) INTERNAL DATA BUS WRITE DDRA ($0004) RESET DDRAx WRITE PTA ($0000) PTAx PTAx READ PTA ($0000) Figure 12-4. Port A I/O Circuit MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Input/Output Ports (I/O) Technical Data 203 Input/Output Ports (I/O) When bit DDRAx is a logic 1, reading address $0000 reads the PTAx data latch. When bit DDRAx is a logic 0, reading address $0000 reads the voltage level on the pin. The data latch can always be written, regardless of the state of its data direction bit. Table 12-2 summarizes the operation of the port A pins. Table 12-2. Port A Pin Functions DDRA Bit PTA Bit I/O Pin Mode Accesses to DDRA Accesses to PTA Read/Write Read Write 0 X(1) Input, Hi-Z(2) DDRA[7:0] Pin PTA[7:0](3) 1 X Output DDRA[7:0] PTA[7:0] PTA[7:0] NOTES: 1. X = don’t care. 2. Hi-Z = high impedance. 3. Writing affects data register, but does not affect input. 12.4 Port B Port B is an 8-bit general-purpose bidirectional I/O port with software configurable pullups. 12.4.1 Port B Data Register The port B data register contains a data latch for each of the eight port B pins. NOTE: PTB7–PTB0 are not available in the 20-pin PDIP, 20-pin SOIC, and 28-pin SOIC packages. Address: $0001 Bit 7 6 5 4 3 2 1 Bit 0 PTB7 PTB6 PTB5 PTB4 PTB3 PTB2 PTB1 PTB0 Optional pullup Optional pullup Optional pullup Read: Write: Reset: Additional Optional Function: pullup Unaffected by reset Optional pullup Optional pullup Optional pullup Optional pullup Figure 12-5. Port B Data Register (PTB) Technical Data 204 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Input/Output Ports (I/O) Freescale Semiconductor Input/Output Ports (I/O) Port B PTB[7:0] — Port B Data Bits These read/write bits are software-programmable. Data direction of each port B pin is under the control of the corresponding bit in data direction register B. Reset has no effect on port B data. The port B pullup enable bit, PBP, in the port option control register (POCR) enables pullups on port B pins if the respective pin is configured as an input. (See 12.8 Port Options.) 12.4.2 Data Direction Register B Data direction register B determines whether each port B pin is an input or an output. Writing a logic 1 to a DDRB bit enables the output buffer for the corresponding port B pin; a logic 0 disables the output buffer. Address: $0005 Bit 7 6 5 4 3 2 1 Bit 0 DDRB7 DDRB6 DDRB5 DDRB4 DDRB3 DDRB2 DDRB1 DDRB0 0 0 0 0 0 0 0 0 Read: Write: Reset: Figure 12-6. Data Direction Register B (DDRB) DDRB[7:0] — Data Direction Register B Bits These read/write bits control port B data direction. Reset clears DDRB[7:0], configuring all port B pins as inputs. 1 = Corresponding port B pin configured as output 0 = Corresponding port B pin configured as input NOTE: Avoid glitches on port B pins by writing to the port B data register before changing data direction register B bits from 0 to 1. NOTE: For those devices packaged in a 20-pin PDIP, 20-pin SOIC, and 28-pin SOIC package, PTB7–PTB0 are not connected. DDRB7–DDRB0 should be set to a 1 to configure PTB7–PTB0 as outputs. Figure 12-7 shows the port B I/O logic. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Input/Output Ports (I/O) Technical Data 205 Input/Output Ports (I/O) READ DDRB ($0005) INTERNAL DATA BUS WRITE DDRB ($0005) DDRBx RESET WRITE PTB ($0001) PTBx PTBx READ PTB ($0001) Figure 12-7. Port B I/O Circuit When bit DDRBx is a logic 1, reading address $0001 reads the PTBx data latch. When bit DDRBx is a logic 0, reading address $0001 reads the voltage level on the pin. The data latch can always be written, regardless of the state of its data direction bit. Table 12-3 summarizes the operation of the port B pins. Table 12-3. Port B Pin Functions DDRB Bit PTB Bit I/O Pin Mode Accesses to DDRB Accesses to PTB Read/Write Read Write 0 X(1) Input, Hi-Z(2) DDRB[7:0] Pin PTB[7:0](3) 1 X Output DDRB[7:0] PTB[7:0] PTB[7:0] NOTES: 1. X = don’t care. 2. Hi-Z = high impedance. 3. Writing affects data register, but does not affect input. Technical Data 206 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Input/Output Ports (I/O) Freescale Semiconductor Input/Output Ports (I/O) Port C 12.5 Port C Port C is an 8-bit general-purpose bidirectional I/O port with software configurable pullups and current drive options. 12.5.1 Port C Data Register The port C data register contains a data latch for each of the eight port C pins. NOTE: PTC7–PTC1 are not available in the 20-pin PDIP, 20-pin SOIC, and 28-pin SOIC packages. Address: $0002 Bit 7 6 5 4 3 2 1 Bit 0 PTC7 PTC6 PTC5 PTC4 PTC3 PTC2 PTC1 PTC0 Optional pullup Optional pullup Optional pullup Read: Write: Reset: Additional Optional Function: pullup Unaffected by reset Optional pullup Optional pullup Optional pullup Optional pullup Figure 12-8. Port C Data Register (PTC) PTC[7:0] — Port C Data Bits These read/write bits are software-programmable. Data direction of each port C pin is under the control of the corresponding bit in data direction register C. Reset has no effect on port C data. The port C pullup enable bit, PCP, in the port option control register (POCR) enables pullups on port C pins if the respective pin is configured as an input. (See 12.8 Port Options.) MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Input/Output Ports (I/O) Technical Data 207 Input/Output Ports (I/O) 12.5.2 Data Direction Register C Data direction register C determines whether each port C pin is an input or an output. Writing a logic 1 to a DDRC bit enables the output buffer for the corresponding port C pin; a logic 0 disables the output buffer. Address: $0006 Bit 7 6 5 4 3 2 1 Bit 0 DDRC7 DDRC6 DDRC5 DDRC4 DDRC3 DDRC2 DDRC1 DDRC0 0 0 0 0 0 0 0 0 Read: Write: Reset: Figure 12-9. Data Direction Register C (DDRC) DDRC[7:0] — Data Direction Register C Bits These read/write bits control port C data direction. Reset clears DDRC[7:0], configuring all port C pins as inputs. 1 = Corresponding port C pin configured as output 0 = Corresponding port C pin configured as input NOTE: Avoid glitches on port C pins by writing to the port C data register before changing data direction register C bits from 0 to 1. NOTE: For those devices packaged in a 20-pin PDIP, 20-pin SOIC, and 28-pin SOIC package, PTC7–PTC1 are not connected. DDRC7–DDRC1 should be set to a 1 to configure PTC7–PTC1 as outputs. Figure 12-10 shows the port C I/O logic. Technical Data 208 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Input/Output Ports (I/O) Freescale Semiconductor Input/Output Ports (I/O) Port D READ DDRC ($0006) INTERNAL DATA BUS WRITE DDRC ($0006) DDRCx RESET WRITE PTC ($0002) PTCx PTCx READ PTC ($0002) Figure 12-10. Port C I/O Circuit When bit DDRCx is a logic 1, reading address $0002 reads the PTCx data latch. When bit DDRCx is a logic 0, reading address $0002 reads the voltage level on the pin. The data latch can always be written, regardless of the state of its data direction bit. Table 12-4 summarizes the operation of the port C pins. Table 12-4. Port C Pin Functions DDRC Bit PTC Bit I/O Pin Mode Accesses to DDRC Accesses to PTC Read/Write Read Write 0 X(1) Input, Hi-Z(2) DDRC[7:0] Pin PTC[7:0](3) 1 X Output DDRC[7:0] PTC[7:0] PTC[7:0] NOTES: 1. X = don’t care. 2. Hi-Z = high impedance. 3. Writing affects data register, but does not affect input. 12.6 Port D Port D is an 8-bit general-purpose bidirectional I/O port. In 20-pin package, PTD1 and PTD0 internal pads are bonded together to PTD0/1 pin. Port D pins are open-drain when configured as output, and can interface with 5V logic. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Input/Output Ports (I/O) Technical Data 209 Input/Output Ports (I/O) 12.6.1 Port D Data Register The port D data register contains a data latch for each of the eight port D pins. NOTE: PTD7–PTD2 are not available in the 20-pin PDIP and 20-pin SOIC packages. PTD7 is not available in the 28-pin SOIC package. Address: $0003 Bit 7 6 5 4 3 2 1 Bit 0 PTD7 PTD6 PTD5 PTD4 PTD3 PTD2 PTD1 PTD0 Read: Write: Reset: Unaffected by reset Additional Open-drain Open-drain Open-drain Open-drain Open-drain Open-drain Open-drain Open-drain Function: 10mA 10mA 10mA 10mA 25mA 25mA sink sink sink sink sink sink Figure 12-11. Port D Data Register (PTD) PTD[7:0] — Port D Data Bits These read/write bits are software programmable. Data direction of each port D pin is under control of the corresponding bit in data direction register D. Reset has no effect on port D data. The LED direct drive bit, PTDLDD, in the port option control register (POCR) controls the drive options for the PTD5–PTD2 pins. The infrared LED drive bit, PTDILDD, in the POCR controls the drive options for the PTD1–PTD0 pins. (See 12.8 Port Options.) NOTE: Technical Data 210 In 20-pin package, PTD1 and PTD0 are bonded together to PTD0/1 pin, forming a 50mA high current sink pin. When both PTD1 and PTD0 are configured as output, the values of PTD0 and PTD1 should be written the same. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Input/Output Ports (I/O) Freescale Semiconductor Input/Output Ports (I/O) Port D 12.6.2 Data Direction Register D Data direction register D determines whether each port D pin is an input or an output. Writing a logic 1 to a DDRD bit enables the output buffer for the corresponding port D pin; a logic 0 disables the output buffer. Address: $0007 Bit 7 6 5 4 3 2 1 Bit 0 DDRD7 DDRD6 DDRD5 DDRD4 DDRD3 DDRD2 DDRD1 DDRD0 0 0 0 0 0 0 0 0 Read: Write: Reset: Figure 12-12. Data Direction Register D (DDRD) DDRD[7:0] — Data Direction Register D Bits These read/write bits control port D data direction. Reset clears DDRD[7:0], configuring all port D pins as inputs. 1 = Corresponding port D pin configured as output 0 = Corresponding port D pin configured as input Port D pins are open-drain when configured as output. NOTE: Avoid glitches on port D pins by writing to the port D data register before changing data direction register D bits from 0 to 1. NOTE: For those devices packaged in a 20-pin PDIP and 20-pin SOIC package, PTD7–PTD2 are not connected. DDRD7–DDRD2 should be set to a 1 to configure PTD7–PTD2 as outputs. For those devices packaged in a 28-pin SOIC package, PTD7 is not connected. DDRD7 should be set to a 1 to configure PTD7 as output. Figure 12-13 shows the port D I/O circuit logic. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Input/Output Ports (I/O) Technical Data 211 Input/Output Ports (I/O) READ DDRD ($0007) INTERNAL DATA BUS WRITE DDRD ($0007) DDRDx RESET WRITE PTD ($0003) PTDx PTDx READ PTD ($0003) Figure 12-13. Port D I/O Circuit When bit DDRDx is a logic 1, reading address $0003 reads the PTDx data latch. When bit DDRDx is a logic 0, reading address $0003 reads the voltage level on the pin. The data latch can always be written, regardless of the state of its data direction bit. Table 12-5 summarizes the operation of the port D pins. Table 12-5. Port D Pin Functions DDRD Bit PTD Bit I/O Pin Mode Accesses to DDRD Accesses to PTD Read/Write Read Write 0 X(1) Input, Hi-Z(2) DDRD[7:0] Pin PTD[7:0](3) 1 X Output DDRD[7:0] PTD[7:0] PTD[7:0] NOTES: 1. X = don’t care. 2. Hi-Z = high impedance. 3. Writing affects data register, but does not affect input. 