MC68HC908BD48IB

MC68HC908BD48 Data Sheet M68HC08 Microcontrollers MC68HC908BD48/D Rev. 2 9/2003 MOTOROLA.COM/SEMICONDUCTORS MC68HC908BD48 Data Sheet 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://motorola.com/semiconductors/ 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. Motorola and the Stylized M Logo are registered trademarks of Motorola, Inc. DigitalDNA is a trademark of Motorola, Inc. This product incorporates SuperFlash® technology licensed from SST. MC68HC908BD48 — Rev. 2.0 MOTOROLA © Motorola, Inc., 2003 Data Sheet 3 Revision History Revision History Date Revision Level Page Number(s) Description Incorporated addendum to rev. 1.0 data sheet. Removed 28-pin PDIP references. 9/2003 Data Sheet 4 2 Section 10. Timer Interface Module (TIM) — Timer discrepancies corrected throughout this section. 125 Section 22. Mechanical Specifications — Replaced incorrect 44-pin QFP drawing, case 824E to case 824A. 283 Section 9. Monitor ROM (MON) — Updated Figure 9-1 . Monitor Mode Circuit. 117 MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet – MC68HC908BD48 List of Sections Section 1. General Description . . . . . . . . . . . . . . . . . . . . 25 Section 2. Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Section 3. Random-Access Memory (RAM) . . . . . . . . . . 53 Section 4. FLASH Memory . . . . . . . . . . . . . . . . . . . . . . . . 55 Section 5. Configuration Register (CONFIG) . . . . . . . . . 63 Section 6. Central Processor Unit (CPU) . . . . . . . . . . . . 67 Section 7. System Integration Module (SIM) . . . . . . . . . 87 Section 8. Oscillator (OSC) . . . . . . . . . . . . . . . . . . . . . . 111 Section 9. Monitor ROM (MON) . . . . . . . . . . . . . . . . . . . 115 Section 10. Timer Interface Module (TIM) . . . . . . . . . . . 125 Section 11. Pulse Width Modulator (PWM) . . . . . . . . . . 147 Section 12. Analog-to-Digital Converter (ADC) . . . . . . 153 Section 13. Universal Serial Bus Module (USB) . . . . . . 163 Section 14. Multi-Master IIC Interface (MMIIC) . . . . . . . 179 Section 15. DDC12AB Interface . . . . . . . . . . . . . . . . . . . 193 Section 16. Sync Processor . . . . . . . . . . . . . . . . . . . . . . 209 Section 17. Input/Output (I/O) Ports . . . . . . . . . . . . . . . 229 Section 18. External Interrupt (IRQ) . . . . . . . . . . . . . . . 251 Section 19. Computer Operating Properly (COP) . . . . 257 Section 20. Break Module (BRK) . . . . . . . . . . . . . . . . . . 263 Section 21. Electrical Specifications. . . . . . . . . . . . . . . 271 Section 22. Mechanical Specifications . . . . . . . . . . . . . 283 Section 23. Ordering Information . . . . . . . . . . . . . . . . . 285 MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet List of Sections 5 List of Sections Data Sheet 6 MC68HC908BD48 — Rev. 2.0 List of Sections MOTOROLA Data Sheet – MC68HC908BD48 Table of Contents Section 1. General Description 1.1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25 1.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 1.3 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 1.4 MCU Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 1.5 Pin Assignments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 1.6 Pin Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31 Section 2. Memory Map 2.1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35 2.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 2.3 Unimplemented Memory Locations . . . . . . . . . . . . . . . . . . . . . 35 2.4 Reserved Memory Locations . . . . . . . . . . . . . . . . . . . . . . . . . . 36 2.5 Input/Output (I/O) Section. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Section 3. Random-Access Memory (RAM) 3.1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53 3.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 3.3 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53 Section 4. FLASH Memory 4.1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55 4.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Table of Contents 7 Table of Contents 4.3 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56 4.4 FLASH Control Register (FLCR) . . . . . . . . . . . . . . . . . . . . . . . 56 4.5 FLASH Block Erase Operation . . . . . . . . . . . . . . . . . . . . . . . . . 57 4.6 FLASH Mass Erase Operation . . . . . . . . . . . . . . . . . . . . . . . . . 58 4.7 FLASH Program Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . .59 4.8 FLASH Block Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 4.9 FLASH Block Protect Register (FLBPR). . . . . . . . . . . . . . . . . . 61 Section 5. Configuration Register (CONFIG) 5.1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .63 5.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 5.3 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .63 5.3.1 Configuration Register 0. . . . . . . . . . . . . . . . . . . . . . . . . . . .64 5.3.2 Configuration Register 1. . . . . . . . . . . . . . . . . . . . . . . . . . . .65 Section 6. Central Processor Unit (CPU) 6.1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .67 6.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 6.3 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 6.4 CPU Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 6.4.1 Accumulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 6.4.2 Index Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 6.4.3 Stack Pointer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 6.4.4 Program Counter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 6.4.5 Condition Code Register . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 6.5 Arithmetic/Logic Unit (ALU) . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 6.6 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 6.6.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .74 6.6.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .75 6.7 CPU During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . 75 Data Sheet 8 MC68HC908BD48 — Rev. 2.0 Table of Contents MOTOROLA Table of Contents 6.8 Instruction Set Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 6.9 Opcode Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 Section 7. System Integration Module (SIM) 7.1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .87 7.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 7.3 SIM Bus Clock Control and Generation . . . . . . . . . . . . . . . . . . 91 7.3.1 Bus Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 7.3.2 Clock Start-Up from POR . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 7.3.3 Clocks in Stop Mode and Wait Mode . . . . . . . . . . . . . . . . . . 91 7.4 Reset and System Initialization. . . . . . . . . . . . . . . . . . . . . . . . . 92 7.4.1 External Pin Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 7.4.2 Active Resets from Internal Sources . . . . . . . . . . . . . . . . . . 93 7.4.2.1 Power-On Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .94 7.4.2.2 Computer Operating Properly (COP) Reset. . . . . . . . . . . 95 7.4.2.3 Illegal Opcode Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96 7.4.2.4 Illegal Address Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . .96 7.5 SIM Counter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96 7.5.1 SIM Counter During Power-On Reset . . . . . . . . . . . . . . . . . 96 7.5.2 SIM Counter During Stop Mode Recovery . . . . . . . . . . . . . . 97 7.5.3 SIM Counter and Reset States. . . . . . . . . . . . . . . . . . . . . . . 97 7.6 Exception Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .97 7.6.1 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98 7.6.1.1 Hardware Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 7.6.1.2 SWI Instruction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101 7.6.2 Interrupt Status Registers. . . . . . . . . . . . . . . . . . . . . . . . . . 101 7.6.2.1 Interrupt Status Register 1 . . . . . . . . . . . . . . . . . . . . . . . 103 7.6.2.2 Interrupt Status Register 2 . . . . . . . . . . . . . . . . . . . . . . . 103 7.6.3 Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104 7.6.4 Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104 7.6.5 Status Flag Protection in Break Mode . . . . . . . . . . . . . . . . 104 7.7 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105 7.7.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .105 7.7.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .106 MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Table of Contents 9 Table of Contents 7.8 SIM Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108 7.8.1 SIM Break Status Register (SBSR) . . . . . . . . . . . . . . . . . . 108 7.8.2 SIM Reset Status Register (SRSR) . . . . . . . . . . . . . . . . . . 109 7.8.3 SIM Break Flag Control Register (SBFCR) . . . . . . . . . . . . 110 Section 8. Oscillator (OSC) 8.1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .111 8.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111 8.3 Oscillator External Connections . . . . . . . . . . . . . . . . . . . . . . .112 8.4 I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113 8.4.1 Crystal Amplifier Input Pin (OSC1). . . . . . . . . . . . . . . . . . . 113 8.4.2 Crystal Amplifier Output Pin (OSC2) . . . . . . . . . . . . . . . . . 113 8.4.3 Oscillator Enable Signal (SIMOSCEN). . . . . . . . . . . . . . . . 113 8.4.4 External Clock Source (OSCXCLK) . . . . . . . . . . . . . . . . . . 113 8.4.5 Oscillator Out (OSCOUT). . . . . . . . . . . . . . . . . . . . . . . . . . 113 8.5 Low Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 8.5.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .114 8.5.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .114 8.6 Oscillator During Break Mode. . . . . . . . . . . . . . . . . . . . . . . . . 114 Section 9. Monitor ROM (MON) 9.1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .115 9.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 9.3 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116 9.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .116 9.4.1 Entering Monitor Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118 9.4.2 Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119 9.4.3 Echoing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120 9.4.4 Break Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120 9.4.5 Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121 9.4.6 Baud Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .124 Data Sheet 10 MC68HC908BD48 — Rev. 2.0 Table of Contents MOTOROLA Table of Contents Section 10. Timer Interface Module (TIM) 10.1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .125 10.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126 10.3 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126 10.4 Pin Name Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126 10.5 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .127 10.5.1 TIM Counter Prescaler . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129 10.5.2 Input Capture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129 10.5.3 Output Compare. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129 10.5.3.1 Unbuffered Output Compare . . . . . . . . . . . . . . . . . . . . . 130 10.5.3.2 Buffered Output Compare . . . . . . . . . . . . . . . . . . . . . . .131 10.5.4 Pulse Width Modulation (PWM) . . . . . . . . . . . . . . . . . . . . . 131 10.5.4.1 Unbuffered PWM Signal Generation . . . . . . . . . . . . . . . 132 10.5.4.2 Buffered PWM Signal Generation . . . . . . . . . . . . . . . . . 133 10.5.4.3 PWM Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134 10.6 Interrupts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .135 10.7 Wait Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135 10.8 TIM During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . 136 10.9 I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136 10.10 I/O Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137 10.10.1 TIM Status and Control Register (TSC) . . . . . . . . . . . . . . . 137 10.10.2 TIM Counter Registers (TCNTH:TCNTL) . . . . . . . . . . . . . . 139 10.10.3 TIM Counter Modulo Registers (TMODH:TMODL) . . . . . . 140 10.10.4 TIM Channel Status and Control Registers (TSC0:TSC1) . 141 10.10.5 TIM Channel Registers (TCH0H/L:TCH1H/L) . . . . . . . . . . 145 Section 11. Pulse Width Modulator (PWM) 11.1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .147 11.