12.7 Port E Port E is a 5-bit special function port that shares three of its pins with the timer interface module (TIM) and two of its pins with the USB data pins D+ and D–. PTE4 and PTE3 are open drain when configured as output. Technical Data 212 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Input/Output Ports (I/O) Freescale Semiconductor Input/Output Ports (I/O) Port E 12.7.1 Port E Data Register The port E data register contains a data latch for each of the five port E pins. NOTE: PTE2 and PTE0 are not available in the 20-pin PDIP and 20-pin SOIC packages. Address: Read: $0008 Bit 7 6 5 0 0 0 4 3 2 1 Bit 0 PTE4 PTE3 PTE2 PTE1 PTE0 Write: Reset: Unaffected by reset Alternative D– D+ TCH1 TCH0 TCLK Additional Function: Optional pullup Optional pullup Optional pullup Optional pullup Optional pullup Additional Function: External interrupt Function: Open-drain Open-drain = Unimplemented Figure 12-14. Port E Data Register (PTE) PTE[4:0] — Port E Data Bits PTE[4:0] are read/write, software-programmable bits. Data direction of each port E pin is under the control of the corresponding bit in data direction register E. The PTE4 and PTE3 pullup enable bits, PTE4P and PTE3P, in the port option control register (POCR) enable 5kΩ pullups on PTE4 and PTE3 if the respective pin is configured as an input and the USB module is disabled. (See 12.8 Port Options.) The PTE[2:0] pullup enable bit, PTE20P, in the port option control register (POCR) enables pullups on PTE2–PTE0, regardless of the pin is configured as an input or an output. (See 12.8 Port Options.) MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Input/Output Ports (I/O) Technical Data 213 Input/Output Ports (I/O) PTE4 pin functions as an external interrupt when PTE4IE=1 in the IRQ option control register (IOCR) and USBEN=0 in the USB address register (USB disabled). (See 13.9 IRQ Option Control Register.) D– and D+ — USB Data Pins D– and D+ are the differential data lines used by the USB module. (See Section 9. Universal Serial Bus Module (USB).) The USB module enable bit, USBEN, in the USB address register (UADDR) controls the pin options for PTE4/D– and PTE3/D+. When the USB module is enabled, PTE4/D– and PTE3/D+ function as USB data pins D– and D+. When the USB module is disabled, PTE4/D– and PTE3/D+ function as 10mA open-drain pins for PS/2 clock and data use. The Pullup enable bit, PULLEN, in the USB control register 3 (UCR3) enables a 1.5kΩ pullup on D– pin when the USB module is enabled. (See 9.8.8 USB Control Register 3.) NOTE: PTE4/D– pin has two programmable pullup resistors. One is used for PTE4 when the USB module is disabled and another is used for D– when the USB module is enabled. TCH1–TCH0 — Timer Channel I/O Bits The PTE2/TCH1–PTE1/TCH0 pins are the TIM input capture/output compare pins. The edge/level select bits, ELSxB and ELSxA, determine whether the PTE2/TCH1–PTE1/TCH0 pins are timer channel I/O pins or general-purpose I/O pins. (See Section 11. Timer Interface Module (TIM).) TCLK — Timer Clock Input The PTE0/TCLK pin is the external clock input for the TIM. The prescaler select bits, PS[2:0], select PTE0/TCLK as the TIM clock input. When not selected as the TIM clock, PTE0/TCLK is available for general purpose I/O. (See Section 11. Timer Interface Module (TIM).) NOTE: Technical Data 214 Data direction register E (DDRE) does not affect the data direction of port E pins that are being used by the TIM. However, the DDRE bits always determine whether reading port E returns the states of the latches or the states of the pins. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Input/Output Ports (I/O) Freescale Semiconductor Input/Output Ports (I/O) Port E 12.7.2 Data Direction Register E Data direction register E determines whether each port E pin is an input or an output. Writing a logic 1 to a DDRE bit enables the output buffer for the corresponding port E pin; a logic 0 disables the output buffer. Address: Read: $0009 Bit 7 6 5 0 0 0 4 3 2 1 Bit 0 DDRE4 DDRE3 DDRE2 DDRE1 DDRE0 0 0 0 0 0 Write: Reset: 0 0 0 = Unimplemented Figure 12-15. Data Direction Register E (DDRE) DDRE[4:0] — Data Direction Register E Bits These read/write bits control port E data direction. Reset clears DDRE[4:0], configuring all port E pins as inputs. 1 = Corresponding port E pin configured as output 0 = Corresponding port E pin configured as input PTE4 and PTE3 pins are open-drain when configured as output. NOTE: Avoid glitches on port E pins by writing to the port E data register before changing data direction register E bits from 0 to 1. NOTE: For those devices packaged in a 20-pin PDIP and 20-pin SOIC package, PTE2 and PTE0 are not connected. DDRE2 and DDRE0 should be set to a 1 to configure PTE2 and PTE0 as outputs. Figure 12-16 shows the port E I/O circuit logic. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Input/Output Ports (I/O) Technical Data 215 Input/Output Ports (I/O) READ DDRE ($000C) INTERNAL DATA BUS WRITE DDRE ($000C) DDREx RESET WRITE PTE ($0008) PTEx PTEx READ PTE ($0008) Figure 12-16. Port E I/O Circuit When bit DDREx is a logic 1, reading address $0008 reads the PTEx data latch. When bit DDREx is a logic 0, reading address $0008 reads the voltage level on the pin. The data latch can always be written, regardless of the state of its data direction bit. Table 12-4 summarizes the operation of the port E pins. Table 12-6. Port E Pin Functions DDRE Bit PTE Bit I/O Pin Mode Accesses to DDRE Accesses to PTE Read/Write Read Write 0 X(1) Input, Hi-Z(2) DDRE[4:0] Pin PTE[4:0](3) 1 X Output DDRE[4:0] PTE[4:0] PTE[4:0] NOTES: 1. X = don’t care. 2. Hi-Z = high impedance. 3. Writing affects data register, but does not affect input. 12.8 Port Options All pins of port A, port B, port C, and port E have programmable pullup resistors. Port pins PTD5–PTD0 have LED drive capability. Port pins PTE4 and PTE3 have 10mA high current drive capability. Technical Data 216 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Input/Output Ports (I/O) Freescale Semiconductor Input/Output Ports (I/O) Port Options 12.8.1 Port Option Control Register The port option control register controls the pullup options for port A, B, C, and E pins. It also controls the drive configuration on port D. Address: $001D Bit 7 6 5 4 3 2 1 Bit 0 PTE4P PTE3P PCP PBP PAP 0 0 0 0 0 Read: PTE20P PTDLDD PTDILDD Write: Reset: 0 0 0 Figure 12-17. Port Option Control Register (POCR) PTE20P — Port PTE2–PTE0 Pullup Enable This read/write bit controls the pullup option for the PTE2–PTE0 pins, regardless whether the pins are input or output. 1 = Configure PTE2–PTE0 to have internal pullups to VREG 0 = Disconnect PTE2–PTE0 internal pullups PTDLDD — LED Direct Drive Control This read/write bit controls the output current capability of PTD5–PTD2 pins. When set, each port pin has 10mA current sink limit. An LED can be connected directly between the port pin and VDD without the need of a series resistor. 1 = PTD5–PTD2 configured for direct LED drive capability; when a pin is set as an output, the pin is an open-drain pin with 10mA current sink limit 0 = PTD5–PTD2 configured as standard open-drain I/O port pin PTDILDD — Infrared LED Drive Control This read/write bit controls the output current capability of PTD1 and PTD0 pins. When set, each port pin has 25mA current sink capability. An infrared LED can be connected directly between the port pin and VDD. 1 = PTD1 and PTD0 configured for infrared LED drive capability; when a pin is set as an output, the pin is an open-drain pin with 25mA current sink capability 0 = PTD1 and PTD0 configured as standard open-drain I/O port pins MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Input/Output Ports (I/O) Technical Data 217 Input/Output Ports (I/O) PTE4P — Pin PTE4 Pullup Enable This read/write bit controls the pullup option for the PTE4 pin when the pin is configured as an input and the USB module is disabled. 1 = Configure PTE4 to have internal pullup to VDD 0 = Disconnect PTE4 internal pullup NOTE: When the USB module is enabled, the pullup controlled by PTE4P is disconnected; PTE4/D– pin functions as D– which has a 1.5kΩ programmable pullup resistor. (See 9.8.8 USB Control Register 3.) PTE3P — Pin PTE3 Pullup Enable This read/write bit controls the pullup option for the PTE3 pin when the pin is configured as an input and the USB module is disabled. 1 = Configure PTE3 to have internal pullup to VDD 0 = Disconnect PTE3 internal pullup PCP — Port C Pullup Enable This read/write bit controls the pullup option for the PTC7–PTC0 pins. When set, a pullup device is connected when a pin is configured as an input. 1 = Configure port C to have internal pullups to VREG 0 = Disconnect port C internal pullups PBP — Port B Pullup Enable This read/write bit controls the pullup option for the PTB7–PTB0 pins. When set, a pullup device is connected when a pin is configured as an input. 1 = Configure port B to have internal pullups to VREG 0 = Disconnect port B internal pullups PAP — Port A Pullup Enable This read/write bit controls the pullup option for the PTA7–PTA0 pins. When set, a pullup device is connected when a pin is configured as an input. 1 = Configure port A to have internal pullups to VREG 0 = Disconnect port A internal pullups Technical Data 218 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Input/Output Ports (I/O) Freescale Semiconductor Technical Data — MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 Section 13. External Interrupt (IRQ) 13.1 Contents 13.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219 13.3 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219 13.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .220 13.5 IRQ Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222 13.6 PTE4/D– Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223 13.7 IRQ Module During Break Interrupts . . . . . . . . . . . . . . . . . . . 223 13.8 IRQ Status and Control Register . . . . . . . . . . . . . . . . . . . . . . 224 13.9 IRQ Option Control Register. . . . . . . . . . . . . . . . . . . . . . . . . . 225 13.2 Introduction The IRQ module provides two external interrupt inputs: one dedicated IRQ pin and one shared port pin, PTE4/D–. 13.3 Features Features of the IRQ module include: • Two external interrupt pins, IRQ (5V) and PTE4/D– (5V) • IRQ interrupt control bits • Hysteresis buffer • Programmable edge-only or edge and level interrupt sensitivity • Automatic interrupt acknowledge • Low leakage IRQ pin for external RC wake up input • Selectable internal pullup resistor MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor External Interrupt (IRQ) Technical Data 219 External Interrupt (IRQ) 13.4 Functional Description A logic 0 applied to the external interrupt pin can latch a CPU interrupt request. Figure 13-1 shows the structure of the IRQ module. Interrupt signals on the IRQ pin are latched into the IRQ latch. An interrupt latch remains set until one of the following actions occurs: • Vector fetch — A vector fetch automatically generates an interrupt acknowledge signal that clears the IRQ latch. • Software clear — Software can clear the interrupt latch by writing to the acknowledge bit in the interrupt status and control register (ISCR). Writing a logic 1 to the ACK bit clears the IRQ latch. • Reset — A reset automatically clears the interrupt latch. The external interrupt pin is falling-edge-triggered and is softwareconfigurable to be either falling-edge or low-level-triggered. The MODE bit in the ISCR controls the triggering sensitivity of the IRQ pin. When the interrupt pin is edge-triggered only, the CPU interrupt request remains set until a vector fetch, software clear, or reset occurs. When the interrupt pin is both falling-edge and low-level-triggered, the CPU interrupt request remains set until both of the following occur: • Vector fetch or software clear • Return of the interrupt pin to logic one The vector fetch or software clear may occur before or after the interrupt pin returns to logic 1. As long as the pin is low, the interrupt request remains pending. A reset will clear the latch and the MODE control bit, thereby clearing the interrupt even if the pin stays low. When set, the IMASK bit in the ISCR mask all external interrupt requests. A latched interrupt request is not presented to the interrupt priority logic unless the IMASK bit is clear. NOTE: Technical Data 220 The interrupt mask (I) in the condition code register (CCR) masks all interrupt requests, including external interrupt requests. (See 8.6 Exception Control.) MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 External Interrupt (IRQ) Freescale Semiconductor External Interrupt (IRQ) Functional Description INTERNAL ADDRESS BUS ACK RESET VECTOR FETCH DECODER HIGH VOLTAGE DETECT TO MODE SELECT LOGIC TO CPU FOR BIL/BIH INSTRUCTIONS VDD IRQPD "1" IRQF INTERNAL PULLUP D DEVICE IRQ CLR Q SYNCHRONIZER CK IRQ INTERRUPT REQUEST IRQ FF IMASK MODE TO PTE4 PULLUP ENABLE CIRCUITRY "1" READ IOCR D PTE4 CLR Q PTE4IF CK PTE4IE Figure 13-1. IRQ Module Block Diagram Addr. $001C $001E Register Name Bit 7 6 5 4 3 2 IRQ Option Control Register Read: (IOCR) Write: 0 0 0 0 0 PTE4IF Reset: 0 0 0 0 0 0 IRQ Status and Control Register Read: (ISCR) Write: 0 0 0 0 IRQF 0 Reset: 0 1 Bit 0 PTE4IE IRQPD 0 0 IMASK MODE 0 0 ACK 0 0 0 0 0 = Unimplemented Figure 13-2. IRQ I/O Register Summary MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor External Interrupt (IRQ) Technical Data 221 External Interrupt (IRQ) 13.5 IRQ Pin The IRQ pin has a low leakage