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147 11.3 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .147 11.4 PWM Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149 MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Table of Contents 11 Table of Contents 11.4.1 11.4.2 PWM Data Registers 0 to 15 (0PWM–15PWM). . . . . . . . . 150 PWM Control Registers 1 and 2 (PWMCR1:PWMCR2) . . 151 Section 12. Analog-to-Digital Converter (ADC) 12.1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .153 12.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153 12.3 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154 12.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .154 12.4.1 ADC Port I/O Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155 12.4.2 Voltage Conversion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .156 12.4.3 Conversion Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156 12.4.4 Continuous Conversion . . . . . . . . . . . . . . . . . . . . . . . . . . . 156 12.4.5 Accuracy and Precision . . . . . . . . . . . . . . . . . . . . . . . . . . . 157 12.5 Interrupts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .157 12.6 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157 12.6.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .157 12.6.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .157 12.7 I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157 12.7.1 ADC Voltage In (ADCVIN) . . . . . . . . . . . . . . . . . . . . . . . . . 158 12.8 I/O Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158 12.8.1 ADC Status and Control Register. . . . . . . . . . . . . . . . . . . .158 12.8.2 ADC Data Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160 12.8.3 ADC Input Clock Register . . . . . . . . . . . . . . . . . . . . . . . . . 161 Section 13. Universal Serial Bus Module (USB) 13.1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .163 13.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163 13.3 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164 13.4 I/O Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164 13.5 Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .165 13.5.1 USB Address Register (UADR) . . . . . . . . . . . . . . . . . . . . . 166 Data Sheet 12 MC68HC908BD48 — Rev. 2.0 Table of Contents MOTOROLA Table of Contents 13.5.2 13.5.3 13.5.4 13.5.5 13.5.6 13.5.7 13.5.8 13.5.9 USB Interrupt Register (UINTR). . . . . . . . . . . . . . . . . . . . . 166 USB Interrupt Register 1 (UIR1). . . . . . . . . . . . . . . . . . . . . 169 USB Control Register 0 (UCR0). . . . . . . . . . . . . . . . . . . . . 171 USB Control Register 1 (UCR1). . . . . . . . . . . . . . . . . . . . . 172 USB Control Register 2 (UCR2). . . . . . . . . . . . . . . . . . . . . 174 USB Status Register (USR) . . . . . . . . . . . . . . . . . . . . . . . . 175 USB Endpoint 0 Data Registers 0 to 7 (UD0R0–UD0R7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177 USB Endpoint 1/2 Data Registers 0 to 7 (UD1R0–UD1R7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177 Section 14. Multi-Master IIC Interface (MMIIC) 14.1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .179 14.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179 14.3 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180 14.4 I/O Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180 14.5 Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .181 14.5.1 Multi-Master IIC Address Register (MMADR) . . . . . . . . . . 182 14.5.2 Multi-Master IIC Control Register (MMCR) . . . . . . . . . . . . 183 14.5.3 Multi-Master IIC Master Control Register (MIMCR) . . . . . . 184 14.5.4 Multi-Master IIC Status Register (MMSR) . . . . . . . . . . . . . 186 14.5.5 Multi-Master IIC Data Transmit Register (MMDTR) . . . . . . 188 14.5.6 Multi-Master IIC Data Receive Register (MMDRR) . . . . . . 189 14.6 Programming Considerations . . . . . . . . . . . . . . . . . . . . . . . . . 190 Section 15. DDC12AB Interface 15.1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .193 15.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193 15.3 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194 15.4 I/O Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194 15.5 DDC Protocols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196 15.6 Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .196 MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Table of Contents 13 Table of Contents 15.6.1 15.6.2 15.6.3 15.6.4 15.6.5 15.6.6 15.6.7 15.7 DDC Address Register (DADR) . . . . . . . . . . . . . . . . . . . . . 196 DDC2 Address Register (D2ADR) . . . . . . . . . . . . . . . . . . . 197 DDC Control Register (DCR) . . . . . . . . . . . . . . . . . . . . . . . 198 DDC Master Control Register (DMCR) . . . . . . . . . . . . . . . 199 DDC Status Register (DSR) . . . . . . . . . . . . . . . . . . . . . . . . 202 DDC Data Transmit Register (DDTR) . . . . . . . . . . . . . . . . 204 DDC Data Receive Register (DDRR) . . . . . . . . . . . . . . . . . 205 Programming Considerations . . . . . . . . . . . . . . . . . . . . . . . . . 206 Section 16. Sync Processor 16.1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .209 16.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209 16.3 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211 16.4 I/O Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211 16.5 Functional Blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213 16.5.1 Polarity Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214 16.5.1.1 Hsync Polarity Detection . . . . . . . . . . . . . . . . . . . . . . . . 214 16.5.1.2 Vsync Polarity Detection . . . . . . . . . . . . . . . . . . . . . . . . 214 16.5.1.3 Composite Sync Polarity Detection . . . . . . . . . . . . . . . . 214 16.5.2 Sync Signal Counters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215 16.5.3 Polarity Controlled HSYNCO and VSYNCO Outputs. . . . . 215 16.5.4 Clamp Pulse Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216 16.5.5 Low Vertical Frequency Detect . . . . . . . . . . . . . . . . . . . . . 217 16.6 Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .217 16.6.1 Sync Processor Control & Status Register (SPCSR). . . . . 217 16.6.2 Sync Processor Input/Output Control Register (SPIOCR) . 219 16.6.3 Vertical Frequency Registers (VFRs). . . . . . . . . . . . . . . . . 221 16.6.4 Hsync Frequency Registers (HFRs). . . . . . . . . . . . . . . . . . 223 16.6.5 Sync Processor Control Register 1 (SPCR1). . . . . . . . . . . 225 16.6.6 H&V Sync Output Control Register (HVOCR) . . . . . . . . . . 226 16.7 System Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .227 Data Sheet 14 MC68HC908BD48 — Rev. 2.0 Table of Contents MOTOROLA Table of Contents Section 17. Input/Output (I/O) Ports 17.1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .229 17.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229 17.3 Port A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233 17.3.1 Port A Data Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233 17.3.2 Data Direction Register A . . . . . . . . . . . . . . . . . . . . . . . . . 234 17.3.3 Port A Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235 17.4 Port B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236 17.4.1 Port B Data Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236 17.4.2 Data Direction Register B . . . . . . . . . . . . . . . . . . . . . . . . . 237 17.4.3 Port B Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238 17.5 Port C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239 17.5.1 Port C Data Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239 17.5.2 Data Direction Register C . . . . . . . . . . . . . . . . . . . . . . . . . 240 17.5.3 Port C Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241 17.6 Port D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242 17.6.1 Port D Data Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242 17.6.2 Data Direction Register D. . . . . . . . . . . . . . . . . . . . . . . . . . 243 17.6.3 Port D Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245 17.7 Port E . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247 17.7.1 Port E Data Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247 17.7.2 Data Direction Register E. . . . . . . . . . . . . . . . . . . . . . . . . . 248 17.7.3 Port E Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250 Section 18. External Interrupt (IRQ) 18.1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .251 18.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251 18.3 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251 18.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .252 18.5 IRQ Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 254 18.6 IRQ Module During Break Interrupts . . . . . . . . . . . . . . . . . . . 255 18.7 IRQ Status and Control Register . . . . . . . . . . . . . . . . . . . . . . 255 MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Table of Contents 15 Table of Contents Section 19. Computer Operating Properly (COP) 19.1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .257 19.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257 19.3 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .258 19.4 I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259 19.4.1 OSCXCLK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .259 19.4.2 STOP Instruction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259 19.4.3 COPCTL Write . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .259 19.4.4 Power-On Reset. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259 19.4.5 Internal Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260 19.4.6 Reset Vector Fetch. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260 19.4.7 COPD (COP Disable). . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260 19.4.8 COPRS (COP Rate Select) . . . . . . . . . . . . . . . . . . . . . . . . 260 19.5 COP Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261 19.6 Interrupts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .261 19.7 Monitor Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .261 19.8 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261 19.8.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .262 19.8.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .262 19.9 COP Module During Break Mode . . . . . . . . . . . . . . . . . . . . . . 262 Section 20. Break Module (BRK) 20.1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .263 20.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263 20.3 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264 20.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .264 20.4.1 Flag Protection During Break Interrupts . . . . . . . . . . . . . . . 266 20.4.2 CPU During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . .266 20.4.3 TIM During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . 266 20.4.4 COP During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . 266 20.5 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266 Data Sheet 16 MC68HC908BD48 — Rev. 2.0 Table of Contents MOTOROLA Table of Contents 20.5.1 20.5.2 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .266 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .267 20.6 Break Module Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267 20.6.1 Break Status and Control Register. . . . . . . . . . . . . . . . . . . 267 20.6.2 Break Address Registers . . . . . . . . . . . . . . . . . . . . . . . . . . 268 20.6.3 SIM Break Status Register . . . . . . . . . . . . . . . . . . . . . . . . . 268 20.6.4 SIM Break Flag Control Register . . . . . . . . . . . . . . . . . . . . 270 Section 21. Electrical Specifications 21.1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .271 21.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271 21.3 Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . 272 21.4 Functional Operating Range. . . . . . . . . . . . . . . . . . . . . . . . . . 273 21.5 Thermal Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273 21.6 DC Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . 274 21.7 Control Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275 21.8 Oscillator Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275 21.9 ADC Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276 21.10 USB DC Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . 277 21.11 USB Low Speed Source Electrical Characteristics. . . . . . . . . 