for input voltages ranging from 0V to VDD; suitable for applications using RC discharge circuitry to wake up the MCU. A logic 0 on the IRQ pin can latch an interrupt request into the IRQ latch. A vector fetch, software clear, or reset clears the IRQ latch. If the MODE bit is set, the IRQ pin is both falling-edge-sensitive and lowlevel-sensitive. With MODE set, both of the following actions must occur to clear IRQ: • Vector fetch or software clear — A vector fetch generates an interrupt acknowledge signal to clear the latch. Software may generate the interrupt acknowledge signal by writing a logic 1 to the ACK bit in the interrupt status and control register (ISCR). The ACK bit is useful in applications that poll the IRQ pin and require software to clear the IRQ latch. Writing to the ACK bit prior to leaving an interrupt service routine can also prevent spurious interrupts due to noise. Setting ACK does not affect subsequent transitions on the IRQ pin. A falling edge that occurs after writing to the ACK bit latches another interrupt request. If the IRQ mask bit, IMASK, is clear, the CPU loads the program counter with the vector address at locations $FFF8 and $FFF9. • Return of the IRQ pin to logic one — As long as the IRQ pin is at logic zero, IRQ remains active. The vector fetch or software clear and the return of the IRQ pin to logic one may occur in any order. The interrupt request remains pending as long as the IRQ pin is at logic zero. A reset will clear the latch and the MODE control bit, thereby clearing the interrupt even if the pin stays low. If the MODE bit is clear, the IRQ pin is falling-edge-sensitive only. With MODE clear, a vector fetch or software clear immediately clears the IRQ latch. The IRQF bit in the ISCR register can be used to check for pending interrupts. The IRQF bit is not affected by the IMASK bit, which makes it useful in applications where polling is preferred. Technical Data 222 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 External Interrupt (IRQ) Freescale Semiconductor External Interrupt (IRQ) PTE4/D– Pin Use the BIH or BIL instruction to read the logic level on the IRQ pin. NOTE: When using the level-sensitive interrupt trigger, avoid false interrupts by masking interrupt requests in the interrupt routine. NOTE: An internal pullup resistor to VDD is connected to IRQ pin; this can be disabled by setting the IRQPD bit in the IRQ option control register ($001C). 13.6 PTE4/D– Pin The PTE4 pin is configured as an interrupt input to trigger the IRQ interrupt when the following conditions are satisfied: • The USB module is disabled (USBEN = 0) • PTE4 pin configured for external interrupt input (PTE4IE = 1) Setting PTE4IE configures the PTE4 pin to an input pin with an internal pullup device. The PTE4 interrupt is "ORed" with the IRQ input to trigger the IRQ interrupt (see Figure 13-1 . IRQ Module Block Diagram). Therefore, the IRQ status and control register affects both the IRQ pin and the PTE pin. An interrupt on PTE4 also sets the PTE4 interrupt flag, PTE4IF, in the IRQ option control register (IOCR). 13.7 IRQ Module During Break Interrupts The system integration module (SIM) controls whether the IRQ latch can be cleared during the break state. The BCFE bit in the break flag control register (BFCR) enables software to clear the latches during the break state. (See Section 8. System Integration Module (SIM).) To allow software to clear the IRQ latch during a break interrupt, write a logic 1 to the BCFE bit. If a latch is cleared during the break state, it remains cleared when the MCU exits the break state. To protect the latches during the break state, write a logic 0 to the BCFE bit. With BCFE at logic 0 (its default state), writing to the ACK bit in the IRQ status and control register during the break state has no effect on the IRQ latch. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor External Interrupt (IRQ) Technical Data 223 External Interrupt (IRQ) 13.8 IRQ Status and Control Register The IRQ status and control register (ISCR) controls and monitors operation of the IRQ module. The ISCR has the following functions: • Shows the state of the IRQ flag • Clears the IRQ latch • Masks IRQ interrupt request • Controls triggering sensitivity of the IRQ pin Address: Read: $001E Bit 7 6 5 4 3 2 0 0 0 0 IRQF 0 Write: Reset: 1 Bit 0 IMASK MODE 0 0 ACK 0 0 0 0 0 0 = Unimplemented Figure 13-3. IRQ Status and Control Register (ISCR) IRQF — IRQ Flag This read-only status bit is high when the IRQ interrupt is pending. 1 = IRQ interrupt pending 0 = IRQ interrupt not pending ACK — IRQ Interrupt Request Acknowledge Bit Writing a logic 1 to this write-only bit clears the IRQ latch. ACK always reads as logic 0. Reset clears ACK. IMASK — IRQ Interrupt Mask Bit Writing a logic 1 to this read/write bit disables IRQ interrupt requests. Reset clears IMASK. 1 = IRQ interrupt requests disabled 0 = IRQ interrupt requests enabled MODE — IRQ Edge/Level Select Bit This read/write bit controls the triggering sensitivity of the IRQ pin. Reset clears MODE. 1 = IRQ interrupt requests on falling edges and low levels Technical Data 224 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 External Interrupt (IRQ) Freescale Semiconductor External Interrupt (IRQ) IRQ Option Control Register 0 = IRQ interrupt requests on falling edges only 13.9 IRQ Option Control Register The IRQ option control register controls and monitors the external interrupt function available on the PTE4 pin. It also disables/enables the pullup resistor on the IRQ pin. • Controls pullup option on IRQ pin • Enables PTE4 pin for external interrupts to IRQ • Shows the state of the PTE4 interrupt flag Address: Read: $001C Bit 7 6 5 4 3 2 0 0 0 0 0 PTE4IF 1 Bit 0 PTE4IE IRQPD 0 0 Write: Reset: 0 0 0 0 0 0 = Unimplemented Figure 13-4. IRQ Option Control Register (IOCR) PTE4IF — PTE4 Interrupt Flag This read-only status bit is high when a falling edge on PTE4 pin is detected. PTE4IF bit clears when the IOCR is read. 1 = Falling edge on PTE4 is detected and PTE4IE is set 0 = Falling edge on PTE4 is not detected or PTE4IE is clear PTE4IE — PTE4 Interrupt Enable This read/write bit enables or disables the interrupt function on the PTE4 pin to trigger the IRQ interrupt. Setting the PTE4IE bit and clearing the USBEN bit in the USB address register configure the PTE4 pin for interrupt function to the IRQ interrupt. Setting PTE4IE also enables the internal pullup on PTE4 pin. 1 = PTE4 interrupt enabled; triggers IRQ interrupt 0 = PTE4 interrupt disabled IRQPD — IRQ Pullup Disable MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor External Interrupt (IRQ) Technical Data 225 External Interrupt (IRQ) This read/write bit controls the pullup option for the IRQ pin. 1 = Internal pullup is disconnected 0 = Internal pull-up is connected between IRQ pin and VDD Technical Data 226 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 External Interrupt (IRQ) Freescale Semiconductor Technical Data — MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 Section 14. Keyboard Interrupt Module (KBI) 14.1 Contents 14.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227 14.3 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228 14.4 Pin Name Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228 14.5 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .230 14.6 Keyboard Initialization. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231 14.7 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232 14.7.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .232 14.7.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .232 14.8 Keyboard Module During Break Interrupts . . . . . . . . . . . . . . . 233 14.9 I/O Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233 14.9.1 Keyboard Status and Control Register. . . . . . . . . . . . . . . . 233 14.9.2 Keyboard Interrupt Enable Register . . . . . . . . . . . . . . . . . . 235 14.2 Introduction The keyboard interrupt module (KBI) provides eight independently maskable external interrupts which are accessible via PTA0–PTA7 pins. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Keyboard Interrupt Module (KBI) Technical Data 227 Keyboard Interrupt Module (KBI) 14.3 Features Features of the keyboard interrupt module include: • Eight keyboard interrupt pins with separate keyboard interrupt enable bits and one keyboard interrupt mask • Hysteresis buffers • Programmable edge-only or edge- and level-interrupt sensitivity • Exit from low-power modes 14.4 Pin Name Conventions The KBI share eight I/O pins with eight port A I/O pins. The full name of the I/O pins are listed in Table 14-1. The generic pin name appear in the text that follows. Table 14-1. KBI Pin Name Conventions Technical Data 228 Full KBI Pin Names: KBI Generic Pin Names: PTA7/KBA7 KBA7 PTA7/KBA6 KBA6 PTA7/KBA5 KBA5 PTA7/KBA4 KBA4 PTA7/KBA3 KBA3 PTA7/KBA2 KBA2 PTA7/KBA1 KBA1 PTA7/KBA0 KBA0 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Keyboard Interrupt Module (KBI) Freescale Semiconductor Keyboard Interrupt Module (KBI) Pin Name Conventions INTERNAL BUS KBA0 ACKK VREG VECTOR FETCH DECODER KEYF RESET . KBIE0 D CLR Q SYNCHRONIZER . Keyboard Interrupt Request CK TO PULLUP ENABLE . KEYBOARD INTERRUPT FF KBA7 IMASKK MODEK KBIE7 TO PULLUP ENABLE Figure 14-1. Keyboard Module Block Diagram Table 14-2. I/O Register Summary Addr. Register Name Bit 7 6 5 4 3 2 $0016 Keyboard Status and Control Read: Register (KBSCR) Write: 0 0 0 0 KEYF 0 Reset: 0 0 0 0 0 KBIE7 KBIE6 KBIE5 KBIE4 0 0 0 0 $0017 Keyboard Interrupt Enable Read: Register (KBIER) Write: Reset: 1 Bit 0 IMASKK MODEK 0 0 0 KBIE3 KBIE2 KBIE1 KBIE0 0 0 0 0 ACKK = Unimplemented MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Keyboard Interrupt Module (KBI) Technical Data 229 Keyboard Interrupt Module (KBI) 14.5 Functional Description Writing to the KBIE7–KBIE0 bits in the keyboard interrupt enable register independently enables or disables each port A pin as a keyboard interrupt pin. Enabling a keyboard interrupt pin also enables its internal pullup device. A logic 0 applied to an enabled keyboard interrupt pin latches a keyboard interrupt request. A keyboard interrupt is latched when one or more keyboard pins goes low after all were high. The MODEK bit in the keyboard status and control register controls the triggering mode of the keyboard interrupt. NOTE: • If the keyboard interrupt is edge-sensitive only, a falling edge on a keyboard pin does not latch an interrupt request if another keyboard pin is already low. • If the keyboard interrupt is falling edge- and low level-sensitive, an interrupt request is present as long as any keyboard pin is low. To prevent losing an interrupt request on one pin because another pin is still low, software can disable the latter pin while it is low. If the MODEK bit is set, the keyboard interrupt pins are both falling edgeand low level-sensitive, and both of the following actions must occur to clear a keyboard interrupt request: • Technical Data 230 Vector fetch or software clear — A vector fetch generates an interrupt acknowledge signal to clear the interrupt request. Software may generate the interrupt acknowledge signal by writing a logic 1 to the ACKK bit in the keyboard status and control register (KBSCR). The ACKK bit is useful in applications that poll the keyboard interrupt pins and require software to clear the keyboard interrupt request. Writing to the ACKK bit prior to leaving an interrupt service routine also can prevent spurious interrupts due to noise. Setting ACKK does not affect subsequent transitions on the keyboard interrupt pins. A falling edge that occurs after writing to the ACKK bit latches another interrupt request. If the keyboard interrupt mask bit, IMASKK, is clear, the CPU loads the program counter with the vector address at locations $FFF0 and $FFF1. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Keyboard Interrupt Module (KBI) Freescale Semiconductor Keyboard Interrupt Module (KBI) Keyboard Initialization • Return of all enabled keyboard interrupt pins to logic 1 — As long as any enabled keyboard interrupt pin is at logic 0, the keyboard interrupt remains set. The vector fetch or software clear and the return of all enabled keyboard interrupt pins to logic 1 may occur in any order. If the MODEK bit is clear, the keyboard interrupt pin is falling-edgesensitive only. With MODEK clear, a vector fetch or software clear immediately clears the keyboard interrupt request. Reset clears the keyboard interrupt request and the MODEK bit, clearing the interrupt request even if a keyboard interrupt pin stays at logic 0. The keyboard flag bit (KEYF) in the keyboard status and control register can be used to see if a pending interrupt exists. The KEYF bit is not affected by the keyboard interrupt mask bit (IMASKK) which makes it useful in applications where polling is preferred. To determine the logic level on a keyboard interrupt pin, use the data direction register to configure the pin as an input and read the data register. NOTE: Setting a keyboard interrupt enable bit (KBIEx) forces the corresponding keyboard interrupt pin to be an input, overriding the data direction register. However, the data direction register bit must be a logic 0 for software to read the pin. 14.6 Keyboard Initialization When a keyboard interrupt pin is enabled, it takes time for the pullup device to reach a logic 1. Therefore, a false interrupt can occur as soon as the pin is enabled. To prevent a false interrupt on keyboard initialization: 1. Mask keyboard interrupts by setting the IMASKK bit in the keyboard status and control register. 2. Enable the KBI pins by setting the appropriate KBIEx bits in the keyboard interrupt enable register. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Keyboard Interrupt Module (KBI) Technical Data 231 Keyboard Interrupt Module (KBI) 3. Write to the ACKK bit in the keyboard status and control register to clear any false interrupts. 4. Clear the IMASKK bit. An interrupt signal on an edge-triggered pin can be acknowledged immediately after enabling the pin. An interrupt signal on an edge- and level-triggered interrupt pin must be acknowledged after a delay that depends on the external load. Another way to avoid a false interrupt: 1. Configure the keyboard pins as outputs by setting the appropriate DDRA bits in data direction register A. 2. Write logic 1s to the appropriate port A data register bits. 3. Enable the KBI pins by setting the appropriate KBIEx bits in the keyboard interrupt enable register. 14.7 Low-Power Modes The WAIT and STOP instructions put the MCU in low-power consumption standby modes. 14.7.1 Wait Mode The keyboard module remains active in wait mode. Clearing the IMASKK bit in the keyboard status and control register enables keyboard interrupt requests to bring the MCU out of wait mode. 14.7.2 Stop Mode The keyboard module remains active in stop mode. Clearing the IMASKK bit in the keyboard status and control register enables keyboard interrupt requests to bring the MCU out of stop mode. Technical Data 232 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Keyboard Interrupt Module (KBI) Freescale Semiconductor Keyboard Interrupt Module (KBI) Keyboard Module During Break Interrupts 14.8 Keyboard Module During Break Interrupts The system integration module (SIM) controls whether the keyboard interrupt latch can be cleared during the break state. The BCFE bit in the break flag control register (BFCR) enables software to clear status bits during the break state. To allow software to clear the keyboard interrupt latch during a break interrupt, write a logic 1 to the BCFE bit. If a latch is cleared during the break state, it remains cleared when the MCU exits the break state. To protect the latch during the break state, write a logic 0 to the BCFE bit. With BCFE at logic 0 (its default state), writing to the keyboard acknowledge bit (ACKK) in the keyboard status and control register during the break state has no effect. (See 14.9.1 Keyboard Status and Control Register.) 14.9 I/O Registers These registers control and monitor operation of the keyboard module: • Keyboard status and control register (KBSCR) • Keyboard interrupt enable register (KBIER) 14.9.1 Keyboard Status and Control Register The keyboard status and control register: • Flags keyboard interrupt requests • Acknowledges keyboard interrupt requests • Masks keyboard interrupt requests • Controls keyboard interrupt triggering sensitivity MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Keyboard Interrupt Module (KBI) Technical Data 233 Keyboard Interrupt Module (KBI) Address: $0016 Read: Bit 7 6 5 4 3 2 0 0 0 0 KEYF 0 Write: Reset: 1 Bit 0 IMASKK MODEK 0 0 ACKK 0 0 0 0 0 0 = Unimplemented Figure 14-2. Keyboard Status and Control Register (KBSCR) Bits 7–4 — Not used These read-only bits always read as logic 0s. KEYF — Keyboard Flag Bit This read-only bit is set when a keyboard interrupt is pending. Reset clears the KEYF bit. 1 = Keyboard interrupt pending 0 = No keyboard interrupt pending ACKK — Keyboard Acknowledge Bit Writing a logic 1 to this write-only bit clears the keyboard interrupt request. ACKK always reads as logic 0. Reset clears ACKK. IMASKK — Keyboard Interrupt Mask Bit Writing a logic 1 to this read/write bit prevents the output of the keyboard interrupt mask from generating interrupt requests. Reset clears the IMASKK bit. 1 = Keyboard interrupt requests masked 0 = Keyboard interrupt requests not masked MODEK — Keyboard Triggering Sensitivity Bit This read/write bit controls the triggering sensitivity of the keyboard interrupt pins. Reset clears MODEK. 1 = Keyboard interrupt requests on falling edges and low levels 0 = Keyboard interrupt requests on falling edges only Technical Data 234 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Keyboard Interrupt Module (KBI) Freescale Semiconductor Keyboard Interrupt Module (KBI) I/O Registers 14.9.2 Keyboard Interrupt Enable Register The keyboard interrupt enable register enables or disables each port A pin to operate as a keyboard interrupt pin. Address: $0017 Bit 7 6 5 4 3 2 1 Bit 0 KBIE7 KBIE6 KBIE5 KBIE4 KBIE3 KBIE2 KBIE1 KBIE0 0 0 0 0 0 0 0 0 Read: Write: Reset: Figure 14-3. Keyboard Interrupt Enable Register (KBIER) KBIE7–KBIE0 — Keyboard Interrupt Enable Bits Each of these read/write bits enables the corresponding keyboard interrupt pin to latch interrupt requests. Reset clears the keyboard interrupt enable register. 1 = PTAx pin enabled as keyboard interrupt pin 0 = PTAx pin not enabled as keyboard interrupt pin MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Keyboard Interrupt Module (KBI) Technical Data 235 Keyboard Interrupt Module (KBI) Technical Data 236 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Keyboard Interrupt Module (KBI) Freescale Semiconductor Technical Data — MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 Section 15. Computer Operating Properly (COP) 15.1 Contents 15.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237 15.3 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .238 15.4 I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239 15.4.1 OSCXCLK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .239 15.4.2 STOP Instruction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239 15.4.3 COPCTL Write . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .239 15.4.4 Power-On Reset. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240 15.4.5 Internal Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240 15.4.6 Reset Vector Fetch. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240 15.4.7 COPD (COP Disable). . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240 15.4.8 COPRS (COP Rate Select) . . . . . . . . . . . . . . . . . . . . . . . . 240 15.5 COP Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241 15.6 Interrupts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .241 15.7 Monitor Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .241 15.8 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242 15.8.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .242 15.8.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .242 15.9 COP Module During Break Mode . . . . . . . . . . . . . . . . . . . . . . 242 15.2 Introduction The computer operating properly (COP) module contains a free-running counter that generates a reset if allowed to overflow. The COP module helps software recover from runaway code. Prevent a COP reset by clearing the COP counter periodically. The COP module can be disabled through the COPD bit in the CONFIG register. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Computer Operating Properly (COP) Technical Data 237 Computer Operating Properly (COP) 15.3 Functional Description Figure 15-1 shows the structure of the COP module. SIM OSCXCLK SIM RESET CIRCUIT RESET VECTOR FETCH RESET STATUS REGISTER COP TIMEOUT CLEAR ALL STAGES INTERNAL RESET SOURCES(1) CLEAR STAGES 5–12 12-BIT SIM COUNTER COPCTL WRITE COP CLOCK COP MODULE 6-BIT COP COUNTER COPEN (FROM SIM) COPD (FROM CONFIG) RESET COPCTL WRITE CLEAR COP COUNTER COP RATE SEL (COPRS FROM CONFIG) NOTE: 1. See SIM section for more details. Figure 15-1. COP Block Diagram The COP counter is a free-running 6-bit counter preceded by a 12-bit system integration module (SIM) counter. If not cleared by software, the COP counter overflows and generates an asynchronous reset after 218 – 24 or 213 – 24 OSCXCLK cycles, depending on the state of the COP rate select bit, COPRS in the configuration register. With a 218 – 24 OSCXCLK cycle overflow option (COPRS = 0), a 12MHz OSCXCLK clock (6MHz crystal) gives a COP timeout period of 21.84 ms. Writing any value to location $FFFF before an overflow occurs prevents a COP reset by clearing the COP counter and stages 12 through 5 of the SIM counter. Technical Data 238 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Computer Operating Properly (COP) Freescale Semiconductor Computer Operating Properly (COP) I/O Signals NOTE: Service the COP immediately after reset and before entering or after exiting stop mode to guarantee the maximum time before the first COP counter overflow. A COP reset pulls the RST pin low for 32 OSCXCLK cycles and sets the COP bit in the reset status register (RSR). In monitor mode, the COP is disabled if the RST pin or the IRQ is held at VDD + VHI. During the break state, VDD + VHI on the RST pin disables the COP. NOTE: Place COP clearing instructions in the main program and not in an interrupt subroutine. Such an interrupt subroutine could keep the COP from generating a reset even while the main program is not working properly. 15.4 I/O Signals The following paragraphs describe the signals shown in Figure 15-1. 15.4.1 OSCXCLK OSCXCLK is the clock doubler output signal. OSCXCLK frequency is double of the crystal frequency. 15.4.2 STOP Instruction The STOP instruction clears the COP prescaler. 15.4.3 COPCTL Write Writing any value to the COP control register (COPCTL) (see 15.5 COP Control Register) clears the COP counter and clears bits 12 through 5 of the SIM counter. Reading the COP control register returns the low byte of the reset vector. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Computer Operating Properly (COP) Technical Data 239 Computer Operating Properly (COP) 15.4.4 Power-On Reset The power-on reset (POR) circuit in the SIM clears the COP prescaler 4096 OSCXCLK cycles after power-up. 15.4.5 Internal Reset An internal reset clears the SIM counter and the COP counter. 15.4.6 Reset Vector Fetch A reset vector fetch occurs when the vector address appears on the data bus. A reset vector fetch clears the COP prescaler. 15.4.7 COPD (COP Disable) The COPD signal reflects the state of the COP disable bit (COPD) in the configuration register (CONFIG). 15.4.8 COPRS (COP Rate Select) The COPRS signal reflects the state of the COP rate select bit (COPRS) in the configuration register (CONFIG). Address: Read: $001F Bit 7 6 0 0 5 4 3 2 1 Bit 0 URSTD LVID SSREC COPRS STOP COPD 0 0 0 0 0 0 Write: Reset: 0 0 = Unimplemented Figure 15-2. Configuration Register (CONFIG) Technical Data 240 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Computer Operating Properly (COP) Freescale Semiconductor Computer Operating Properly (COP) COP Control Register COPRS — COP Rate Select Bit COPRS selects the COP timeout period. Reset clears COPRS. 1 = COP timeout period is (213 – 24) × OSCXOUT cycles 0 = COP timeout period is (218 – 24) × OSCXOUT cycles COPD — COP Disable Bit COPD disables the COP module. 