278 21.12 Timer Interface Module Characteristics . . . . . . . . . . . . . . . . . 278 21.13 DDC12AB/MMIIC Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . 279 21.13.1 DDC12AB/MMIIC Interface Input Signal Timing . . . . . . . . 279 21.13.2 DDC12AB/MMIIC Interface Output Signal Timing . . . . . . . 279 21.14 Sync Processor Timing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 280 21.15 Memory Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 281 MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Table of Contents 17 Table of Contents Section 22. Mechanical Specifications 22.1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .283 22.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283 22.4 42-Pin Shrink Dual in-Line Package (SDIP) . . . . . . . . . . . . . . 283 22.5 44-Pin Plastic Quad Flat Pack (QFP) . . . . . . . . . . . . . . . . . . . 284 Section 23. Ordering Information 23.1 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .285 23.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 285 23.3 MC Order Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 285 Data Sheet 18 MC68HC908BD48 — Rev. 2.0 Table of Contents MOTOROLA Data Sheet – MC68HC908BD48 List of Figures Figure Title 1-1 1-2 1-3 MCU Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 44-Pin QFP Pin Assignments . . . . . . . . . . . . . . . . . . . . . . . . . . 29 42-Pin SDIP Pin Assignments . . . . . . . . . . . . . . . . . . . . . . . . . 30 2-1 2-2 Memory Map. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 Control, Status, and Data Registers . . . . . . . . . . . . . . . . . . . . .39 4-1 4-2 4-3 4-4 FLASH Control Register (FLCR) . . . . . . . . . . . . . . . . . . . . . . . 56 FLASH Programming Flowchart . . . . . . . . . . . . . . . . . . . . . . . . 60 FLASH Block Protect Register (FLBPR). . . . . . . . . . . . . . . . . . 61 FLASH Block Protect Start Address . . . . . . . . . . . . . . . . . . . . .62 5-1 5-2 Configuration Register 0 (CONFIG0) . . . . . . . . . . . . . . . . . . . . 64 Configuration Register 1 (CONFIG1) . . . . . . . . . . . . . . . . . . . . 65 6-1 6-2 6-3 6-4 6-5 6-6 CPU Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 Accumulator (A) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 Index Register (H:X) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 Stack Pointer (SP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 Program Counter (PC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .71 Condition Code Register (CCR) . . . . . . . . . . . . . . . . . . . . . . . . 72 7-1 7-2 7-3 7-4 7-5 7-6 7-7 7-8 7-9 7-10 SIM Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 OSC Clock Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 External Reset Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .93 Internal Reset Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 Sources of Internal Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94 POR Recovery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 Interrupt Entry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98 Interrupt Recovery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98 Interrupt Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99 Interrupt Recognition Example . . . . . . . . . . . . . . . . . . . . . . . . 100 MC68HC908BD48 — Rev. 2.0 MOTOROLA Page Data Sheet List of Figures 19 List of Figures Figure Title Page 7-11 7-12 7-13 7-14 7-15 7-16 7-17 7-18 7-19 7-20 Interrupt Status Register 1 (INT1). . . . . . . . . . . . . . . . . . . . . . 103 Interrupt Status Register 2 (INT2). . . . . . . . . . . . . . . . . . . . . . 103 Wait Mode Entry Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105 Wait Recovery from Interrupt or Break . . . . . . . . . . . . . . . . . . 106 Wait Recovery from Internal Reset. . . . . . . . . . . . . . . . . . . . . 106 Stop Mode Entry Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 Stop Mode Recovery from Interrupt or Break . . . . . . . . . . . . . 107 SIM Break Status Register (SBSR) . . . . . . . . . . . . . . . . . . . . 108 SIM Reset Status Register (SRSR) . . . . . . . . . . . . . . . . . . . . 109 SIM Break Flag Control Register (SBFCR) . . . . . . . . . . . . . . 110 8-1 Oscillator External Connections . . . . . . . . . . . . . . . . . . . . . . .112 9-1 9-2 9-3 9-4 9-5 Monitor Mode Circuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117 Monitor Data Format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119 Sample Monitor Waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . 119 Read Transaction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .120 Break Transaction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .120 10-1 10-2 10-3 10-4 10-5 10-6 10-7 10-8 TIM Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 PWM Period and Pulse Width . . . . . . . . . . . . . . . . . . . . . . . . 132 TIM Status and Control Register (TSC) . . . . . . . . . . . . . . . . . 137 TIM Counter Registers (TCNTH:TCNTL) . . . . . . . . . . . . . . . . 140 TIM Counter Modulo Registers (TMODH:TMODL). . . . . . . . . 141 TIM Channel Status and Control Registers (TSC0:TSC1) . . . 142 CHxMAX Latency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .145 TIM Channel Registers (TCH0H/L:TCH1H/L). . . . . . . . . . . . . 146 11-1 PWM Data Registers 0 to 15 (0PWM–15PWM) . . . . . . . . . . . 150 11-2 PWM Control Register 1 and 2 (PWMCR1:PWMCR2). . . . . . 151 11-3 8-Bit PWM Output Waveforms . . . . . . . . . . . . . . . . . . . . . . . . 152 12-1 12-2 12-3 12-4 ADC Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155 ADC Status and Control Register (ADSCR) . . . . . . . . . . . . . . 158 ADC Data Register (ADR) . . . . . . . . . . . . . . . . . . . . . . . . . . . 160 ADC Input Clock Register (ADICLK) . . . . . . . . . . . . . . . . . . . 161 13-1 USB Address Register (UADR) . . . . . . . . . . . . . . . . . . . . . . .166 13-2 USB Interrupt Register (UINTR) . . . . . . . . . . . . . . . . . . . . . . . 166 Data Sheet 20 MC68HC908BD48 — Rev. 2.0 List of Figures MOTOROLA List of Figures Figure Title 13-3 13-4 13-5 13-6 13-7 13-8 13-9 USB Interrupt Register 1 (UIR1) . . . . . . . . . . . . . . . . . . . . . . . 169 USB Control Register 0 (UCR0) . . . . . . . . . . . . . . . . . . . . . . . 171 USB Control Register 1 (UCR1) . . . . . . . . . . . . . . . . . . . . . . . 172 USB Control Register 2 (UCR2) . . . . . . . . . . . . . . . . . . . . . . . 174 USB Status Register (USR) . . . . . . . . . . . . . . . . . . . . . . . . . . 175 USB Endpoint 0 Data Registers 0 to 7 (UD0R0–UD0R7) . . . 177 USB Endpoint 1 Data Registers 0 to 7 (UD1R0–UD1R7) . . . 177 14-1 14-2 14-3 14-4 14-5 14-6 14-7 Multi-Master IIC Address Register (MMADR). . . . . . . . . . . . . 182 Multi-Master IIC Control Register (MMCR). . . . . . . . . . . . . . . 183 Multi-Master IIC Master Control Register (MIMCR) . . . . . . . . 184 Multi-Master IIC Status Register (MMSR) . . . . . . . . . . . . . . . 186 Multi-Master IIC Data Transmit Register (MMDTR) . . . . . . . . 188 Multi-Master IIC Data Receive Register (MMDRR) . . . . . . . . 189 Data Transfer Sequences for Master/Slave Transmit/Receive Modes . . . . . . . . . . . . . . . . . . . . . . . . . . 191 15-1 15-2 15-3 15-4 15-5 15-6 15-7 15-8 DDC Address Register (DADR) . . . . . . . . . . . . . . . . . . . . . . .196 DDC2 Address Register (D2ADR) . . . . . . . . . . . . . . . . . . . . . 197 DDC Control Register (DCR) . . . . . . . . . . . . . . . . . . . . . . . . . 198 DDC Master Control Register (DMCR). . . . . . . . . . . . . . . . . . 199 DDC Status Register (DSR) . . . . . . . . . . . . . . . . . . . . . . . . . . 202 DDC Data Transmit Register (DDTR). . . . . . . . . . . . . . . . . . . 204 DDC Data Receive Register (DDRR) . . . . . . . . . . . . . . . . . . . 205 Data Transfer Sequences for Master/Slave Transmit/Receive Modes . . . . . . . . . . . . . . . . . . . . . . . . . . 207 16-1 16-2 16-3 16-4 16-5 16-6 16-7 16-8 16-9 16-10 Sync Processor Block Diagram . . . . . . . . . . . . . . . . . . . . . . .213 Clamp Pulse Output Timing . . . . . . . . . . . . . . . . . . . . . . . . . . 216 Sync Processor Control & Status Register (SPCSR) . . . . . . . 217 Sync Processor Input/Output Control Register (SPIOCR) . . . 219 Vertical Frequency High Register . . . . . . . . . . . . . . . . . . . . . . 221 Vertical Frequency Low Register . . . . . . . . . . . . . . . . . . . . . . 221 Hsync Frequency High Register . . . . . . . . . . . . . . . . . . . . . . . 223 Hsync Frequency Low Register . . . . . . . . . . . . . . . . . . . . . . .223 Sync Processor Control Register 1 (SPCR1) . . . . . . . . . . . . . 225 H&V Sync Output Control Register (HVOCR) . . . . . . . . . . . . 226 MC68HC908BD48 — Rev. 2.0 MOTOROLA Page Data Sheet List of Figures 21 List of Figures Figure 17-1 17-2 17-3 17-4 17-5 17-6 17-7 17-8 17-9 17-10 17-11 17-12 17-13 17-14 17-15 17-16 17-17 17-18 17-19 Title Page Port A Data Register (PTA) . . . . . . . . . . . . . . . . . . . . . . . . . . 233 Data Direction Register A (DDRA) . . . . . . . . . . . . . . . . . . . . . 234 Port A I/O Circuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 234 PWM Control Register 1 (PWMCR1) . . . . . . . . . . . . . . . . . . . 235 Port B Data Register (PTB) . . . . . . . . . . . . . . . . . . . . . . . . . . 236 Data Direction Register B (DDRB) . . . . . . . . . . . . . . . . . . . . . 237 Port B I/O Circuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237 PWM Control Register 1 (PWMCR1) . . . . . . . . . . . . . . . . . . . 238 Port C Data Register (PTC) . . . . . . . . . . . . . . . . . . . . . . . . . . 239 Data Direction Register C (DDRC) . . . . . . . . . . . . . . . . . . . . . 240 Port C I/O Circuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241 Port D Data Register (PTD) . . . . . . . . . . . . . . . . . . . . . . . . . . 242 Data Direction Register D (DDRD) . . . . . . . . . . . . . . . . . . . . . 243 Port D I/O Circuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244 Port D Configuration Register (PDCR) . . . . . . . . . . . . . . . . . . 245 Port E Data Register (PTE) . . . . . . . . . . . . . . . . . . . . . . . . . . 247 Data Direction Register E (DDRE) . . . . . . . . . . . . . . . . . . . . . 248 Port E I/O Circuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249 Configuration Register 0 (CONFIG0) . . . . . . . . . . . . . . . . . . . 250 18-1 IRQ Module Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . 253 18-2 IRQ Status and Control Register (INTSCR) . . . . . . . . . . . . . . 256 19-1 COP Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 258 19-2 Configuration Register 1 (CONFIG1) . . . . . . . . . . . . . . . . . . . 260 19-3 COP Control Register (COPCTL) . . . . . . . . . . . . . . . . . . . . . . 261 20-1 20-2 20-3 20-4 20-5 20-6 Break Module Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . 265 Break Status and Control Register (BRKSCR). . . . . . . . . . . . 267 Break Address Register High (BRKH) . . . . . . . . . . . . . . . . . . 268 Break Address Register Low (BRKL) . . . . . . . . . . . . . . . . . . . 268 SIM Break Status Register (SBSR) . . . . . . . . . . . . . . . . . . . . 269 SIM Break Flag Control Register (SBFCR) . . . . . . . . . . . . . . 270 21-1 ADC Input Voltage vs. Step Readings . . . . . . . . . . . . . . . . . . 277 22-2 42-Pin SDIP (Case #858) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283 22-3 44-Pin QFP (Case #824A) . . . . . . . . . . . . . . . . . . . . . . . . . . . 284 Data Sheet 22 MC68HC908BD48 — Rev. 2.0 List of Figures MOTOROLA Data Sheet – MC68HC908BD48 List of Tables Table Title Page 1-1 Pin Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31 2-1 Vector Addresses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51 6-1 6-2 Instruction Set Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 Opcode Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 7-1 7-2 7-3 7-4 7-5 SIM I/O Register Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . .90 Signal Name Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 PIN Bit Set Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 Interrupt Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102 SIM Registers Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108 9-1 9-2 9-3 9-4 9-5 9-6 9-7 9-8 9-9 Mode Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118 Mode Differences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119 READ (Read Memory) Command . . . . . . . . . . . . . . . . . . . . . 