1 = COP module disabled 0 = COP module enabled 15.5 COP Control Register The COP control register is located at address $FFFF and overlaps the reset vector. Writing any value to $FFFF clears the COP counter and starts a new timeout period. Reading location $FFFF returns the low byte of the reset vector. Address: $FFFF Bit 7 6 5 4 3 Read: Low byte of reset vector Write: Clear COP counter Reset: Unaffected by reset 2 1 Bit 0 Figure 15-3. COP Control Register (COPCTL) 15.6 Interrupts The COP does not generate CPU interrupt requests. 15.7 Monitor Mode The COP is disabled in monitor mode when VDD + VHI is present on the IRQ pin or on the RST pin. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Computer Operating Properly (COP) Technical Data 241 Computer Operating Properly (COP) 15.8 Low-Power Modes The WAIT and STOP instructions put the MCU in low-power consumption standby modes. 15.8.1 Wait Mode The COP remains active during wait mode. To prevent a COP reset during wait mode, periodically clear the COP counter in a CPU interrupt routine. 15.8.2 Stop Mode Stop mode turns off the OSCXCLK input to the COP and clears the COP prescaler. Service the COP immediately before entering or after exiting stop mode to ensure a full COP timeout period after entering or exiting stop mode. The STOP bit in the configuration register (CONFIG) enables the STOP instruction. To prevent inadvertently turning off the COP with a STOP instruction, disable the STOP instruction by clearing the STOP bit. 15.9 COP Module During Break Mode The COP is disabled during a break interrupt when VDD + VHI is present on the RST pin. Technical Data 242 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Computer Operating Properly (COP) Freescale Semiconductor Technical Data — MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 Section 16. Low Voltage Inhibit (LVI) 16.1 Contents 16.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243 16.3 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .243 16.4 LVI Control Register (CONFIG) . . . . . . . . . . . . . . . . . . . . . . .244 16.5 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244 16.5.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .244 16.5.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .244 16.2 Introduction This section describes the low-voltage inhibit module (LVI), which monitors the voltage on the VDD pin and generates a reset when the VDD voltage falls to the LVI trip (VLVR) voltage. 16.3 Functional Description Figure 16-1 shows the structure of the LVI module. The LVI is enabled after a reset. The LVI module contains a bandgap reference circuit and comparator. Setting LVI disable bit (LVID) disables the LVI to monitor VDD voltage. The LVI module generates one output signal: LVI Reset — an reset signal will be generated to reset the CPU when VDD drops to below the set trip point. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Low Voltage Inhibit (LVI) Technical Data 243 Low Voltage Inhibit (LVI) VDD LVID LOW VDD VDD > VLVR = 0 DETECTOR VDD < VLVR = 1 LVI RESET Figure 16-1. LVI Module Block Diagram 16.4 LVI Control Register (CONFIG) Address: Read: $001F Bit 7 6 0 0 5 4 3 2 1 Bit 0 URSTD LVID SSREC COPRS STOP COPD 0 0 0 0 0 0 Write: Reset: 0 0 One-time writable register after each reset. URSTD and LVID bits are reset by POR or LVI reset only. = Unimplemented Figure 16-2. Configuration Register (CONFIG) LVID —þLow Voltage Inhibit Disable Bit 1 = Low voltage inhibit disabled 0 = Low voltage inhibit enabled 16.5 Low-Power Modes The STOP and WAIT instructions put the MCU in low-power consumption standby modes. 16.5.1 Wait Mode The LVI module, when enabled, will continue to operate in WAIT Mode. 16.5.2 Stop Mode The LVI module, when enabled, will continue to operate in STOP Mode. Technical Data 244 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Low Voltage Inhibit (LVI) Freescale Semiconductor Technical Data — MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 Section 17. Break Module (BREAK) 17.1 Contents 17.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245 17.3 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 246 17.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .246 17.4.1 Flag Protection During Break Interrupts . . . . . . . . . . . . . . . 248 17.4.2 CPU During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . .248 17.4.3 TIM During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . 248 17.4.4 COP During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . 248 17.5 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248 17.5.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .248 17.5.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .249 17.6 Break Module Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249 17.6.1 Break Status and Control Register. . . . . . . . . . . . . . . . . . . 249 17.6.2 Break Address Registers . . . . . . . . . . . . . . . . . . . . . . . . . . 250 17.6.3 Break Status Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250 17.6.4 Break Flag Control Register (BFCR) . . . . . . . . . . . . . . . . . 252 17.2 Introduction This section describes the break module. The break module can generate a break interrupt that stops normal program flow at a defined address to enter a background program. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Break Module (BREAK) Technical Data 245 Break Module (BREAK) 17.3 Features Features of the break module include the following: • Accessible i/o registers during the break interrupt • CPU-generated break interrupts • Software-generated break interrupts • COP disabling during break interrupts 17.4 Functional Description When the internal address bus matches the value written in the break address registers, the break module issues a breakpoint signal (BKPT) to the SIM. The SIM then causes the CPU to load the instruction register with a software interrupt instruction (SWI) after completion of the current CPU instruction. The program counter vectors to $FFFC and $FFFD ($FEFC and $FEFD in monitor mode). These events can cause a break interrupt to occur: • A CPU-generated address (the address in the program counter) matches the contents of the break address registers. • Software writes a logic 1 to the BRKA bit in the break status and control register. When a CPU-generated address matches the contents of the break address registers, the break interrupt begins after the CPU completes its current instruction. A return-from-interrupt instruction (RTI) in the break routine ends the break interrupt and returns the MCU to normal operation. Figure 17-1 shows the structure of the break module. Technical Data 246 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Break Module (BREAK) Freescale Semiconductor Break Module (BREAK) Functional Description IAB[15:8] BREAK ADDRESS REGISTER HIGH 8-BIT COMPARATOR IAB[15:0] BKPT (TO SIM) CONTROL 8-BIT COMPARATOR BREAK ADDRESS REGISTER LOW IAB[7:0] Figure 17-1. Break Module Block Diagram Addr. $FE00 Register Name Break Status Register Read: (BSR) Write: Bit 7 6 5 4 3 2 R R R R R R Reset: $FE03 $FE0C $FE0D Break Flag Control Read: Register Write: (BFCR) Reset: Break Address High Read: Register Write: (BRKH) Reset: Break Address low Read: Register Write: (BRKL) Reset: $FE0E Break Status and Control Read: Register Write: (BRKSCR) Reset: Note: Writing a logic 0 clears SBSW. 1 SBSW See note Bit 0 R 0 BCFE R R R R R R R Bit15 Bit14 Bit13 Bit12 Bit11 Bit10 Bit9 Bit8 0 0 0 0 0 0 0 0 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 0 0 0 0 0 0 0 0 BRKE BRKA 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 = Unimplemented R = Reserved Figure 17-2. Break I/O Register Summary MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Break Module (BREAK) Technical Data 247 Break Module (BREAK) 17.4.1 Flag Protection During Break Interrupts The BCFE bit in the break flag control register (BFCR) enables software to clear status bits during the break state. 17.4.2 CPU During Break Interrupts The CPU starts a break interrupt by: • Loading the instruction register with the SWI instruction • Loading the program counter with $FFFC and $FFFD ($FEFC and $FEFD in monitor mode) The break interrupt begins after completion of the CPU instruction in progress. If the break address register match occurs on the last cycle of a CPU instruction, the break interrupt begins immediately. 17.4.3 TIM During Break Interrupts A break interrupt stops the timer counter. 17.4.4 COP During Break Interrupts The COP is disabled during a break interrupt when VREG + VHI is present on the RST pin. 17.5 Low-Power Modes The WAIT and STOP instructions put the MCU in low-powerconsumption standby modes. 17.5.1 Wait Mode If enabled, the break module is active in wait mode. In the break routine, the user can subtract one from the return address on the stack if SBSW is set (see 8.7 Low-Power Modes). Clear the SBSW bit by writing logic 0 to it. Technical Data 248 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Break Module (BREAK) Freescale Semiconductor Break Module (BREAK) Break Module Registers 17.5.2 Stop Mode A break interrupt causes exit from stop mode and sets the SBSW bit in the break status register. See 8.8 SIM Registers. 17.6 Break Module Registers These registers control and monitor operation of the break module: • Break status and control register (BRKSCR) • Break address register high (BRKH) • Break address register low (BRKL) • Break status register (BSR) • Break flag control register (BFCR) 17.6.1 Break Status and Control Register The break status and control register contains break module enable and status bits. Address: $FE0E Bit 7 6 BRKE BRKA 0 0 Read: 5 4 3 2 1 Bit 0 0 0 0 0 0 0 0 0 0 0 0 0 Write: Reset: = Unimplemented Figure 17-3. Break Status and Control Register (BRKSCR) BRKE — Break Enable Bit This read/write bit enables breaks on break address register matches. Clear BRKE by writing a logic 0 to bit 7. Reset clears the BRKE bit. 1 = Breaks enabled on 16-bit address match 0 = Breaks disabled MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Break Module (BREAK) Technical Data 249 Break Module (BREAK) BRKA — Break Active Bit This read/write status and control bit is set when a break address match occurs. Writing a logic 1 to BRKA generates a break interrupt. Clear BRKA by writing a logic 0 to it before exiting the break routine. Reset clears the BRKA bit. 1 = Break address match 0 = No break address match 17.6.2 Break Address Registers The break address registers contain the high and low bytes of the desired breakpoint address. Reset clears the break address registers. Address: $FE0C Bit 7 6 5 4 3 2 1 Bit 0 Bit 15 14 13 12 11 10 9 Bit 8 0 0 0 0 0 0 0 0 Read: Write: Reset: Figure 17-4. Break Address Register High (BRKH) Address: $FE0D Bit 7 6 5 4 3 2 1 Bit 0 Bit 7 6 5 4 3 2 1 Bit 0 0 0 0 0 0 0 0 0 Read: Write: Reset: Figure 17-5. Break Address Register Low (BRKL) 17.6.3 Break Status Register The break status register (BSR) contains a flag to indicate that a break caused an exit from stop or wait mode. This status bit is useful in applications requiring a return to wait or stop mode after exiting from a break interrupt. Technical Data 250 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Break Module (BREAK) Freescale Semiconductor Break Module (BREAK) Break Module Registers Address: $FE00 Bit 7 6 5 4 3 2 R R R R R R Read: 1 Bit 0 SBSW Write: Note(1) Reset: 0 R = Reserved R 1. Writing a logic zero clears SBSW. Figure 17-6. Break Status Register (BSR) SBSW — SIM Break Stop/Wait This read/write bit is set when a break interrupt causes an exit from wait or stop mode. Clear SBSW by writing a logic 0 to it. Reset clears SBSW. 1 = Stop mode or wait mode was exited by break interrupt 0 = Stop mode or wait mode was not exited by break interrupt SBSW can be read within the break state SWI routine. The user can modify the return address on the stack by subtracting one from it. The following code is an example of this. This code works if the H register was stacked in the break interrupt routine. Execute this code at the end of the break interrupt routine. HIBYTE EQU 5 LOBYTE EQU 6 ; If not SBSW, do RTI BRCLR SBSW,BSR, RETURN ; See if wait mode or stop mode ; was exited by break. TST LOBYTE,SP ; If RETURNLO is not zero, BNE DOLO ; then just decrement low byte. DEC HIBYTE,SP ; Else deal with high byte, too. DOLO DEC LOBYTE,SP ; Point to WAIT/STOP opcode. RETURN PULH RTI ; Restore H register. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Break Module (BREAK) Technical Data 251 Break Module (BREAK) 17.6.4 Break Flag Control Register (BFCR) The break control register contains a bit that enables software to clear status bits while the MCU is in a break state. Address: $FE03 Bit 7 6 5 4 3 2 1 Bit 0 BCFE R R R R R R R Read: Write: Reset: 0 R = Reserved Figure 17-7. Break Flag Control Register High (BFCR) BCFE — Break Clear Flag Enable Bit This read/write bit enables software to clear status bits by accessing status registers while the MCU is in a break state. To clear status bits during the break state, the BCFE bit must be set. 1 = Status bits clearable during break 0 = Status bits not clearable during break Technical Data 252 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Break Module (BREAK) Freescale Semiconductor Technical Data — MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 Section 18. Electrical Specifications 18.1 Contents 18.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253 18.3 Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . 254 18.4 Functional Operating Range. . . . . . . . . . . . . . . . . . . . . . . . . . 255 18.5 Thermal Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255 18.6 DC Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . 256 18.7 Control Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257 18.8 Oscillator Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257 18.9 USB DC Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . 258 18.10 USB Low-Speed Source Electrical Characteristics . . . . . . . . 259 18.11 USB Signaling Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260 18.12 TImer Interface Module Characteristics . . . . . . . . . . . . . . . . . 260 18.13 Memory Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261 18.2 Introduction This section contains electrical and timing specifications. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Electrical Specifications Technical Data 253 Electrical Specifications 18.3 Absolute Maximum Ratings Maximum ratings are the extreme limits to which the MCU can be exposed without permanently damaging it. NOTE: This device is not guaranteed to operate properly at the maximum ratings. Refer to 18.6 DC Electrical Characteristics for guaranteed operating conditions. Characteristic(1) Symbol Value Unit Supply voltage VDD –0.3 to +6.0 V Input voltage PTE4/D–, PTE3/D+ RST, IRQ Others VIN VSS – 1.0 to VDD + 0.3 VSS – 0.3 to VDD + 0.3 VSS – 0.3 to VREG + 0.3 V VDD +VHI VSS –0.3 to +11 V I ± 25 mA TSTG –55 to +150 °C Maximum current of PTD0/1 (20-pin package) IOL –25 to +50 mA Maximum current out of VSS IMVSS 100 mA Maximum current into VDD IMVDD 100 mA Mode entry voltage, IRQ pin Maximum current per pin excluding VDD and VSS Storage temperature NOTES: 1. Voltages referenced to VSS NOTE: Technical Data 254 This device contains circuitry to protect the inputs against damage due to high static voltages or electric fields; however, it is advised that normal precautions be taken to avoid application of any voltage higher than maximum-rated voltages to this high-impedance circuit. For proper operation, it is recommended that VIN and VOUT be constrained to the range VSS ≤ (VIN or VOUT) ≤ VREG. Reliability of operation is enhanced if unused inputs are connected to an appropriate logic voltage level (for example, either VSS or VREG). MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Electrical Specifications Freescale Semiconductor Electrical Specifications Functional Operating Range 18.4 Functional Operating Range Characteristic Operating temperature range Operating voltage range Symbol Value Unit TA 0 to 70 °C VDD 4.0 to 5.5 V 18.5 Thermal Characteristics Characteristic Symbol Value Unit Thermal Resistance QFP (44 pins) SOIC (28 pins) SOIC (20 pins) PDIP (20 pins) θJA I/O pin power dissipation PI/O User determined W Power dissipation(1) PD PD = (IDD × VDD) + PI/O = K/(TJ + 273 °C) W Constant(2) K Average junction temperature Maximum junction temperature 95 70 70 70 °C/W PD x (TA + 273 °C) + PD2 × θJA W/°C TJ TA + (PD × θJA) °C TJM 100 °C NOTES: 1. Power dissipation is a function of temperature. 2. K is a constant unique to the device. K can be determined for a known TA and measured PD. With this value of K, PD and TJ can be determined for any value of TA. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Electrical Specifications Technical Data 255 Electrical Specifications 18.6 DC Electrical Characteristics Characteristic(1) Symbol Min Typ(2) Max Unit Regulator output voltage VREG 3.0 3.3 3.6 V Output high voltage (ILoad = –2.0 mA) PTA0–PTA7, PTB0–PTB7, PTC0–PTC7, PTE0–PTE2 VOH VREG –0.8 — — V Output low voltage (ILoad = 1.6 mA) All I/O pins (ILoad = 25 mA) PTD0–PTD1 in ILDD mode (ILoad = 10 mA) PTE3–PTE4 with USB disabled VOL — — — — — — 0.4 0.5 0.4 Input high voltage All ports, OSC1 IRQ, RST VIH 0.7 × VREG 0.7 × VDD — — VREG VDD V Input low voltage All ports, OSC1 IRQ, RST VIL VSS VSS — — 0.3 × VREG 0.3 × VDD V Output low current (VOL = 2.0 V) PTD2–PTD5 in LDD mode IOL 10 13 20 mA — — — — 5.0 4.5 3.0 2.5 7.5 6.5 5.0 4.0 mA mA mA mA — 300 350 µA V VDD supply current, VDD = 5.25V, fOP = 3MHz Run, with low speed USB(3) Run, with USB suspended(3) Wait, with low speed USB(4) Wait, with USB suspended(4) Stop(5) 0 °C to 70°C IDD I/O ports Hi-Z leakage current IIL — — ± 10 µA Input current IIN — — ±1 µA Capacitance Ports (as input or output) COut CIn — — — — 12 8 pF POR re-arm voltage(6) VPOR 0 — 100 mV POR rise-time ramp rate(7) RPOR 0.035 — — V/ms Monitor mode entry voltage VDD+VHI 1.4 × VDD — 2 × VDD V 25 4 1.2 40 5 1.5 55 6 2 2.8 3.3 3.8 Pullup resistors Port A, port B, port C, PTE0–PTE2, RST, IRQ PTE3–PTE4 (with USB module disabled) D– (with USB module enabled) RPU LVI reset VLVR Technical Data 256 kΩ V MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Electrical Specifications Freescale Semiconductor Electrical Specifications Control Timing NOTES: 1. VDD = 4.0 to 5.5 Vdc, VSS = 0 Vdc, TA = TL to TH, unless otherwise noted. 2. Typical values reflect average measurements at midpoint of voltage range, 25 °C only. 3. Run (operating) IDD measured using external square wave clock source (fXCLK = 6 MHz). All inputs 0.2 V from rail. No dc loads. Less than 100 pF on all outputs. CL = 20 pF on OSC2. All ports configured as inputs. OSC2 capacitance linearly affects run IDD. Measured with all modules enabled. 4. Wait IDD measured using external square wave clock source (fXCLK = 6 MHz); all inputs 0.2 V from rail; no dc loads; less than 100 pF on all outputs. CL = 20 pF on OSC2; 15 kΩ ± 5% termination resistors on D+ and D– pins; all ports configured as inputs; OSC2 capacitance linearly affects wait IDD 5. STOP IDD measured with USB in suspend mode; OSC1 grounded; transceiver pullup resistor of 1.5 kΩ ± 5% between VREG and D– and 15 kΩ ± 5% termination resistors on D+ and D– pins; no port pins sourcing current. 6. Maximum is highest voltage that POR is guaranteed. 7. If minimum VREG is not reached before the internal POR reset is released, RST must be driven low externally until minimum VREG is reached. 18.7 Control Timing Characteristic(1) Symbol Min Max Unit Internal operating frequency(2) fOP — 3 MHz RST input pulse width low(3) tIRL 125 — ns NOTES: 1. VDD = 4.0 to 5.5 Vdc; VSS = 0 Vdc; timing shown with respect to 20% VDD and 70% VDD, unless otherwise noted. 2. Some modules may require a minimum frequency greater than dc for proper operation; see appropriate table for this information. 3. Minimum pulse width reset is guaranteed to be recognized. It is possible for a smaller pulse width to cause a reset. 18.8 Oscillator Characteristics Characteristic Symbol Min Typ Max Unit Crystal frequency(1) fXCLK 1 — 6 MHz External clock Reference frequency(1), (2) fXCLK dc — 6 MHz Crystal load capacitance(3) CL — — — Crystal fixed capacitance(3) C1 — 2 × CL — Crystal tuning capacitance(3) C2 — 2 × CL — Feedback bias resistor RB — 10 MΩ — Series resistor(3), (4) RS — — — NOTES: 1. The USB module is designed to function at fXCLK = 6 MHz. 2. No more than 10% duty cycle deviation from 50%. 3. Consult crystal vendor data sheet. 4. Not required for high-frequency crystals. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Electrical Specifications Technical Data 257 Electrical Specifications 18.9 USB DC Electrical Characteristics Characteristic(1) Symbol Conditions Min Hi-Z state data line leakage ILO 0 V 200 mV Differential 0 D– > VOH (min) and D– < VOL (max) (D–) – (D+) > 200 mV Single-ended 0 (SE0) D+ and D– < VOL (max) D+ and D– < VIL (max) Data J state (low speed) Differential 0 Differential 0 Data K state (low speed) Differential 1 Differential 1 Idle state (low speed) NA D– > VIHZ (min) and D+ < VIL (max) Resume state Differential 1 Differential 1 Start of packet (SOP) Data lines switch from Idle to K State End of packet (EOP) SE0 for approximately 2 bit times(1) followed by a J state for 1 bit time SE0 for ≥ 1 bit time(2) followed by a J state for 1 bit time Reset NA D+ and D– < VIL (max) for ≥ 8µs NOTES: 1. The width of EOP is defined in bit times relative to the speed of transmission. 2. The width of EOP is defined in bit times relative to the device type receiving the EOP. The bit time is approximate. 18.12 TImer Interface Module Characteristics Characteristic Input capture pulse width Input clock pulse width Technical Data 260 Symbol Min Max tTIH, tTIL 1/fOP — tTCH, tTCL (1/fOP) + 5ns — Unit MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Electrical Specifications Freescale Semiconductor Electrical Specifications Memory Characteristics 18.13 Memory Characteristics Characteristic RAM data retention voltage Symbol Min Max Unit VRDR 1.3 — V FLASH block size — 512 Bytes FLASH programming size — 64 Bytes FLASH read bus clock frequency fRead(1) 32 k 8.4 M Hz FLASH block erase time tErase(2) 2 — ms FLASH mass erase time tMErase(3) 2 — ms FLASH PGM/ERASE to HVEN set up time tnvs 5 — µs FLASH high-voltage hold time tnvh 5 — µs FLASH high-voltage hold time (mass erase) tnvhl 100 — µs FLASH program hold time tpgs 10 — µs FLASH program time tPROG 20 — µs FLASH return to read time trcv(4) 1 — µs FLASH cumulative program hv period tHV(5) — 25 ms FLASH row erase endurance(6) — 10k — Cycles FLASH row program endurance(7) — 10k — Cycles FLASH data retention time(8) — 10 — Years NOTES: 1. fREAD is defined as the frequency range for which the FLASH memory can be read. 2. If the page erase time is longer than tErase (Min), there is no erase-disturb, but it reduced the endurance of the flash memory 3. If the mass erase time is longer than tMErase (Min), there is no erase-disturb, but it reduced the endurance of the flash memory 4. trcv is defined as the time it need before start the read of the flash after turn off the HVEN bit 5. tHV is defined as the cumulative high voltage programming time to the same row before next erase 6. The minimum row endurance value specifies each row of the FLASH memory is guaranteed to work for at least this many erase / program cycles. 7. The minimum row endurance value specifies each row of the FLASH memory is guaranteed to work for at least this many erase / program cycles. 8. The FLASH is guaranteed to retain data over the entire operating temperature range for at least the minimum time specified. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Electrical Specifications Technical Data 261 Electrical Specifications Technical Data 262 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Electrical Specifications Freescale Semiconductor Technical Data — MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 Section 19. Mechanical Specifications 19.1 Contents 19.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263 19.3 44-Pin Plastic Quad Flat Pack (QFP) . . . . . . . . . . . . . . . . . . . 264 19.4 28-Pin Small Outline Integrated Circuit (SOIC) . . . . . . . . . . . 265 19.5 20-Pin Dual In-Line Package (PDIP) . . . . . . . . . . . . . . . . . . . 265 19.6 20-Pin Small Outline Integrated Circuit (SOIC) . . . . . . . . . . . 