121 WRITE (Write Memory) Command. . . . . . . . . . . . . . . . . . . . . 122 IREAD (Indexed Read) Command . . . . . . . . . . . . . . . . . . . . . 122 IWRITE (Indexed Write) Command . . . . . . . . . . . . . . . . . . . . 123 READSP (Read Stack Pointer) Command . . . . . . . . . . . . . . . 123 RUN (Run User Program) Command . . . . . . . . . . . . . . . . . . . 124 Monitor Baud Rate Selection . . . . . . . . . . . . . . . . . . . . . . . . . 124 10-1 10-2 10-3 10-4 Pin Name Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126 TIM I/O Register Summary . . . . . . . . . . . . . . . . . . . . . . . . . . .128 Prescaler Selection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139 Mode, Edge, and Level Selection . . . . . . . . . . . . . . . . . . . . . . 144 11-1 PWM I/O Register Summary . . . . . . . . . . . . . . . . . . . . . . . . . 148 11-2 PWM Channels and Port I/O pins. . . . . . . . . . . . . . . . . . . . . . 151 MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet List of Tables 23 List of Tables Table Title Page 12-1 ADC Register Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154 12-2 MUX Channel Select . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160 12-3 ADC Clock Divide Ratio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161 13-1 Pin Name Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164 13-2 USB I/O Register Summary . . . . . . . . . . . . . . . . . . . . . . . . . . 165 14-1 Pin Name Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180 14-2 MMIIC I/O Register Summary. . . . . . . . . . . . . . . . . . . . . . . . . 181 14-3 Baud Rate Select . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186 15-1 Pin Name Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194 15-2 DDC I/O Register Summary . . . . . . . . . . . . . . . . . . . . . . . . . . 195 15-3 Baud Rate Select . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201 16-1 16-2 16-3 16-4 16-5 16-6 16-7 16-8 16-9 16-10 Pin Name Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211 Sync Processor I/O Register Summary . . . . . . . . . . . . . . . . . 212 Sync Output Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215 Sync Output Polarity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216 ATPOL, VINVO, and HINVO setting. . . . . . . . . . . . . . . . . . . .219 Sample Vertical Frame Frequencies . . . . . . . . . . . . . . . . . . . 222 Clamp Pulse Width . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223 HSYNC Polarity Detection Pulse Width . . . . . . . . . . . . . . . . . 225 ATPOL, VINVO, and HINVO setting. . . . . . . . . . . . . . . . . . . .226 Free-Running HSYNC and VSYNC Options . . . . . . . . . . . . . 227 17-1 17-2 17-3 17-4 17-5 17-6 17-7 I/O Port Register Summary. . . . . . . . . . . . . . . . . . . . . . . . . . .230 Port Control Register Bits Summary. . . . . . . . . . . . . . . . . . . .232 Port A Pin Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235 Port B Pin Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238 Port C Pin Functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241 Port D Pin Functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244 Port E Pin Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249 18-1 IRQ I/O Register Summary. . . . . . . . . . . . . . . . . . . . . . . . . . .253 20-1 Break Module I/O Register Summary . . . . . . . . . . . . . . . . . . . 265 23-1 MC Order Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 285 Data Sheet 24 MC68HC908BD48 — Rev. 2.0 List of Tables MOTOROLA Data Sheet – MC68HC908BD48 Section 1. General Description 1.1 Contents 1.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 1.3 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 1.4 MCU Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 1.5 Pin Assignments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 1.6 Pin Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31 1.2 Introduction The MC68HC908BD48 is a member of the low-cost, high-performance M68HC08 Family of 8-bit microcontroller units (MCUs). The M68HC08 Family is based on the customer-specified integrated circuit (CSIC) design strategy. 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. With special modules such as the sync processor, analog-to-digital converter, pulse modulator module, DDC12AB interface, multi-master IIC interface, and universal serial bus interface, the MC68HC908BD48 is designed specifically for use in digital monitor systems. 1.3 Features Features of the MC68HC908BD48 MCU include the following: • High-performance M68HC08 architecture • Fully upward-compatible object code with M6805, M146805, and M68HC05 families MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet General Description 25 General Description • Low-power design; fully static with stop and wait modes • 5V operating voltage • 6MHz internal bus frequency; with 24MHz external crystal • 48,128 bytes of on-chip FLASH memory • 1,024 bytes of on-chip random access memory (RAM) • Sync signal processor with the following features: – Horizontal and vertical frequency counters – Low vertical frequency indicator (40.7Hz) – Polarity controlled Hsync and Vsync outputs from separate sync or composite sync inputs – Internal generated free-running Hsync and Vsync pulses – CLAMP pulse output to the external pre-amp chip • 6-channel, 8-bit analog-to-digital converter (ADC) • 16-channel, 8-bit pulse width modulator (PWM) • Full universal serial bus (USB) specification 1.0 compliant lowspeed bus with 3 endpoints: – 1 Control endpoint (two 8-byte buffer) – 2 Interrupt endpoints (one 8-byte buffer shared) • On-chip 3.3V regulator for USB pull-up resistor • DDC12AB1 module with the following: – DDC1 hardware – Multi-master IIC2 hardware for DDC2AB; with dual address • Additional multi-master IIC module • 16-bit, 2-channel timer interface modules (TIM) with selectable input capture, output compare, and PWM capability on one channel • 32 general purpose input/output (I/O) pins, including: – 4 open-drain pins 1. DDC is a VESA bus standard. 2. IIC is a proprietary Philips interface bus. Data Sheet 26 MC68HC908BD48 — Rev. 2.0 General Description MOTOROLA General Description MCU Block Diagram • System protection features: – Optional computer operating properly (COP) reset – Illegal opcode detection with reset – Illegal address detection with reset • FLASH memory security1 • Master reset pin with internal pull-up and power-on reset • IRQ with programmable pull-up and schmitt-trigger input • 42-pin SDIP and 44-pin QFP packages 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 • Third party C language support 1.4 MCU Block Diagram Figure 1-1 shows the structure of the MC68HC908BD48. 1. No security feature is absolutely secure. However, Motorola’s strategy is to make reading or copying the FLASH difficult for unauthorized users. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet General Description 27 DDRA PORTA PTA7/PWM15–PTA0/PWM8 PORTB PTB7/PWM7–PTB0/PWM0 PORTC PULSE WIDTH MODULATOR MODULE DDRB ARITHMETIC/LOGIC UNIT (ALU) DDRC CPU REGISTERS PTC5/ADC5–PTC0/ADC0 CONTROL AND STATUS REGISTERS — 80 BYTES 8-BIT ANALOG-TO-DIGITAL CONVERTER MODULE USER FLASH — 48,128 BYTES MULTI-MASTER IIC INTERFACE MODULE USER RAM — 1024 BYTES MONITOR ROM — 512+470 BYTES DDC12AB INTERFACE MODULE USER FLASH VECTOR SPACE — 26 BYTES General Description ‡ OSC1 UNIVERSAL SERIAL BUS INTERFACE MODULE OSCILLATOR ‡ OSC2 ÷2 HSYNC VSYNC EXTERNAL IRQ MODULE PORTD IRQ 2-CHANNEL TIMER INTERFACE MODULE PTD6/IICSDA † PTD5/IICSCL † PTD4/CLAMP PTD3/DDCSCL † PTD2/DDCSDA † PTD1/D– ‡ PTD0/D+ ‡ PORTE RST SYSTEM INTEGRATION MODULE DDRD SYNC PROCESSOR MODULE PTE2/VSYNCO PTE1/HSYNCO PTE0/SOG/TCH0 MONITOR MODULE MOTOROLA MC68HC908BD48 — Rev. 2.0 POWER-ON RESET MODULE VDD VSS VDD3 VSS1 POWER SECURITY MODULE MONITOR MODE ENTRY MODULE USB VOLTAGE REGULATOR Figure 1-1. MCU Block Diagram DDRE COMPUTER OPERATING PROPERLY MODULE † Pin is +5V open-drain ‡ Pin is +3.3V General Description Data Sheet 28 INTERNAL BUS M68HC08 CPU General Description Pin Assignments PD0/D+ PD1/D– VDD3 VSYNC HSYNC PTC0/ADC0 PTC1/ADC1 PTC2/ADC2 42 41 40 39 38 37 36 35 34 PTC3/ADC3 NC OSC2 1 43 44 VDD 1.5 Pin Assignments 33 PTE2/VSYNCO 28 PTB3/PWM3 PTB5/PWM5 7 27 PTB4/PWM4 PTC5/ADC5 8 26 VSS1 PTC4/ADC4 9 25 NC 10 24 PTD2/DDCSDA PTA7/PWM15 12 PTE0/SOG/TCH0 11 23 PTD3/DDCSCL PTD4/CLAMP 22 IRQ 21 6 PTD5/IICSCL PTB6/PWM6 20 PTB2/PWM2 PTD6/IICSDA 29 19 5 PTA0/PWM8 PTB7/PWM7 18 PTB1/PWM1 PTA1/PWM9 30 17 4 PTA2/PWM10 RST 16 PTB0/PWM0 PTA3/PWM11 31 15 3 PTA4/PWM12 VSS 14 PTE1/HSYNCO PTA5/PWM13 32 13 2 PTA6/PWM14 OSC1 Figure 1-2. 44-Pin QFP Pin Assignments MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet General Description 29 General Description VSYNC 1 42 HSYNC VDD3 2 41 PTC0/ADC0 PD1/D– 3 40 PTC1/ADC1 PD0/D+ 4 39 PTC2/ADC2 VDD 5 38 PTC3/ADC3 OSC2 6 37 PTE2/VSYNCO OSC1 7 36 PTE1/HSYNCO VSS 8 35 PTB0/PWM0 RST 9 34 PTB1/PWM1 PTB7/PWM7 10 33 PTB2/PWM2 PTB6/PWM6 11 32 PTB3/PWM3 PTB5/PWM5 12 31 PTB4/PWM4 PTC5/ADC5 13 30 VSS1 PTC4/ADC4 14 29 PTD2/DDCSDA IRQ 15 28 PTD3/DDCSCL PTE0/SOG/TCH0 16 27 PTD4/CLAMP PTA7/PWM15 17 26 PTD5/IICSCL PTA6/PWM14 18 25 PTD6/IICSDA PTA5/PWM13 19 24 PTA0/PWM8 PTA4/PWM12 20 23 PTA1/PWM9 PTA3/PWM11 21 22 PTA2/PWM10 Figure 1-3. 42-Pin SDIP Pin Assignments Data Sheet 30 MC68HC908BD48 — Rev. 2.0 General Description MOTOROLA General Description Pin Functions 1.6 Pin Functions Description of the pin functions are provided in Table 1-1. Table 1-1. Pin Functions PIN NAME PIN DESCRIPTION VDD Power supply input to the MCU. VSS Power supply ground. VDD3 3.3V regulated output from the MCU. VSS1 Power supply ground. OSC1 OSC2 Connections to the on-chip oscillator. An external clock can be connected directly to OSC1; with OSC2 floating. These are 3.3V pins. See Section 8. Oscillator (OSC). RST A logic 0 on the RST pin forces the MCU to a known startup state. RST is bidirectional, allowing a reset of the entire system. It is driven low when any internal reset source is asserted. This pin contains an internal pullup resistor. See Section 7. System Integration Module (SIM). IRQ External IRQ pin; with software programmable internal pull-up and schmitt trigger input. This pin is also used for mode entry selection. See Section 7. System Integration Module (SIM). VSYNC Vsync input to the sync processor. See Section 16. Sync Processor. HSYNC Hsync input to the sync processor. See Section 16. Sync Processor. PTA7/PWM15–PTA0/PWM8 These are shared-function pins. Each pin can be configured as a standard I/O pin or a PWM output channel. See Section 17. Input/Output (I/O) Ports and Section 11. Pulse Width Modulator (PWM). PTB7/PWM7–PTB0/PWM0 These are shared-function pins. Each pin can be configured as a standard I/O pin or a PWM output channel. See Section 17. Input/Output (I/O) Ports and Section 11. Pulse Width Modulator (PWM). MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet General Description 31 General Description Table 1-1. Pin Functions PIN NAME PIN DESCRIPTION PTC5/ADC5–PTC0/ADC0 These are shared-function pins. Each pin can be configured as a standard I/O pin or an ADC input channel. See Section 17. Input/Output (I/O) Ports and Section 12. Analog-to-Digital Converter (ADC). PTD6/IICSDA This is a shared function pin. It can be configured as a standard I/O pin or the data line of the multimaster IIC module. This pin is open-drain when configured as output. See Section 17. Input/Output (I/O) Ports and Section 14. Multi-Master IIC Interface (MMIIC). PTD5/IICSCL This is a shared function pin. It can be configured as a standard I/O pin or the clock line of the multimaster IIC module. This pin is open-drain when configured as output. See Section 17. Input/Output (I/O) Ports and Section 14. Multi-Master IIC Interface (MMIIC). PTD4/CLAMP This is a shared function pin. It can be configured as a standard I/O pin or the clamp output from the sync processor. See Section 17. Input/Output (I/O) Ports and Section 16. Sync Processor. PTD3/DDCSCL This is a shared function pin. It can be configured as a standard I/O pin or as the clock line of the DDC12AB module. This pin is open-drain when configured as output. See Section 17. Input/Output (I/O) Ports and Section 15. DDC12AB Interface. PTD2/DDCSDA This is a shared function pin. It can be configured as a standard I/O pin or the data line of the DDC12AB module. This pin is open-drain when configured as output. See Section 17. Input/Output (I/O) Ports and Section 15. DDC12AB Interface. PTD1/D– PTD0/D+ These are 3.3V, shared function pins. The pins can be configured as standard I/O pins or USB interface differential data lines. See Section 17. Input/Output (I/O) Ports and Section 13. Universal Serial Bus Module (USB). Data Sheet 32 MC68HC908BD48 — Rev. 2.0 General Description MOTOROLA General Description Pin Functions Table 1-1. Pin Functions NOTE: PIN NAME PIN DESCRIPTION PTE2/VSYNCO This is a shared function pin. It can be configured as a standard I/O pin or the Hsync output from the sync processor. See Section 17. Input/Output (I/O) Ports and Section 16. Sync Processor. PTE1/HSYNCO This is a shared function pin. It can be configured as a standard I/O pin or the Vsync output from the sync processor. See Section 17. Input/Output (I/O) Ports and Section 16. Sync Processor. PTE0/SOG/TCH0 This is a shared function pin. It can be configured as a standard I/O pin, the SOG input to the sync processor, or the timer channel 0 I/O pin. See Section 17. Input/Output (I/O) Ports, Section 16. Sync Processor, and Section 10. Timer Interface Module (TIM). Any unused inputs and I/O ports should be tied to an appropriate logic level (either VDD or VSS). Although the I/O ports of the MC68HC908BD48 do not require termination, termination is recommended to reduce the possibility of static damage. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet General Description 33 General Description Data Sheet 34 MC68HC908BD48 — Rev. 2.0 General Description MOTOROLA Data Sheet – MC68HC908BD48 Section 2. Memory Map 2.1 Contents 2.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 2.3 Unimplemented Memory Locations . . . . . . . . . . . . . . . . . . . . . 35 2.4 Reserved Memory Locations . . . . . . . . . . . . . . . . . . . . . . . . . . 36 2.5 Input/Output (I/O) Section. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 2.2 Introduction The CPU08 can address 64 Kbytes of memory space. The memory map, shown in Figure 2-1, includes: • 48,128 bytes of FLASH memory • 1,024 bytes of random-access memory (RAM) • 26 bytes of user-defined vectors • 512 + 470 bytes of monitor ROM 2.3 Unimplemented Memory Locations Accessing an unimplemented location can cause an illegal address reset if illegal address resets are enabled. In the memory map (Figure 2-1) and in register figures in this document, unimplemented locations are shaded. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Memory Map 35 Memory Map 2.4 Reserved Memory Locations Accessing a reserved location can have unpredictable effects on MCU operation. In the Figure 2-1 and in register figures in this document, reserved locations are marked with the word Reserved or with the letter R. 2.5 Input/Output (I/O) Section Most of the control, status, and data registers are in the zero page area of $0000–$005F. Additional I/O registers have these addresses: • $FE00; SIM Break Status Register, SBSR • $FE01; SIM Reset Status Register, SRSR • $FE02; reserved • $FE03; SIM Break Flag Control Register, SBFCR • $FE04; Interrupt Status Register 1, INT1 • $FE05; Interrupt Status Register 2, INT2 • $FE06; reserved • $FE07; FLASH Control Register, FLCR • $FE08; FLASH block protect register, FLBPR • $FE09; reserved • $FE0A; reserved • $FE0B; reserved • $FE0C; Break Address Register High, BRKH • $FE0D; Break Address Register Low, BRKL • $FE0E; Break Status and Control Register, BRKSCR Data registers are shown in Figure 2-2. Table 2-1 is a list of vector locations. Data Sheet 36 MC68HC908BD48 — Rev. 2.0 Memory Map MOTOROLA Memory Map Input/Output (I/O) Section $0000 I/O Registers 96 Bytes ↓ $005F $0060 Unimplemented 32 Bytes ↓ $007F $0080 RAM 1,024 Bytes ↓ $047F $0480 Unimplemented 1,920 Bytes ↓ $0BFF $0C00 Reserved 256 Bytes ↓ $0CFF $0D00 Unimplemented 13,056 Bytes ↓ $3FFF $4000 FLASH Memory 48,128 Bytes ↓ $FBFF $FC00 Monitor ROM 512 Bytes ↓ $FDFF $FE00 SIM Break Status Register (SBSR) $FE01 SIM Reset Status Register (SRSR) $FE02 Reserved $FE03 SIM Break Flag Control Register (SBFCR) $FE04 Interrupt Status Register 1 (INT1) Figure 2-1. Memory Map MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Memory Map 37 Memory Map $FE05 Interrupt Status Register 2 (INT2) $FE06 Reserved $FE07 FLASH Control Register (FLCR) $FE08 FLASH Block Protect Register (FLBPR) $FE09 Reserved $FE0A Reserved $FE0B Reserved $FE0C Break Address Register High (BRKH) $FE0D Break Address Register Low (BRKL) $FE0E Break Status and Control Register (BRKSCR) $FE0F Reserved $FE10 ↓ Monitor ROM 470 Bytes $FFE5 $FFE6 ↓ FLASH Vectors 26 Bytes $FFFF Figure 2-1. Memory Map (Continued) Data Sheet 38 MC68HC908BD48 — Rev. 2.0 Memory Map MOTOROLA Memory Map Input/Output (I/O) Section Addr. Register Name $0000 Read: Port A Data Register Write: (PTA) Reset: $0001 $0002 $0003 Read: Port B Data Register Write: (PTB) 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 Read: Port C Data Register Write: (PTC) Reset: 0 Read: Port D Data Register Write: (PTD) Reset: 0 0 PTC5 PTC4 PTC3 Unaffected by reset PTD6 PTD5 PTD4 PTD3 Unaffected by reset Read: DDRA7 Data Direction Register A $0004 Write: (DDRA) Reset: 0 Read: DDRB7 Data Direction Register B $0005 Write: (DDRB) 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 DDRC5 DDRC4 DDRC3 DDRC2 DDRC1 DDRC0 Read: Data Direction Register C $0006 Write: (DDRC) Reset: 0 0 0 0 0 0 0 0 0 0 Read: Data Direction Register D $0007 Write: (DDRD) Reset: 0 DDRD6 DDRD5 DDRD4 DDRD3 DDRD2 DDRD1 DDRD0 0 0 0 0 0 0 0 0 Read: Port E Data Register Write: (PTE) Reset: 0 0 0 0 0 PTE2 PTE1 PTE0 Read: Data Direction Register E $0009 Write: (DDRE) Reset: 0 0 0 0 0 DDRE2 DDRE1 DDRE0 0 0 0 0 0 0 0 0 $0008 Unaffected by reset = Unimplemented R = Reserved Figure 2-2. Control, Status, and Data Registers (Sheet 1 of 12) MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Memory Map 39 Memory Map Addr. 6 5 TOIE TSTOP 0 0 1 0 0 0 0 Read: TIM Counter Register High Write: (TCNTH) Reset: Bit15 Bit14 0 Read: TIM Counter Register Low $000D Write: (TCNTL) Reset: $000A Register Name Bit 7 Read: TIM Status and Control Register Write: (TSC) Reset: 2 1 Bit 0 PS2 PS1 PS0 0 0 0 0 0 0 0 0 0 Bit13 Bit12 Bit11 Bit10 Bit9 Bit8 0 0 0 0 0 0 0 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 TOF 0 4 3 0 0 TRST Read: $000B Unimplemented Write: Reset: $000C $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 0 0 = Unimplemented MS1A ELS1B ELS1A TOV1 CH1MAX 0 0 0 0 0 R = Reserved Figure 2-2. Control, Status, and Data Registers (Sheet 2 of 12) Data Sheet 40 MC68HC908BD48 — Rev. 2.0 Memory Map MOTOROLA Memory Map Input/Output (I/O) Section Addr. Register Name Read: TIM Channel 1 Register High Write: (TCH1H) Reset: $0014 Read: TIM Channel 1 Register Low Write: (TCH1L) Reset: $0015 $0016 $0017 $0018 $0019 $001A $001B $001C $001D Read: DDC Master Control Write: Register (DMCR) Reset: Read: DDC Address Register Write: (DADR) Reset: Read: DDC Control Register Write: (DCR) Reset: Read: DDC Status Register Write: (DSR) Reset: Read: DDC Data Transmit Register Write: (DDTR) Reset: DDC Read: Data Receive Register Write: (DDRR) Reset: Read: DDC2 Address Register Write: (D2ADR) Reset: Bit 7 6 5 4 3 2 1 Bit 0 Bit15 Bit14 Bit13 Bit12 Bit11 Bit10 Bit9 Bit8 Bit2 Bit1 Bit0 Indeterminate after reset Bit7 Bit6 Bit5 Bit4 Bit3 Indeterminate after reset ALIF NAKIF BB MAST MRW BR2 BR1 BR0 0 0 0 0 0 0 0 0 DAD7 DAD6 DAD5 DAD4 DAD3 DAD2 DAD1 EXTAD 1 0 1 0 0 0 0 0 DEN DIEN 0 0 TXAK SCLIEN DDC1EN 0 0 0 0 0 0 0 0 RXIF TXIF MATCH SRW RXAK SCLIF TXBE RXBF 0 0 0 0 0 0 1 0 1 0 DTD7 DTD6 DTD5 DTD4 DTD3 DTD2 DTD1 DTD0 1 1 1 1 1 1 1 1 DRD7 DRD6 DRD5 DRD4 DRD3 DRD2 DRD1 DRD0 0 0 0 0 0 0 0 0 D2AD7 D2AD6 D2AD5 D2AD4 D2AD3 D2AD2 D2AD1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Read: HSYNCOE VSYNCOE Configuration Register 0 Write: (CONFIG0) Reset: 0 0 0 0 SOGE 0 = Unimplemented R 0 = Reserved Figure 2-2. Control, Status, and Data Registers (Sheet 3 of 12) MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Memory Map 41 Memory Map Addr. $001E $001F Register Name Bit 7 6 5 4 3 2 Read: IRQ Status and Control Write: Register (INTSCR) Reset: 0 0 0 0 IRQF 0 0 0 0 0 Read: Configuration Register 1 Write: (CONFIG1)† Reset: 0 0 0 0 0 0 0 0PWM3 ACK 1 Bit 0 IMASK MODE 0 0 0 0 SSREC COPRS STOP COPD 0 0 0 0 0 0PWM2 0PWM1 0PWM0 0BRM2 0BRM1 0BRM0 0 0 0 0 0 0 0 1PWM3 1PWM2 1PWM1 1PWM0 1BRM2 1BRM1 1BRM0 0 0 0 0 0 0 0 2PWM3 2PWM2 2PWM1 2PWM0 2BRM2 2BRM1 2BRM0 0 0 0 0 0 0 0 3PWM3 3PWM2 3PWM1 3PWM0 3BRM2 3BRM1 3BRM0 0 0 0 0 0 0 0 4PWM3 4PWM2 4PWM1 4PWM0 4BRM2 4BRM1 4BRM0 0 0 0 0 0 0 0 5PWM3 5PWM2 5PWM1 5PWM0 5BRM2 5BRM1 5BRM0 0 0 0 0 0 0 0 6PWM3 6PWM2 6PWM1 6PWM0 6BRM2 6BRM1 6BRM0 0 0 0 0 0 0 0 7PWM3 7PWM2 7PWM1 7PWM0 7BRM2 7BRM1 7BRM0 0 0 0 0 0 0 0 † One-time writable register after each reset. $0020 $0021 $0022 $0023 $0024 $0025 $0026 $0027 Read: 0PWM4 PWM0 Data Register Write: (0PWM) Reset: 0 Read: 1PWM4 PWM1 Data Register Write: (1PWM) Reset: 0 Read: 2PWM4 PWM2 Data Register Write: (2PWM) Reset: 0 Read: 3PWM4 PWM3 Data Register Write: (3PWM) Reset: 0 Read: 4PWM4 PWM4 Data Register Write: (4PWM) Reset: 0 Read: 5PWM4 PWM5 Data Register Write: (5PWM) Reset: 0 Read: 6PWM4 PWM6 Data Register Write: (6PWM) Reset: 0 Read: 7PWM4 PWM7 Data Register Write: (7PWM) Reset: 0 = Unimplemented R = Reserved Figure 2-2. Control, Status, and Data Registers (Sheet 4 of 12) Data Sheet 42 MC68HC908BD48 — Rev. 2.0 Memory Map MOTOROLA Memory Map Input/Output (I/O) Section Addr. $0028 $0029 $002A $002B $002C $002D $002E Register Name Bit 7 5 4 3 2 1 Bit 0 PWM6E PWM5E PWM4E PWM3E PWM2E PWM1E PWM0E 0 0 0 0 0 0 0 UADD6 UADD5 UADD4 UADD3 UADD2 UADD1 UADD0 0 0 0 0 0 0 0 TBEF RBFF EOPIF RSTIF TBIE RBIE EOPIE RSTIE 0 0 0 0 0 0 0 0 T0SEQ STALL0 TX0E RX0E TP0SIZ3 TP0SIZ2 TP0SIZ1 TP0SIZ0 0 0 0 0 0 0 0 0 RSEQ SETUP TX1ST 0 RPSIZ3 RPSIZ2 RPSIZ1 RPSIZ0 STALL2 STALL1 Read: PWM7E PWM Control Register 1 Write: (PWMCR1) Reset: 0 Read: USBEN USB Address Register Write: (UADR) Reset: 0 Read: USB Interrupt Register Write: (UINTR) Reset: Read: USB Control Register 0 Write: (UCR0) Reset: Read: USB Status Register Write: (USR) Reset: Indeterminate after reset Read: USB Control Register 2 Write: (UCR2) Reset: 0 0 0 0 Read: USB Interrupt Register 1 (UIR1) Write: TXD1F Reset: $002F 6 Read: USB Control Register 1 Write: (UCR1) Reset: TXD1IE PULLEN SUSPND ENABLE2 ENABLE1 0 0 0 0 0 0 RESUMF 0 0 0 0 0 RESUMFR TBEFR RBFFR TXD1FR EOPFR 0 0 0 0 0 TP1SIZ2 TP1SIZ1 TP1SIZ0 0 0 0 0 0 0 T1SEQ ENDADD TX1E 0 0 0 FRESUM TP1SIZ3 0 0 $0030 Read: UE0RD07 UE0RD06 UE0RD05 UE0RD04 UE0RD03 UE0RD02 UE0RD01 UE0RD00 USB Endpoint 0 Data Write: UE0TD07 UE0TD06 UE0TD05 UE0TD04 UE0TD03 UE0TD02 UE0TD01 UE0TD00 Register 0 (UD0R0) Reset: Indeterminate after reset $0031 Read: UE0RD17 UE0RD16 UE0RD15 UE0RD14 UE0RD13 UE0RD12 UE0RD11 UE0RD10 USB Endpoint 0 Data Write: UE0TD17 UE0TD16 UE0TD15 UE0TD14 UE0TD13 UE0TD12 UE0TD11 UE0TD10 Register 1 (UD0R1) Reset: Indeterminate after reset = Unimplemented R = Reserved Figure 2-2. Control, Status, and Data Registers (Sheet 5 of 12) MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Memory Map 43 Memory Map Addr. Register Name Bit 7 6 5 $0032 Read: UE0RD27 UE0RD26 UE0RD25 UE0RD24 UE0RD23 UE0RD22 UE0RD21 UE0RD20 USB Endpoint 0 Data Write: UE0TD27 UE0TD26 UE0TD25 UE0TD24 UE0TD23 UE0TD22 UE0TD21 UE0TD20 Register 2 (UD0R2) Reset: Indeterminate after reset $0033 Read: UE0RD37 UE0RD36 UE0RD35 UE0RD34 UE0RD33 UE0RD32 UE0RD31 UE0RD30 USB Endpoint 0 Data Write: UE0TD37 UE0TD36 UE0TD35 UE0TD34 UE0TD33 UE0TD32 UE0TD31 UE0TD30 Register 3 (UD0R3) Reset: Indeterminate after reset $0034 Read: UE0RD47 UE0RD46 UE0RD45 UE0RD44 UE0RD43 UE0RD42 UE0RD41 UE0RD40 USB Endpoint 0 Data Write: UE0TD47 UE0TD46 UE0TD45 UE0TD44 UE0TD43 UE0TD42 UE0TD41 UE0TD40 Register 4 (UD0R4) Indeterminate after reset Reset: $0035 Read: UE0RD57 UE0RD56 UE0RD55 UE0RD54 UE0RD53 UE0RD52 UE0RD51 UE0RD50 USB Endpoint 0 Data Write: UE0TD57 UE0TD56 UE0TD55 UE0TD54 UE0TD53 UE0TD52 UE0TD51 UE0TD50 Register 5 (UD0R5) Indeterminate after reset Reset: $0036 Read: UE0RD67 UE0RD66 UE0RD65 UE0RD64 UE0RD63 UE0RD62 UE0RD61 UE0RD60 USB Endpoint 0 Data Write: UE0TD67 UE0TD66 UE0TD65 UE0TD64 UE0TD63 UE0TD62 UE0TD61 UE0TD60 Register 6 (UD0R6) Indeterminate after reset Reset: $0037 Read: UE0RD77 UE0RD76 UE0RD75 UE0RD74 UE0RD73 UE0RD72 UE0RD71 UE0RD70 USB Endpoint 0 Data Write: UE0TD77 UE0TD76 UE0TD75 UE0TD74 UE0TD73 UE0TD72 UE0TD71 UE0TD70 Register 7 (UD0R7) Indeterminate after reset Reset: $0038 Read: USB Endpoint 1/2 Data Write: UE1TD07 