266 19.2 Introduction This section gives the dimensions for: • 44-pin plastic quad flat pack (case 824A) • 28-pin small outline integrated circuit package (case 751F) • 20-pin plastic dual in-line package (case 738) • 20-pin small outline integrated circuit package (case 751D) MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Mechanical Specifications Technical Data 263 Mechanical Specifications 19.3 44-Pin Plastic Quad Flat Pack (QFP) B L B 33 23 22 S D S V F BASE METAL 0.20 (0.008) DETAIL A DETAIL A M C A–B S S H A–B 0.20 (0.008) B L –B– M –A– D –A–, –B–, –D– 0.05 (0.002) A–B 34 J N D 44 0.20 (0.008) 12 1 11 M C A–B S D S SECTION B–B VIEW ROTATED 90° –D– A 0.20 (0.008) M H A–B S D S S D S 0.05 (0.002) A–B S 0.20 (0.008) M C A–B M DETAIL C C E –H– –C– DATUM PLANE 0.10 (0.004) H SEATING PLANE G NOTES: 1. DIMENSIONING AND TOLERANCING PER ANSI Y14.5M, 1982. 2. CONTROLLING DIMENSION: MILLIMETER. 3. DATUM PLANE –H– IS LOCATED AT BOTTOM OF LEAD AND IS COINCIDENT WITH THE LEAD WHERE THE LEAD EXITS THE PLASTIC BODY AT THE BOTTOM OF THE PARTING LINE. 4. DATUMS –A–, –B– AND –D– TO BE DETERMINED AT DATUM PLANE –H–. 5. DIMENSIONS S AND V TO BE DETERMINED AT SEATING PLANE –C–. 6. DIMENSIONS A AND B DO NOT INCLUDE MOLD PROTRUSION. ALLOWABLE PROTRUSION IS 0.25 (0.010) PER SIDE. DIMENSIONS A AND B DO INCLUDE MOLD MISMATCH AND ARE DETERMINED AT DATUM PLANE –H–. 7. DIMENSION D DOES NOT INCLUDE DAMBAR PROTRUSION. ALLOWABLE DAMBAR PROTRUSION SHALL BE 0.08 (0.003) TOTAL IN EXCESS OF THE D DIMENSION AT MAXIMUM MATERIAL CONDITION. DAMBAR CANNOT BE LOCATED ON THE LOWER RADIUS OR THE FOOT. M DIM A B C D E F G H J K L M N Q R S T U V W X M T DATUM PLANE –H– R K W Q X DETAIL C MILLIMETERS MIN MAX 9.90 10.10 9.90 10.10 2.10 2.45 0.30 0.45 2.00 2.10 0.30 0.40 0.80 BSC — 0.25 0.13 0.23 0.65 0.95 8.00 REF 5° 10° 0.13 0.17 0° 7° 0.13 0.30 12.95 13.45 0.13 — 0° — 12.95 13.45 0.40 — 1.6 REF INCHES MIN MAX 0.390 0.398 0.390 0.398 0.083 0.096 0.012 0.018 0.079 0.083 0.012 0.016 0.031 BSC — 0.010 0.005 0.009 0.026 0.037 0.315 REF 5° 10° 0.005 0.007 0° 7° 0.005 0.012 0.510 0.530 0.005 — 0° — 0.510 0.530 0.016 — 0.063 REF Figure 19-1. 44-Pin QFP (Case 824A) Technical Data 264 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Mechanical Specifications Freescale Semiconductor Mechanical Specifications 28-Pin Small Outline Integrated Circuit (SOIC) 19.4 28-Pin Small Outline Integrated Circuit (SOIC) NOTES: 1. DIMENSIONING AND TOLERANCING PER ANSI Y14.5M, 1982. 2. CONTROLLING DIMENSION: MILLIMETER. 3. DIMENSION A AND B DO NOT INCLUDE MOLD PROTRUSION. 4. MAXIMUM MOLD PROTRUSION 0.15 (0.006) PER SIDE. 5. DIMENSION D DOES NOT INCLUDE DAMBAR PROTRUSION. ALLOWABLE DAMBAR PROTRUSION SHALL BE 0.13 (0.005) TOTAL IN EXCESS OF D DIMENSION AT MAXIMUM MATERIAL CONDITION. -A15 28 14X -B1 P 0.010 (0.25) M B M 14 28X D 0.010 (0.25) M T A S B M S R DIM A B C D F G J K M P R X 45 C 26X -T- G SEATING PLANE K F J MILLIMETERS MIN MAX 17.80 18.05 7.40 7.60 2.35 2.65 0.35 0.49 0.41 0.90 1.27 BSC 0.23 0.32 0.13 0.29 0° 8° 10.01 10.55 0.25 0.75 INCHES MIN MAX 0.701 0.711 0.292 0.299 0.093 0.104 0.014 0.019 0.016 0.035 0.050 BSC 0.009 0.013 0.005 0.011 0° 8° 0.395 0.415 0.010 0.029 Figure 19-2. 28-Pin SOIC (Case 751F) 19.5 20-Pin Dual In-Line Package (PDIP) –A– 20 11 1 10 NOTES: 1. DIMENSIONING AND TOLERANCING PER ANSI Y14.5M, 1982. 2. CONTROLLING DIMENSION: INCH. 3. DIMENSION L TO CENTER OF LEAD WHEN FORMED PARALLEL. 4. DIMENSION B DOES NOT INCLUDE MOLD FLASH. B L C –T– K SEATING PLANE M N E G F J D 20 PL 0.25 (0.010) 20 PL 0.25 (0.010) M T A M T B M M DIM A B C D E F G J K L M N INCHES MIN MAX 1.010 1.070 0.240 0.260 0.150 0.180 0.015 0.022 0.050 BSC 0.050 0.070 0.100 BSC 0.008 0.015 0.110 0.140 0.300 BSC 0_ 15 _ 0.020 0.040 MILLIMETERS MIN MAX 25.66 27.17 6.10 6.60 3.81 4.57 0.39 0.55 1.27 BSC 1.27 1.77 2.54 BSC 0.21 0.38 2.80 3.55 7.62 BSC 0_ 15_ 0.51 1.01 Figure 19-3. 20-Pin PDIP (Case 738) MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Mechanical Specifications Technical Data 265 Mechanical Specifications 19.6 20-Pin Small Outline Integrated Circuit (SOIC) NOTES: 1. DIMENSIONING AND TOLERANCING PER ANSI Y14.5M, 1982. 2. CONTROLLING DIMENSION: MILLIMETER. 3. DIMENSIONS A AND B DO NOT INCLUDE MOLD PROTRUSION. 4. MAXIMUM MOLD PROTRUSION 0.150 (0.006) PER SIDE. 5. DIMENSION D DOES NOT INCLUDE DAMBAR PROTRUSION. ALLOWABLE DAMBAR PROTRUSION SHALL BE 0.13 (0.005) TOTAL IN EXCESS OF D DIMENSION AT MAXIMUM MATERIAL CONDITION. –A– 20 11 –B– 10X P 0.010 (0.25) 1 M B M 10 20X D 0.010 (0.25) M T A B S J S F R X 45 _ C –T– 18X G K SEATING PLANE DIM A B C D F G J K M P R MILLIMETERS MIN MAX 12.65 12.95 7.40 7.60 2.35 2.65 0.35 0.49 0.50 0.90 1.27 BSC 0.25 0.32 0.10 0.25 0_ 7_ 10.05 10.55 0.25 0.75 INCHES MIN MAX 0.499 0.510 0.292 0.299 0.093 0.104 0.014 0.019 0.020 0.035 0.050 BSC 0.010 0.012 0.004 0.009 0_ 7_ 0.395 0.415 0.010 0.029 M Figure 19-4. 20-Pin SOIC (Case 751D) Technical Data 266 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Mechanical Specifications Freescale Semiconductor Technical Data — MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 Section 20. Ordering Information 20.1 Contents 20.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267 20.3 MC Order Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267 20.2 Introduction This section contains ordering numbers for the MC68HC908JB8. 20.3 MC Order Numbers Table 20-1. MC Order Numbers Package Operating Temperature Range MC68HC908JB8JP 20-pin PDIP 0 to +70 °C MC68HC908JB8JDW 20-pin SOIC 0 to +70 °C MC68HC908JB8ADW 28-pin SOIC 0 to +70 °C MC68HC908JB8FB 44-pin QFP 0 to +70 °C MC68HC908JB8JPE 20-pin PDIP 0 to +70 °C MC908JB8JDWE 20-pin SOIC 0 to +70 °C MC908JB8ADWE 28-pin SOIC 0 to +70 °C MC908JB8FBE 44-pin QFP 0 to +70 °C MC Order Number MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor Ordering Information Compliance — Pb-Free and RoHS compliant. Technical Data 267 Ordering Information Technical Data 268 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Ordering Information Freescale Semiconductor Technical Data — MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 Appendix A. MC68HC08JB8 A.1 Contents A.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270 A.3 MCU Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270 A.4 Memory Map. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270 A.5 Reserved Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273 A.6 Monitor ROM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .273 A.7 Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273 A.7.1 DC Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . .274 A.7.2 Memory Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . 275 A.8 MC68HC08JB8 Order Numbers . . . . . . . . . . . . . . . . . . . . . . . 275 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor MC68HC08JB8 Technical Data 269 MC68HC08JB8 A.2 Introduction This section introduces the MC68HC08JB8, the ROM part equivalent to the MC68HC908JB8. The entire data book apply to this ROM device, with exceptions outlined in this appendix. Table A-1. Summary of MC68HC08JB8 and MC68HC908JB8 Differences MC68HC08JB8 MC68HC908JB8 Memory ($DC00–$FBFF) 8,192 bytes ROM 8,192 bytes FLASH User vectors ($FFF0–$FFFF) 16 bytes ROM 16 bytes FLASH Registers at $FE08 and $FF09 Not used; locations are reserved. FLASH related registers. $FE08 — FLCR $FF09 — FLBPR Monitor ROM ($FC00–$FDFF and $FE10–$FFDF) $FC00–$FDFF: Not used. $FE10–$FFDF: Used for testing purposes only. Used for testing and FLASH programming/erasing. A.3 MCU Block Diagram Figure A-1 shows the block diagram of the MC68HC08JB8. A.4 Memory Map The MC68HC08JB8 has 8,192 bytes of user ROM from $DC00 to $FBFF, and 16 bytes of user ROM vectors from $FFF0 to $FFFF. On the MC68HC908JB8, these memory locations are FLASH memory. Figure A-2 shows the memory map of the MC68HC08JB8. Technical Data 270 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 MC68HC08JB8 Freescale Semiconductor PTA PTB PTC PTC7–PTC0 (3) PTD PTD7–PTD6 (4) PTD5–PTD2 (4) (5) DDRA DDRB PTB7–PTB0 (3) DDRC CPU REGISTERS PTA7/KBA7 (3) : PTA0/KBA0 (3) ARITHMETIC/LOGIC UNIT (ALU) KEYBOARD INTERRUPT MODULE CONTROL AND STATUS REGISTERS — 64 BYTES TIMER INTERFACE MODULE USER ROM — 8,192 BYTES USER RAM — 256 BYTES BREAK MODULE MONITOR ROM — 464 BYTES LOW VOLTAGE INHIBIT MODULE OSC1 OSC2 DDRD USER ROM VECTORS — 16 BYTES PTD1–PTD0 (4) (6) POWER-ON RESET MODULE OSCILLATOR PTE4/D– (3) (4) (5) (1), (3) IRQ SYSTEM INTEGRATION MODULE PTE3/D+ COMPUTER OPERATING PROPERLY MODULE IRQ MODULE USB MODULE VDD USB ENDPOINT 0, 1, 2 POWER PTE RST DDRE (1), (2) LS USB TRANSCEIVER MC68HC08JB8 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor INTERNAL BUS M68HC08 CPU (3) (4) (5) PTE2/TCH1 (3) PTE1/TCH0 (3) PTE0/TCLK (3) VSS VREG (3.3 V) INTERNAL VOLTAGE REGULATOR (1) Pins have 5V logic. (2) Pins have integrated pullup device. (3) Pins have software configurable pull-up device. (4) Pins are open-drain when configured as output. (5) Pins have 10mA sink capability. (6) Pins have 25mA sink capability. Figure A-1. MC68HC08JB8 Block Diagram MC68HC08JB8 271 Technical Data Shaded blocks indicate differences to MC68HC908JB8 MC68HC08JB8 $0000 ↓ $003F I/O Registers 64 Bytes $0040 ↓ $013F RAM 256 Bytes $0140 ↓ $DBFF Unimplemented 56,000 Bytes $DC00 ↓ $FBFF ROM 8,192 Bytes $FC00 ↓ $FDFF Unimplemented 512 Bytes $FE00 Break Status Register (BSR) $FE01 Reset Status Register (RSR) $FE02 Reserved $FE03 Break Flag Control Register (BFCR) $FE04 Interrupt Status Register 1 (INT1) $FE05 Reserved $FE06 Reserved $FE07 Reserved $FE08 Reserved $FE09 Reserved $FE0A Reserved $FE0B Reserved $FE0C Break Address High Register (BRKH) $FE0D Break Address Low Register (BRKL) $FE0E Break Status and Control Register (BRKSCR) $FE0F Reserved $FE10 ↓ $FFDF Monitor ROM 464 Bytes $FFE0 ↓ $FFEF Reserved 16 Bytes $FFF0 ↓ $FFFF ROM Vectors 16 Bytes Figure A-2. MC68HC08JB8 Memory Map Technical Data 272 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 MC68HC08JB8 Freescale Semiconductor MC68HC08JB8 A.5 Reserved Registers The two registers at $FE08 and $FE09 are reserved locations on the MC68HC08JB8. On the MC68HC908JB8, these two locations are the FLASH control register and the FLASH block protect register respectively. A.6 Monitor ROM The monitor program (monitor ROM: $FE10–$FFDF) on the MC68HC08JB8 is for device testing only. $FC00–$FDFF are unused. A.7 Electrical Specifications Electrical specifications for the MC68HC908JB8 apply to the MC68HC08JB8, except for the parameters indicated below. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor MC68HC08JB8 Technical Data 273 MC68HC08JB8 A.7.1 DC Electrical Characteristics Characteristic(1) Symbol Min Typ(2) Max Unit Regulator output voltage VREG 3.0 3.3 3.6 V Output high voltage (ILoad = –2.0 mA) PTA0–PTA7, PTB0–PTB7, PTC0–PTC7, PTE0–PTE2 VOH VREG –0.8 — — V Output low voltage (ILoad = 1.6 mA) All I/O pins (ILoad = 25 mA) PTD0–PTD1 in ILDD mode (ILoad = 10 mA) PTE3–PTE4 with USB disabled VOL — — — — — — 0.4 0.5 0.4 Input high voltage All ports, OSC1 IRQ, RST VIH 0.7 × VREG 0.7 × VDD — — VREG VDD V Input low voltage All ports, OSC1 IRQ, RST VIL VSS VSS — — 0.3 × VREG 0.3 × VDD V Output low current (VOL = 2.0 V) PTD2–PTD5 in LDD mode IOL 17 22 27 mA — — — — 5.0 4.5 3.0 2.5 7.5 6.5 5.0 4.0 mA mA mA mA — 30 100 µA V VDD supply current, VDD = 5.25V, fOP = 3MHz Run, with low speed USB(3) Run, with USB suspended(3) Wait, with low speed USB(4) Wait, with USB suspended(4) Stop(5) 0 °C to 70°C IDD I/O ports Hi-Z leakage current IIL — — ± 10 µA Input current IIN — — ±1 µA Capacitance Ports (as input or output) COut CIn — — — — 12 8 pF POR re-arm voltage(6) VPOR 0 — 100 mV POR rise-time ramp rate(7) RPOR 0.035 — — V/ms Monitor mode entry voltage VDD+VHI 1.4 × VDD 2 × VDD V Pullup resistors Port A, port B, port C, PTE0–PTE2, RST, IRQ PTE3–PTE4 (with USB module disabled) D– (with USB module enabled) RPU LVI reset VLVR Technical Data 274 25 4 1.2 40 5 1.5 55 6 2.0 2.4 2.7 3.0 kΩ V MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 MC68HC08JB8 Freescale Semiconductor MC68HC08JB8 NOTES: 1. VDD = 4.0 to 5.5 Vdc, VSS = 0 Vdc, TA = TL to TH, unless otherwise noted. 2. Typical values reflect average measurements at midpoint of voltage range, 25 °C only. 3. Run (operating) IDD measured using external square wave clock source (fXCLK = 6 MHz). All inputs 0.2 V from rail. No dc loads. Less than 100 pF on all outputs. CL = 20 pF on OSC2. All ports configured as inputs. OSC2 capacitance linearly affects run IDD. Measured with all modules enabled. 