UE1TD06 UE1TD05 UE1TD04 UE1TD03 UE1TD02 UE1TD01 UE1TD00 Register 0 (UD1R0) Indeterminate after reset Reset: $0039 Read: USB Endpoint 1/2 Data Write: UE1TD17 UE1TD16 UE1TD15 UE1TD14 UE1TD13 UE1TD12 UE1TD11 UE1TD10 Register 1 (UD1R1) Indeterminate after reset Reset: $003A Read: USB Endpoint 1/2 Data Write: UE1TD27 UE1TD26 UE1TD25 UE1TD24 UE1TD23 UE1TD22 UE1TD21 UE1TD20 Register 2 (UD1R2) Indeterminate after reset Reset: $003B Read: USB Endpoint 1/2 Data Write: UE1TD37 UE1TD36 UE1TD35 UE1TD34 UE1TD33 UE1TD32 UE1TD31 UE1TD30 Register 3 (UD1R3) Indeterminate after reset Reset: = Unimplemented 4 3 R 2 1 Bit 0 = Reserved Figure 2-2. Control, Status, and Data Registers (Sheet 6 of 12) Data Sheet 44 MC68HC908BD48 — Rev. 2.0 Memory Map MOTOROLA Memory Map Input/Output (I/O) Section Addr. Register Name Bit 7 6 5 4 3 2 1 Bit 0 $003C Read: USB Endpoint 1/2 Data Write: UE1TD47 UE1TD46 UE1TD45 UE1TD44 UE1TD43 UE1TD42 UE1TD41 UE1TD40 Register 4 (UD1R4) Indeterminate after reset Reset: $003D Read: USB Endpoint 1/2 Data Write: UE1TD57 UE1TD56 UE1TD55 UE1TD54 UE1TD53 UE1TD52 UE1TD51 UE1TD50 Register 5 (UD1R5) Indeterminate after reset Reset: $003E Read: USB Endpoint 1/2 Data Write: UE1TD67 UE1TD66 UE1TD65 UE1TD64 UE1TD63 UE1TD62 UE1TD61 UE1TD60 Register 6 (UD1R6) Indeterminate after reset Reset: $003F Read: USB Endpoint 1/2 Data Write: UE1TD77 UE1TD76 UE1TD75 UE1TD74 UE1TD73 UE1TD72 UE1TD71 UE1TD70 Register 7 (UD1R7) Indeterminate after reset Reset: $0040 Read: Sync Processor Control and Status Register Write: (SPCSR) Reset: $0041 $0042 $0043 $0044 VPOL HPOL 0 0 0 VF11 VF10 VF9 VF8 0 0 0 0 0 VF5 VF4 VF3 VF2 VF1 VF0 0 0 0 0 0 0 0 HFH7 HFH6 HFH5 HFH4 HFH3 HFH2 HFH1 HFH0 0 0 0 0 0 0 0 0 0 0 HFL4 HFL3 HFL2 HFL1 HFL0 0 0 0 0 0 0 0 COINV R BPOR SOUT 0 0 0 0 VSIE VEDGE 0 0 Read: Vertical Frequency High Register Write: (VFHR) Reset: VOF VSIF COMP VINVO HINVO 0 0 0 0 0 VF12 CPW1 CPW0 0 0 0 Read: Vertical Frequency Low Register Write: (VFLR) Reset: VF7 VF6 0 Read: Hsync Frequency High Register Write: (HFHR) Reset: Read: HOVER Hsync Frequency Low Register Write: (HFLR) Reset: 0 $0045 Read: VSYNCS HSYNCS Sync Processor I/O Control Register Write: (SPIOCR) Reset: 0 0 0 = Unimplemented SOGSEL CLAMPOE 0 R 0 = Reserved Figure 2-2. Control, Status, and Data Registers (Sheet 7 of 12) MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Memory Map 45 Memory Map Addr. $0046 Register Name Bit 7 Read: Sync Processor Control Register 1 Write: (SPCR1) Reset: Read: H&V Sync Output Control $0047 Register Write: (HVOCR) Reset: LVSIE 0 R 0 6 5 4 3 2 1 Bit 0 HPS1 HPS0 R R ATPOL FSHF 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 IICDATE IICSCLE 0 0 0 0 0 0 0 MMNAKIF MMBB MMAST MMRW MMBR2 MMBR1 MMBR0 0 0 0 0 0 0 0 MMAD6 MMAD5 MMAD4 MMAD3 MMAD2 MMAD1 MMEXTAD 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 LVSIF 0 HVOCR2 HVOCR1 HVOCR0 0 0 0 Read: Unimplemented Write: $0048 Reset: Read: Port D Configuration Write: Register (PDCR) Reset: $0049 $004A 0 0 Read: Multi-Master IIC MMALIF Master Control Register Write: (MIMCR) Reset: 0 Read: Multi-Master IIC Address MMAD7 $004B Register Write: (MMADR) Reset: 1 Read: Multi-Master IIC Control Register Write: (MMCR) Reset: $004C $004F MMIEN 0 0 Read: MMRXIF Multi-Master IIC 0 Status Register Write: (MMSR) Reset: 0 $004D $004E MMEN Read: Multi-Master IIC MMTD7 Data Transmit Register Write: (MMDTR) Reset: 1 Multi-Master IIC Read: MMRD7 Data Receive Register Write: (MMDRR) Reset: 0 MMTXIF CLAMPE DDCSCLE DDCDATE USBD–E MMTXAK 0 MMATCH MMSRW MMRXAK 0 USBD+E MMTXBE MMRXBF 0 0 0 0 1 0 1 0 MMTD6 MMTD5 MMTD4 MMTD3 MMTD2 MMTD1 MMTD0 1 1 1 1 1 1 1 MMRD6 MMRD5 MMRD4 MMRD3 MMRD2 MMRD1 MMRD0 0 0 0 0 0 0 0 = Unimplemented R = Reserved Figure 2-2. Control, Status, and Data Registers (Sheet 8 of 12) Data Sheet 46 MC68HC908BD48 — Rev. 2.0 Memory Map MOTOROLA Memory Map Input/Output (I/O) Section Addr. Register Name Bit 7 6 5 4 3 2 1 Bit 0 8PWM3 8PWM2 8PWM1 8PWM0 8BRM2 8BRM1 8BRM0 0 0 0 0 0 0 0 9PWM3 9PWM2 9PWM1 9PWM0 9BRM2 9BRM1 9BRM0 0 0 0 0 0 0 0 10BRM2 10BRM1 10BRM0 0 0 0 11BRM2 11BRM1 11BRM0 0 0 0 12BRM2 12BRM1 12BRM0 0 0 0 13BRM2 13BRM1 13BRM0 0 0 0 14BRM2 14BRM1 14BRM0 0 0 0 15BRM2 15BRM1 15BRM0 0 0 0 PWM9E PWM8E 0 0 Read: $0050 Unimplemented Write: Reset: $0051 $0052 $0053 $0054 $0055 $0056 $0057 $0058 $0059 Read: 8PWM4 PWM8 Data Register Write: (8PWM) Reset: 0 Read: 9PWM4 PWM9 Data Register Write: (9PWM) Reset: 0 Read: 10PWM4 10PWM3 10PWM2 10PWM1 10PWM0 PWM10 Data Register Write: (10PWM) Reset: 0 0 0 0 0 Read: 11PWM4 11PWM3 11PWM2 11PWM1 11PWM0 PWM11 Data Register Write: (11PWM) Reset: 0 0 0 0 0 Read: 12PWM4 12PWM3 12PWM2 12PWM1 12PWM0 PWM12 Data Register Write: (12PWM) Reset: 0 0 0 0 0 Read: 13PWM4 13PWM3 13PWM2 13PWM1 13PWM0 PWM13 Data Register Write: (13PWM) Reset: 0 0 0 0 0 Read: 14PWM4 PWM14 Data Register Write: (14PWM) Reset: 0 PWM3 0 14PWM2 14PWM1 14PWM0 0 0 0 Read: 15PWM4 15PWM3 15PWM2 15PWM1 15PWM0 PWM15 Data Register Write: (15PWM) Reset: 0 0 0 0 0 Read: PWM15E PWM14E PWM13E PWM12E PWM11E PWM10E PWM Control Register 2 Write: (PWMCR2) Reset: 0 0 0 0 0 0 = Unimplemented R = Reserved Figure 2-2. Control, Status, and Data Registers (Sheet 9 of 12) MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Memory Map 47 Memory Map Addr. Register Name Bit 7 6 5 4 3 2 1 Bit 0 AIEN ADCO ADCH4 ADCH3 ADCH2 ADCH1 ADCH0 0 0 0 1 1 1 1 1 AD7 AD6 AD5 AD4 AD3 AD2 AD1 AD0 Read: Unimplemented Write: $005A Reset: Read: Unimplemented Write: $005B Reset: Read: Unimplemented Write: $005C Reset: $005D Read: ADC Status and Control Write: Register (ADSCR) Reset: $005E Read: ADC Data Register Write: (ADR) Reset: Read: ADC Input Clock Register $005F Write: (ADICLK) Reset: Read: SIM Break Status Register $FE00 Write: (SBSR) Reset: COCO Unaffected after Reset 0 0 0 0 0 0 0 0 0 0 0 R R R R R 0 0 0 0 0 0 0 0 POR PIN COP ILOP ILAD 0 0 0 1 0 0 0 0 0 0 0 R R R R R R R R 0 0 0 0 0 0 0 0 ADIV2 ADIV1 ADIV0 0 0 R SBSW Note R Note: Writing a logic 0 clears SBSW. Read: SIM Reset Status Register $FE01 Write: (SRSR) POR: Read: $FE02 Reserved Write: Reset: = Unimplemented R = Reserved Figure 2-2. Control, Status, and Data Registers (Sheet 10 of 12) Data Sheet 48 MC68HC908BD48 — Rev. 2.0 Memory Map MOTOROLA Memory Map Input/Output (I/O) Section Addr. $FE03 Register Name Read: SIM Break Flag Control Write: Register (SBFCR) Reset: Bit 7 6 5 4 3 2 1 Bit 0 BCFE R R R R R R R 0 Read: Interrupt Status Register 1 $FE04 Write: (INT1) Reset: IF6 IF5 IF4 IF3 IF2 IF1 0 0 R R R R R R R R 0 0 0 0 0 0 0 0 Read: Interrupt Status Register 2 $FE05 Write: (INT2) Reset: 0 0 0 0 IF10 IF9 IF8 IF7 R R R R R R R R 0 0 0 0 0 0 0 0 R R R R R R R R Reset: 0 0 0 0 0 0 0 0 Read: FLASH Control Register Write: (FLCR) Reset: 0 0 0 0 HVEN MASS ERASE PGM 0 0 0 0 0 0 0 0 BPR7 BPR6 BPR5 BPR4 BPR3 BPR2 BPR1 0 0 0 0 0 0 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 0 0 0 0 0 0 0 0 R R R R R R R R 0 0 0 0 0 0 0 0 Bit15 Bit14 Bit13 Bit12 Bit11 Bit10 Bit9 Bit8 0 0 0 0 0 0 0 0 Read: $FE06 $FE07 $FE08 Reserved Write: Read: FLASH Block Protect Write: Register (FLBPR) Reset: Read: $FE09 Reserved Write: Reset: Read: $FE0A Reserved Write: Reset: Read: $FE0B Reserved Write: Reset: $FE0C Read: Break Address High Write: Register (BRKH) Reset: = Unimplemented R 0 = Reserved Figure 2-2. Control, Status, and Data Registers (Sheet 11 of 12) MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Memory Map 49 Memory Map Addr. Register Name Read: Break Address low Write: Register (BRKL) Reset: $FE0D Read: Break Status and Control Write: $FE0E Register (BRKSCR) Reset: $FFFF Read: COP Control Register Write: (COPCTL) Reset: Bit 7 6 5 4 3 2 1 Bit 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 Figure 2-2. Control, Status, and Data Registers (Sheet 12 of 12) Data Sheet 50 MC68HC908BD48 — Rev. 2.0 Memory Map MOTOROLA Memory Map Input/Output (I/O) Section . Table 2-1. Vector Addresses Vector Priority Lowest INT Flag — IF10 IF9 IF8 IF7 IF6 IF5 IF4 IF3 IF2 IF1 — Highest — MC68HC908BD48 — Rev. 2.0 MOTOROLA Address Vector $FFE6 Reserved $FFE7 Reserved $FFE8 ADC Interrupt Vector (High) $FFE9 ADC Interrupt Vector (Low) $FFEA MMIIC Vector (High) $FFEB MMIIC Vector (Low) $FFEC Sync Processor Vector (High) $FFED Sync Processor Vector (Low) $FFEE TIM Overflow Vector (High) $FFEF TIM Overflow Vector (Low) $FFF0 TIM Channel 1 Vector (High) $FFF1 TIM Channel 1 Vector (Low) $FFF2 TIM Channel 0 Vector (High) $FFF3 TIM Channel 0 Vector (Low) $FFF4 Reserved $FFF5 Reserved $FFF6 DDC12AB Vector (High) $FFF7 DDC12AB Vector (Low) $FFF8 USB Vector (High) $FFF9 USB Vector (Low) $FFFA IRQ Vector (High) $FFFB IRQ Vector (Low) $FFFC SWI Vector (High) $FFFD SWI Vector (Low) $FFFE Reset Vector (High) $FFFF Reset Vector (Low) Data Sheet Memory Map 51 Memory Map Data Sheet 52 MC68HC908BD48 — Rev. 2.0 Memory Map MOTOROLA Data Sheet – MC68HC908BD48 Section 3. Random-Access Memory (RAM) 3.1 Contents 3.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 3.3 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53 3.2 Introduction This section describes the 1,024 bytes of RAM (random-access memory). 3.3 Functional Description Addresses $0080 through $047F 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 128 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 out of page zero, direct addressing mode instructions can efficiently access 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 compatibility, the H register is not stacked. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Random-Access Memory (RAM) 53 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: Be careful when using nested subroutines. The CPU may overwrite data in the RAM during a subroutine or during the interrupt stacking operation. Data Sheet 54 MC68HC908BD48 — Rev. 2.0 Random-Access Memory (RAM) MOTOROLA Data Sheet – MC68HC908BD48 Section 4. FLASH Memory 4.1 Contents 4.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 4.3 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56 4.4 FLASH Control Register (FLCR) . . . . . . . . . . . . . . . . . . . . . . . 56 4.5 FLASH Block Erase Operation . . . . . . . . . . . . . . . . . . . . . . . . . 57 4.6 FLASH Mass Erase Operation . . . . . . . . . . . . . . . . . . . . . . . . . 58 4.7 FLASH Program Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . .59 4.8 FLASH Block Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 4.9 FLASH Block Protect Register (FLBPR). . . . . . . . . . . . . . . . . . 61 4.2 Introduction This section describes the operation of the embedded FLASH memory. The FLASH memory can be read, programmed, and erased from a single external supply through the use of the internal charge pump for program and erase. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet FLASH Memory 55 FLASH Memory 4.3 Functional Description The FLASH memory is an array of 48,128 bytes with an additional 26 bytes of user vectors. An erased bit reads as logic 1 and a programmed bit reads as a logic 0. Program and erase operations are facilitated through control bits in a memory mapped FLASH control register (FLCR). The address ranges for the user memory and vectors are: • $4000–$FBFF; user memory • $FE07; FLASH control register • $FE08; FLASH block protect register • $FFE6–$FFFF; these locations are reserved for user-defined interrupt and reset vectors Programming tools are available from Motorola. Contact your local Motorola representative for more information. 4.4 FLASH Control Register (FLCR) The FLASH control register (FLCR) controls FLASH program and erase operations. Address: Read: $FE07 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 = Unimplemented Figure 4-1. FLASH Control Register (FLCR) Data Sheet 56 MC68HC908BD48 — Rev. 2.0 FLASH Memory MOTOROLA FLASH Memory FLASH Block Erase Operation HVEN — High-Voltage Enable Bit This read/write bit enables the charge pump to drive high voltages for program and erase operations in the array. HVEN can only be set if either PGM = 1 or ERASE = 1 and the proper sequence for program or erase 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 Setting this read/write bit configures the 48,128 bytes FLASH array for mass erase operation. 1 = Mass Erase operation selected 0 = Mass Erase operation not selected ERASE — Erase Control Bit This read/write bit configures the memory for erase operation. ERASE is interlocked with the PGM bit such that both bits cannot be equal to 1 or 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. PGM is interlocked with the ERASE bit such that both bits cannot be equal to 1 or set to 1 at the same time. 1 = Program operation selected 0 = Program operation not selected 4.5 FLASH Block Erase Operation Use the following procedure to erase a block (512 bytes) of FLASH memory: 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 block address range desired. 