4. Wait IDD measured using external square wave clock source (fXCLK = 6 MHz); all inputs 0.2 V from rail; no dc loads; less than 100 pF on all outputs. CL = 20 pF on OSC2; 15 kΩ ± 5% termination resistors on D+ and D– pins; all ports configured as inputs; OSC2 capacitance linearly affects wait IDD 5. STOP IDD measured with USB in suspend mode; OSC1 grounded; transceiver pullup resistor of 1.5 kΩ ± 5% between VREG and D– pins and 15 kΩ ± 5% termination resistor on D+ pin; no port pins sourcing current. 6. Maximum is highest voltage that POR is guaranteed. 7. If minimum VREG is not reached before the internal POR reset is released, RST must be driven low externally until minimum VREG is reached. A.7.2 Memory Characteristics Characteristic Symbol Min Max Unit VRDR 1.3 — V RAM data retention voltage Notes: Since MC68HC08JB8 is a ROM device, FLASH memory electrical characteristics do not apply. A.8 MC68HC08JB8 Order Numbers These part numbers are generic numbers only. To place an order, ROM code must be submitted to the ROM Processing Center (RPC). Table A-2. MC68HC08JB8 Order Numbers Package Operating Temperature Range MC68HC08JB8JP 20-pin PDIP 0 to +70 °C MC68HC08JB8JDW 20-pin SOIC 0 to +70 °C MC68HC08JB8ADW 28-pin SOIC 0 to +70 °C MC68HC08JB8FB 44-pin QFP 0 to +70 °C MC Order Number MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor MC68HC08JB8 Technical Data 275 MC68HC08JB8 Technical Data 276 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 MC68HC08JB8 Freescale Semiconductor Technical Data — MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 Appendix B. MC68HC08JT8 B.1 Contents B.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278 B.3 MCU Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278 B.4 Memory Map. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278 B.5 Power Supply Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 281 B.6 Reserved Register Bit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 281 B.7 Reserved Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 281 B.8 Monitor ROM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .282 B.9 Universal Serial Bus Module. . . . . . . . . . . . . . . . . . . . . . . . . . 282 B.10 Low-Voltage Inhibit Module . . . . . . . . . . . . . . . . . . . . . . . . . . 282 B.11 Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 282 B.11.1 Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . 282 B.11.2 Functional Operating Range . . . . . . . . . . . . . . . . . . . . . . .283 B.11.3 DC Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . .283 B.11.4 Control Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 284 B.11.5 Memory Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . 284 B.12 MC68HC08JT8 Order Numbers . . . . . . . . . . . . . . . . . . . . . . . 284 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor MC68HC08JT8 Technical Data 277 MC68HC08JT8 B.2 Introduction This section introduces the MC68HC08JT8, a low-voltage ROM part version to the MC68HC908JB8. The entire data book apply to this ROM device, with exceptions outlined in this appendix. Table B-1. Summary of MC68HC08JT8 and MC68HC908JB8 Differences MC68HC08JT8 MC68HC908JB8 Memory ($DC00–$FBFF) 8,192 bytes ROM 8,192 bytes FLASH User vectors ($FFF0–$FFFF) 16 bytes ROM 16 bytes FLASH Registers at $FE08 and $FF09 Not used; locations are reserved FLASH related registers. $FE08 — FLCR $FF09 — FLBPR Bit 4 at CONFIG ($001F) Not used; bit is reserved. LVID: low-voltage inhibit disable bit Monitor ROM ($FC00–$FDFF and $FE10–$FFDF) $FC00–$FDFF: Not used. $FE10–$FFDF: Used for testing purposes only. Used for testing and FLASH programming/erasing. Low voltage inhibit module Not available (disabled) Available Universal Serial Bus (USB) module Not available. User should set the SUSPND bit to logic 1 to reduce power consumption. Available On-chip 3.3V regulator Not available (disabled) Available Operating voltage 2.0 to 3.6V 4.0 to 5.5V Operating frequency fOPMAX = 2.5MHz at 2V fOPMAX = 3MHz at 3V 3MHz B.3 MCU Block Diagram Figure B-1 shows the block diagram of the MC68HC08JT8. B.4 Memory Map The MC68HC08JT8 has 8,192 bytes of user ROM from $DC00 to $FBFF, and 16 bytes of user ROM vectors from $FFF0 to $FFFF. On the MC68HC908JB8, these memory locations are FLASH memory. Figure B-2 shows the memory map of the MC68HC08JT8. Technical Data 278 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 MC68HC08JT8 Freescale Semiconductor PTA PTB PTC PTC7–PTC0 (3) PTD PTD7–PTD6 (4) PTD5–PTD2 (4) (5) DDRA DDRB PTB7–PTB0 (3) DDRC CPU REGISTERS PTA7/KBA7 (3) : PTA0/KBA0 (3) ARITHMETIC/LOGIC UNIT (ALU) KEYBOARD INTERRUPT MODULE CONTROL AND STATUS REGISTERS — 64 BYTES TIMER INTERFACE MODULE USER ROM — 8,192 BYTES USER RAM — 256 BYTES BREAK MODULE MONITOR ROM — 464 BYTES DISABLED LOW VOLTAGE INHIBIT MODULE OSC1 OSC2 DDRD USER ROM VECTORS — 16 BYTES PTD1–PTD0 (4) (6) POWER-ON RESET MODULE OSCILLATOR PTE4 (3) (4) (5) (1), (3) IRQ SYSTEM INTEGRATION MODULE PTE3 COMPUTER OPERATING PROPERLY MODULE IRQ MODULE NOT AVAILABLE USB MODULE VDD USB ENDPOINT 0, 1, 2 POWER PTE RST DDRE (1), (2) LS USB TRANSCEIVER MC68HC08JT8 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor INTERNAL BUS M68HC08 CPU (3) (4) (5) PTE2/TCH1 (3) PTE1/TCH0 (3) PTE0/TCLK (3) VSS DISABLED VREG (3.3 V) INTERNAL VOLTAGE REGULATOR (1) Pins have 5V logic. (2) Pins have integrated pullup device. (3) Pins have software configurable pull-up device. (4) Pins are open-drain when configured as output. (5) Pins have 10mA sink capability. (6) Pins have 25mA sink capability. Figure B-1. MC68HC08JT8 Block Diagram MC68HC08JT8 279 Technical Data Shaded blocks indicate differences to MC68HC908JB8 MC68HC08JT8 $0000 ↓ $003F I/O Registers 64 Bytes $0040 ↓ $013F RAM 256 Bytes $0140 ↓ $DBFF Unimplemented 56,000 Bytes $DC00 ↓ $FBFF ROM 8,192 Bytes $FC00 ↓ $FDFF Unimplemented 512 Bytes $FE00 Break Status Register (BSR) $FE01 Reset Status Register (RSR) $FE02 Reserved $FE03 Break Flag Control Register (BFCR) $FE04 Interrupt Status Register 1 (INT1) $FE05 Reserved $FE06 Reserved $FE07 Reserved $FE08 Reserved $FE09 Reserved $FE0A Reserved $FE0B Reserved $FE0C Break Address High Register (BRKH) $FE0D Break Address Low Register (BRKL) $FE0E Break Status and Control Register (BRKSCR) $FE0F Reserved $FE10 ↓ $FFDF Monitor ROM 464 Bytes $FFE0 ↓ $FFEF Reserved 16 Bytes $FFF0 ↓ $FFFF ROM Vectors 16 Bytes Figure B-2. MC68HC08JT8 Memory Map Technical Data 280 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 MC68HC08JT8 Freescale Semiconductor MC68HC08JT8 B.5 Power Supply Pins The MC68HC08JT8 is design for low voltage operation. Connect VDD and VREG for normal operation. The VREG voltage regulator is disabled on the MC68HC08JT8. MCU VDD VREG VSS CBYPASS 0.1 µF + CBULK 10 µF VDD NOTE: Values shown are typical values. Figure B-3. Power Supply Bypassing B.6 Reserved Register Bit Bit 4 of the configuration register ($001F) is a reserved bit on the MC68HC08JT8. The bit will always read as zero. On the MC68HC908JB8, bit 4 of the configuration register is the lowvoltage inhibit disable bit, LVID. B.7 Reserved Registers The two registers at $FE08 and $FE09 are reserved locations on the MC68HC08JT8. On the MC68HC908JB8, these two locations are the FLASH control register and the FLASH block protect register respectively. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor MC68HC08JT8 Technical Data 281 MC68HC08JT8 B.8 Monitor ROM The monitor program (monitor ROM: $FE10–$FFDF) on the MC68HC08JT8 is for device testing only. $FC00–$FDFF are unused. B.9 Universal Serial Bus Module The USB module is designed for operation with VDD = 4V to 5.5V, therefore, it should not be used on the MC68HC08JT8 device. To further reduce current consumption in stop mode, set the SUSPND bit in the USB interrupt register 0 (UIR0) to logic 1. Other USB registers should be left in their default state. B.10 Low-Voltage Inhibit Module The LVI module is disabled on the MC68HC08JT8. B.11 Electrical Specifications Electrical specifications for the MC68HC908JB8 apply to the MC68HC08JT8, except for the parameters indicated below. B.11.1 Absolute Maximum Ratings Characteristic(1) Symbol Value Unit Supply voltage VDD –0.3 to +3.9 V Input voltage VIN VSS – 0.3 to VDD + 0.3 V I ± 25 mA TSTG –55 to +150 °C Maximum current of PTD0/1 (20-pin package) IOL –15 to +30 mA Maximum current out of VSS IMVSS 100 mA Maximum current into VDD IMVDD 100 mA Maximum current per pin excluding VDD and VSS Storage temperature NOTES: 1. Voltages referenced to VSS. Technical Data 282 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 MC68HC08JT8 Freescale Semiconductor MC68HC08JT8 B.11.2 Functional Operating Range Characteristic Symbol Value Unit TA 0 to 70 °C VDD 2.0 to 3.6 V Operating temperature range Operating voltage range B.11.3 DC Electrical Characteristics Characteristic(1) Symbol Min Typ(2) Max Unit Output high voltage (ILoad = –1.6 mA) PTA0–PTA7, PTB0–PTB7, PTC0–PTC7, PTE0–PTE2 VOH VDD –0.4 — — V Output low voltage (ILoad = 1.6 mA) All I/O pins (ILoad = 15 mA) PTD0–PTD1 in ILDD mode (ILoad = 5 mA) PTE3–PTE4 VOL — — — — — — 0.4 0.5 0.4 Input high voltage All ports, OSC1, IRQ, RST VIH 0.7 × VDD — VDD V Input low voltage All ports, OSC1, IRQ, RST VIL VSS — 0.3 × VDD V Output low current (VOL = 2.0 V)(3) PTD2–PTD5 in LDD mode (VDD = 2V) PTD2–PTD5 in LDD mode (VDD = 3V) IOL — — 6 16 — — mA — — 3.5 2.5 6.5 4.5 mA mA — 20 30 µA V VDD supply current, VDD = 3V, fOP = 3MHz Run(4) Wait(5) Stop(6) 0 °C to 70°C IDD I/O ports Hi-Z leakage current IIL — — ± 10 µA Input current IIN — — ±1 µA Capacitance Ports (as input or output) COut CIn — — — — 12 8 pF POR re-arm voltage(7) VPOR 0 — 100 mV POR rise-time ramp rate RPOR 0.02 — — V/ms VDD+VHI 1.4 × VDD 2 × VDD V RPU 25 4 55 6 kΩ kΩ Monitor mode entry voltage Pullup resistors Port A, port B, port C, PTE0–PTE2, RST, IRQ PTE3–PTE4 MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 Freescale Semiconductor MC68HC08JT8 40 5 Technical Data 283 MC68HC08JT8 NOTES: 1. VDD = 2.0 to 3.6 Vdc, VSS = 0 Vdc, TA = TL to TH, unless otherwise noted. 2. Typical values reflect average measurements at 3V, 25 °C only. 3. In LDD mode, the specified IOL is achieved when the external pullup voltage is equal to or higher than the voltage: VOL + voltage dropped across LED. 4. Run (operating) IDD measured using external square wave clock source (fXCLK = 6 MHz). All inputs 0.2 V from rail. No dc loads. Less than 100 pF on all outputs. CL = 20 pF on OSC2. All ports configured as inputs. OSC2 capacitance linearly affects run IDD. Measured with all modules enabled. 5. Wait IDD measured using external square wave clock source (fXCLK = 6 MHz). All inputs 0.2 V from rail. No dc loads. Less than 100 pF on all outputs. CL = 20 pF on OSC2. All ports configured as inputs. OSC2 capacitance linearly affects wait IDD. 6. Stop IDD measured with OSC1 grounded; no port pins sourcing current. 7. Maximum is highest voltage that POR is guaranteed. B.11.4 Control Timing Characteristic Symbol Min Max Unit fOP — — 2.5 3.0 MHz MHz Symbol Min Max Unit VRDR 1.3 — V Internal operating frequency VDD = 2.0V VDD = 3.0V B.11.5 Memory Characteristics Characteristic RAM data retention voltage NOTES: Since MC68HC08JT8 is a ROM device, FLASH memory electrical characteristics do not apply. B.12 MC68HC08JT8 Order Numbers These part numbers are generic numbers only. To place an order, ROM code must be submitted to the ROM Processing Center (RPC). Table B-2. MC68HC08JT8 Order Numbers Package Operating Temperature Range MC68HC08JT8ADW 28-pin SOIC 0 to +70 °C MC68HC08JT8FB 44-pin QFP 0 to +70 °C MC68HC08JT8FBE 44-pin QFP 0 to +70 °C MC Order Number Technical Data 284 Compliance — Pb-Free and RoHS compliant. MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3 MC68HC08JT8 Freescale Semiconductor How to Reach Us: Home Page: www.freescale.com RoHS-compliant and/or Pb- free versions of Freescale products have the functionality and electrical characteristics of their non-RoHS-compliant and/or non-Pb- free counterparts. For further information, see http://www.freescale.com or contact your Freescale sales representative. E-mail: support@freescale.com For information on Freescale.s Environmental Products program, go to http://www.freescale.com/epp. USA/Europe or Locations Not Listed: Freescale Semiconductor Technical Information Center, CH370 1300 N. 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