3. Wait for a time, tnvs (min. 5µs) MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet FLASH Memory 57 FLASH Memory 4. Set the HVEN bit. 5. Wait for a time, tErase (min. 2ms) 6. Clear the ERASE bit. 7. Wait for a time, tnvh (min. 5µs) 8. Clear the HVEN bit. 9. After a time, trcv (min. 1µs), the memory can be accessed again in read mode. 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. 4.6 FLASH Mass Erase Operation Use the following procedure to erase 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 FLASH memory address range. 3. Wait for a time, tnvs (5µs). 4. Set the HVEN bit. 5. Wait for a time, tMErase (4ms). 6. Clear the ERASE bit. 7. Wait for a time, tnvhl (100µs). 8. Clear the HVEN bit. 9. After time, trcv (1µs), the memory can be accessed again in read mode. 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. Data Sheet 58 MC68HC908BD48 — Rev. 2.0 FLASH Memory MOTOROLA FLASH Memory FLASH Program Operation 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, and $XXC0. Use this step-by-step procedure to program a row of FLASH memory (Figure 4-2 is a flowchart representation): NOTE: In order to avoid program disturbs, the row must be erased before any byte on that row is programmed. 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 row address range desired. 3. Wait for a time, tnvs (min. 5µs). 4. Set the HVEN bit. 5. Wait for a time, tpgs (min. 10µs). 6. Write data to the FLASH address to be programmed. 7. Wait for time, tPROG (min. 20µs). 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 (min. 5µs). 11. Clear the HVEN bit. 12. After time, trcv (min 1µs), 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 21.15 Memory Characteristics. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet FLASH Memory 59 FLASH Memory Algorithm for programming a row (64 bytes) of FLASH memory 1 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 7 to step 7), 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 4-2. FLASH Programming Flowchart Data Sheet 60 MC68HC908BD48 — Rev. 2.0 FLASH Memory MOTOROLA FLASH Memory FLASH Block Protection 4.8 FLASH Block 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 for protecting 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 at the bottom of the FLASH memory ($FFFF). When the memory is protected, the HVEN bit cannot be set in either ERASE or PROGRAM operations. 4.9 FLASH Block Protect Register (FLBPR) The FLASH block protect register is implemented as an 7-bit I/O register. The BPR bit content of the register determines the starting location of the protected range within the FLASH memory. Address: $FE08 Bit 7 6 5 4 3 2 1 BPR7 BPR6 BPR5 BPR4 BPR3 BPR2 BPR1 0 0 0 0 0 0 0 Read: Bit 0 0 Write: Reset: 0 = Unimplemented Figure 4-3. FLASH Block Protect Register (FLBPR) BPR[7:1] — FLASH Block Protect Bits These seven bits represent bits [15:9] of a 16-bit memory address. Bits [8:0] are logic 0s. 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. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet FLASH Memory 61 FLASH Memory 16-bit memory address Start address of FLASH block protect FLBPR value 0 0 0 0 0 0 0 0 0 Figure 4-4. FLASH Block Protect Start Address Examples of protect FLASH memory: BPR[7:0] FLASH Memory Protected Range $00–3E The entire FLASH memory is not protected. $40 The entire FLASH memory is protected. $42 (0100 0010) $4200 (0100 0010 0000 0000) to $FFFF $44 (0100 0100) $4400 (0100 0100 0000 0000) to $FFFF and so on... $F8 (1111 1000) $F800 (1111 1000 0000 0000) to $FFFF $FA (1111 1010) $FA00 (1111 1010 0000 0000) to $FFFF Note: The user FLASH vectors from $FFE6 to $FFFF are always protected, and can only be erased by a FLASH mass erase operation. Data Sheet 62 MC68HC908BD48 — Rev. 2.0 FLASH Memory MOTOROLA Data Sheet – MC68HC908BD48 Section 5. Configuration Register (CONFIG) 5.1 Contents 5.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 5.3 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .63 5.3.1 Configuration Register 0. . . . . . . . . . . . . . . . . . . . . . . . . . . .64 5.3.2 Configuration Register 1. . . . . . . . . . . . . . . . . . . . . . . . . . . .65 5.2 Introduction This section describes the configuration registers, CONFIG0 and CONFIG1. The configuration registers enable or disable these options: • Sync Processor HSYNCO output pin • Sync Processor VSYNCO output pin • Sync Processor SOG input pin • Stop mode recovery time (32 OSCXCLK cycles or 4096 OSCXCLK cycles) • COP timeout period (218 – 24 or 213 – 24 OSCXCLK cycles) • STOP instruction • Computer operating properly module (COP) 5.3 Functional Description The configuration registers are used in the initialization of various options. The configuration registers can be written once after each reset. All of the configuration register bits are cleared during reset. Since the various options affect the operation of the MCU, it is recommended that these registers be written immediately after reset. The configuration MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Configuration Register (CONFIG) 63 Configuration Register (CONFIG) registers are located at $001D and $001F. The configuration register may be read at anytime. 5.3.1 Configuration Register 0 Address: $001D Bit 7 6 5 Read: HSYNCOE VSYNCOE 4 3 2 1 Bit 0 0 0 0 0 0 0 0 0 0 0 SOGE Write: Reset: 0 0 0 = Unimplemented Figure 5-1. Configuration Register 0 (CONFIG0) HSYNCOE — VSYNCO Enable This bit is set to configure the PTE1/HSYNCO pin for HSYNCO output function. Reset clears this bit. 1 = PTE1/HSYNCO pin configured as HSYNCO pin 0 = PTE1/HSYNCO pin configured as standard I/O pin VSYNCOE — VSYNCO Enable This bit is set to configure the PTE2/VSYNCO pin for VSYNCO output function. Reset clears this bit. 1 = PTE2/VSYNCO pin configured as VSYNCO pin 0 = PTE2/VSYNCO pin configured as standard I/O pin SOGE — SOG Enable This bit is set to configure the PTE0/SOG/TCH0 pin for SOG output function. Reset clears this bit. 1 = PTE0/SOG/TCH0 pin configured as SOG pin 0 = PTE0/SOG/TCH0 pin configured as standard I/O or TCH0 pin. TCH0 function is configured by ELS0B and ELS0A bits in TSC0 (bits 3 and 2 in $0010). (See 10.10.4 TIM Channel Status and Control Registers (TSC0:TSC1).) Data Sheet 64 MC68HC908BD48 — Rev. 2.0 Configuration Register (CONFIG) MOTOROLA Configuration Register (CONFIG) Functional Description 5.3.2 Configuration Register 1 Address: Read: $001F Bit 7 6 5 4 0 0 0 0 3 2 1 Bit 0 SSREC COPRS STOP COPD 0 0 0 0 Write: Reset: 0 0 0 0 = Unimplemented Figure 5-2. Configuration Register 1 (CONFIG1) SSREC — Short Stop Recovery Bit SSREC enables the CPU to exit stop mode with a delay of 32 OSCXCLK cycles instead of a 4096-OSCXCLK cycle delay. 1 = Stop mode recovery after 32 OSCXCLK cycles 0 = Stop mode recovery after 4096 OSCXCLKC cycles NOTE: Exiting stop mode by pulling reset will result in the long stop recovery. If using an external crystal oscillator, do not set the SSREC bit. COPRS — COP Rate Select Bit COPRS selects the COP timeout period. Reset clears COPRS. (See Section 19. Computer Operating Properly (COP).) 1 = COP timeout period = 213 – 24 CGMXCLK cycles 0 = COP timeout period = 218 – 24 CGMXCLK 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 19. Computer Operating Properly (COP).) 1 = COP module disabled 0 = COP module enabled MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Configuration Register (CONFIG) 65 Configuration Register (CONFIG) Data Sheet 66 MC68HC908BD48 — Rev. 2.0 Configuration Register (CONFIG) MOTOROLA Data Sheet – MC68HC908BD48 Section 6. Central Processor Unit (CPU) 6.1 Contents 6.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 6.3 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 6.4 CPU Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 6.4.1 Accumulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 6.4.2 Index Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 6.4.3 Stack Pointer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 6.4.4 Program Counter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 6.4.5 Condition Code Register . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 6.5 Arithmetic/Logic Unit (ALU) . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 6.6 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 6.6.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .74 6.6.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .75 6.7 CPU During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . 75 6.8 Instruction Set Summary 6.9 Opcode Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 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 (Motorola document order number CPU08RM/AD) contains a description of the CPU instruction set, addressing modes, and architecture. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Central Processor Unit (CPU) 67 Central Processor Unit (CPU) 6.3 Features • 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 • 8-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 6.4 CPU Registers Figure 6-1 shows the five CPU registers. CPU registers are not part of the memory map. Data Sheet 68 MC68HC908BD48 — Rev. 2.0 Central Processor Unit (CPU) MOTOROLA Central Processor Unit (CPU) CPU Registers 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) MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Central Processor Unit (CPU) 69 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. Data Sheet 70 MC68HC908BD48 — Rev. 2.0 Central Processor Unit (CPU) MOTOROLA Central Processor Unit (CPU) CPU Registers 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) 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) 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 MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Central Processor Unit (CPU) 71 Central Processor Unit (CPU) 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 Data Sheet 72 MC68HC908BD48 — Rev. 2.0 Central Processor Unit (CPU) MOTOROLA 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 MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Central Processor Unit (CPU) 73 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 (Motorola 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: • 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 Data Sheet 74 MC68HC908BD48 — Rev. 2.0 Central Processor Unit (CPU) MOTOROLA 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. 6.8 Instruction Set Summary 6.9 Opcode Map See Table 6-2. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Central Processor Unit (CPU) 75 Central Processor Unit (CPU) 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 ff 4 1 1 4 3 5 – – – – – – 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 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 Logical AND Arithmetic Shift Left (Same as LSL) ASR opr ASRA ASRX ASR opr,X ASR opr,X ASR opr,SP Arithmetic Shift Right BCC rel Branch if Carry Bit Clear BCLR n, opr C 0 b7 b0 C b7 Clear Bit n in M b0 PC ← (PC) + 2 + rel ? (C) = 0 Mn ← 0 Data Sheet 76 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 ff ee ff ff ff ff 4 1 1 4 3 5 MC68HC908BD48 — Rev. 2.0 Central Processor Unit (CPU) MOTOROLA Central Processor Unit (CPU) Opcode Map Effect on CCR V H I N Z C Cycles Description Operand Operation Opcode Source Form Address Mode Table 6-1. Instruction Set Summary (Continued) 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 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 3 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 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 MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Central Processor Unit (CPU) 77 Central Processor Unit (CPU) Table 6-1. Instruction Set Summary (Continued) 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 Description V H I N Z C 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 Cycles Operand Effect on CCR Opcode Operation Address Mode Source Form CLC Clear Carry Bit C←0 – – – – – 0 INH 98 1 CLI Clear Interrupt Mask I←0 – – 0 – – – INH 9A 2 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 CLR opr CLRA CLRX CLRH CLR opr,X CLR ,X CLR opr,SP Clear Data Sheet 78 dd ff ff 3 1 1 1 3 2 4 MC68HC908BD48 — Rev. 2.0 Central Processor Unit (CPU) MOTOROLA Central Processor Unit (CPU) Opcode Map Effect on CCR V H I N Z C CMP #opr CMP opr CMP opr CMP opr,X CMP opr,X CMP ,X CMP opr,SP CMP opr,SP Compare A with M (A) – (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 ← (M) = $FF – (M) A ← (A) = $FF – (M) X ← (X) = $FF – (M) M ← (M) = $FF – (M) M ← (M) = $FF – (M) M ← (M) = $FF – (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 ff ee ff ff 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 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 A ← (H:A)/(X) H ← Remainder – – – – R R INH 52 (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 DEC opr DECA DECX DEC opr,X DEC ,X DEC opr,SP Decrement DIV Divide MC68HC908BD48 — Rev. 2.0 MOTOROLA 2 3 4 4 3 2 4 5 4 1 1 4 3 5 (H:X) – (M:M + 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 Cycles Description Operand Operation Opcode Source Form Address Mode Table 6-1. Instruction Set Summary (Continued) ff ff 5 3 3 5 4 6 4 1 1 4 3 5 7 Data Sheet Central Processor Unit (CPU) 79 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 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) C 0 b7 b0 Data Sheet 80 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 (Continued) 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 MC68HC908BD48 — Rev. 2.0 Central Processor Unit (CPU) MOTOROLA Central Processor Unit (CPU) Opcode Map 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 (Continued) 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 MC68HC908BD48 — Rev. 2.0 MOTOROLA 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 Data Sheet Central Processor Unit (CPU) 81 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 (Continued) 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 Store X in M Data Sheet 82 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 MC68HC908BD48 — Rev. 2.0 Central Processor Unit (CPU) MOTOROLA Central Processor Unit (CPU) Opcode Map 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 (Continued) 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 MC68HC908BD48 — Rev. 2.0 MOTOROLA dd ff ff 3 1 1 3 2 4 Data Sheet Central Processor Unit (CPU) 83 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 — 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 Data Sheet 84 Cycles Effect on CCR Description Operand Operation Opcode Source Form Address Mode Table 6-1. Instruction Set Summary (Continued) MC68HC908BD48 — Rev. 2.0 Central Processor Unit (CPU) MOTOROLA MC68HC908BD48 — Rev. 2.0 MOTOROLA Table 6-2. Opcode Map Bit Manipulation DIR DIR MSB Branch REL DIR INH 3 4 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 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 Central Processor Unit (CPU) 0 Read-Modify-Write INH IX1 5 6 7 8 9 A B C E F Data Sheet 85 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 5 Cycles 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) Data Sheet 86 MC68HC908BD48 — Rev. 2.0 Central Processor Unit (CPU) MOTOROLA Data Sheet – MC68HC908BD48 Section 7. System Integration Module (SIM) 7.1 Contents 7.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 7.3 SIM Bus Clock Control and Generation . . . . . . . . . . . . . . . . . . 91 7.3.1 Bus Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 7.3.2 Clock Start-Up from POR . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 7.3.3 Clocks in Stop Mode and Wait Mode . . . . . . . . . . . . . . . . . . 91 7.4 Reset and System Initialization. . . . . . . . . . . . . . . . . . . . . . . . . 92 7.4.1 External Pin Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 7.4.2 Active Resets from Internal Sources . . . . . . . . . . . . . . . . . . 93 7.4.2.1 Power-On Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .94 7.4.2.2 Computer Operating Properly (COP) Reset. . . . . . . . . . . 95 7.4.2.3 Illegal Opcode Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96 7.4.2.4 Illegal Address Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . .96 7.5 SIM Counter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96 7.5.1 SIM Counter During Power-On Reset . . . . . . . . . . . . . . . . . 96 7.5.2 SIM Counter During Stop Mode Recovery . . . . . . . . . . . . . . 97 7.5.3 SIM Counter and Reset States. . . . . . . . . . . . . . . . . . . . . . . 97 7.6 Exception Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .97 7.6.1 Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98 7.6.1.1 Hardware Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 7.6.1.2 SWI Instruction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101 7.6.2 Interrupt Status Registers. . . . . . . . . . . . . . . . . . . . . . . . . . 101 7.6.2.1 Interrupt Status Register 1 . . . . . . . . . . . . . . . . . . . . . . . 103 7.6.2.2 Interrupt Status Register 2 . . . . . . . . . . . . . . . . . . . . . . . 103 7.6.3 Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104 7.6.4 Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104 7.6.5 Status Flag Protection in Break Mode . . . . . . . . . . . . . . . . 104 7.7 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105 MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet System Integration Module (SIM) 87 System Integration Module (SIM) 7.7.1 7.7.2 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .105 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .106 7.8 SIM Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108 7.8.1 SIM Break Status Register (SBSR) . . . . . . . . . . . . . . . . . . 108 7.8.2 SIM Reset Status Register (SRSR) . . . . . . . . . . . . . . . . . . 109 7.8.3 SIM Break Flag Control Register (SBFCR) . . . . . . . . . . . . 110 7.2 Introduction This section describes the system integration module, which supports up to 16 external and/or internal interrupts. Together with the CPU, the SIM controls all MCU activities. A block diagram of the SIM is shown in Figure 7-1. Table 7-1 shows a summary of the SIM I/O registers. The SIM is a system state controller that coordinates CPU and exception timing. 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 • CPU enable/disable timing • Modular architecture expandable to 128 interrupt sources Data Sheet 88 MC68HC908BD48 — Rev. 2.0 System Integration Module (SIM) MOTOROLA 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 OSCILLATOR) OSCOUT (FROM OSCILLATOR) ÷2 CLOCK CONTROL RESET PIN LOGIC CLOCK GENERATORS INTERNAL CLOCKS LVI (FROM LVI MODULE) POR CONTROL MASTER RESET CONTROL RESET PIN CONTROL SIM RESET STATUS REGISTER ILLEGAL OPCODE (FROM CPU) ILLEGAL ADDRESS (FROM ADDRESS MAP DECODERS) COP (FROM COP MODULE) RESET INTERRUPT CONTROL AND PRIORITY DECODE INTERRUPT SOURCES CPU INTERFACE Figure 7-1. SIM Block Diagram MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet System Integration Module (SIM) 89 System Integration Module (SIM) Table 7-1. SIM I/O Register Summary Addr. Register Name Bit 7 6 5 4 3 2 R R R R R R 0 0 0 0 0 0 0 0 POR PIN COP ILOP ILAD 0 0 0 1 0 0 0 0 0 0 0 BCFE R R R R R R R Read: SIM Break Status Register $FE00 Write: (SBSR) Reset: Read: SIM Reset Status Write: Register (SRSR) POR: $FE01 $FE03 Read: SIM Break Flag Control Write: Register (SBFCR) Reset: 1 Bit 0 SBSW Note R 0 Read: Interrupt Status Register 1 $FE04 Write: (INT1) Reset: IF6 IF5 IF4 IF3 IF2 IF1 0 0 R R R R R R R R 0 0 0 0 0 0 0 0 Read: Interrupt Status Register 2 $FE05 (INT2) Write: 0 0 0 0 IF10 IF9 IF8 IF7 R R R R R R R R Reset: 0 0 0 0 0 0 0 0 = Unimplemented Note: Writing a logic 0 clears SBSW. R = Reserved Table 7-2 shows the internal signal names used in this section. Table 7-2. Signal Name Conventions Signal Name Description OSCXCLK Buffered version 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 divided by four) 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 Data Sheet 90 MC68HC908BD48 — Rev. 2.0 System Integration Module (SIM) MOTOROLA System Integration Module (SIM) SIM Bus Clock Control and Generation 7.3 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 7-2. From SIM OSCXCLK ÷2 OSCOUT SIM COUNTER BUS CLOCK GENERATORS ÷2 SIMOSCEN OSCILLATOR OSC1 SIM OSC2 Figure 7-2. OSC Clock Signals 7.3.1 Bus Timing In user mode, the internal bus frequency is the oscillator frequency (OSCXCLK) divided by four. 7.3.2 Clock Start-Up from POR When the power-on reset 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 is driven low by the SIM during this entire period. The IBUS clocks start upon completion of the timeout. 7.3.3 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 32 OSCXCLK cycles. (See 7.7.2 Stop Mode.) MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet System Integration Module (SIM) 91 System Integration Module (SIM) 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. 7.4 Reset and System Initialization The MCU has the following reset sources: • Power-on reset module (POR) • External reset pin (RST) • Computer operating properly module (COP) • Illegal opcode • Illegal address 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 7.5 SIM Counter), but an external reset does not. Each of the resets sets a corresponding bit in the SIM reset status register (SRSR) (see 7.8 SIM Registers). 7.4.1 External Pin Reset Pulling the asynchronous RST pin low halts all processing. The PIN bit of the SIM reset status register (SRSR) is set as long as RST is held low for a minimum of 67 OSCXCLK cycles, assuming that the POR was the source of the reset (see Table 7-3. PIN Bit Set Timing). Figure 7-3 shows the relative timing. Table 7-3. PIN Bit Set Timing Reset Type Number of Cycles Required to Set PIN POR 4163 (4096 + 64 + 3) All others 67 (64 + 3) Data Sheet 92 MC68HC908BD48 — Rev. 2.0 System Integration Module (SIM) MOTOROLA System Integration Module (SIM) Reset and System Initialization OSCOUT RST IAB VECT H VECT L PC Figure 7-3. External Reset Timing 7.4.2 Active Resets from Internal Sources SIM module in HC08 has the capability to drive the RST pin low when internal reset events occur. 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 74. Internal Reset Timing). An internal reset can be caused by an illegal address, illegal opcode, COP timeout, or POR (see Figure 7-5. Sources of Internal Reset). Note that for 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 7-4. IRST RST RST PULLED LOW BY MCU 32 CYCLES 32 CYCLES OSCXCLK IAB VECTOR HIGH Figure 7-4. Internal Reset Timing The COP reset is asynchronous to the bus clock. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet System Integration Module (SIM) 93 System Integration Module (SIM) ILLEGAL ADDRESS RST ILLEGAL OPCODE RST COPRST INTERNAL RESET POR Figure 7-5. 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. 7.4.2.1 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 SIM reset status register (SRSR) is set and all other bits in the register are cleared. Data Sheet 94 MC68HC908BD48 — Rev. 2.0 System Integration Module (SIM) MOTOROLA System Integration Module (SIM) Reset and System Initialization OSC1 PORRST 4096 CYCLES 32 CYCLES 32 CYCLES OSCXCLK OSCOUT RST $FFFE IAB $FFFF Figure 7-6. POR Recovery 7.4.2.2 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 SIM reset status register (SRSR). 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 bits 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 is held at VTST 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 pin or the IRQ pin. This prevents the COP from becoming disabled as a result of external noise. During a break state, VTST on the RST pin disables the COP module. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet System Integration Module (SIM) 95 System Integration Module (SIM) 7.4.2.3 Illegal Opcode Reset The SIM decodes signals from the CPU to detect illegal instructions. An illegal instruction sets the ILOP bit in the SIM reset status register (SRSR) and causes a reset. If the stop enable bit, STOP, in the configure register 1 (CONFIG1) is logic zero, 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. 7.4.2.4 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 SIM reset status register (SRSR) 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. 7.5 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 prescaler for the computer operating properly module (COP). The SIM counter overflow supplies the clock for the COP module. The SIM counter is 12 bits long and is clocked by the falling edge of OSCXCLK. 7.5.1 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. Data Sheet 96 MC68HC908BD48 — Rev. 2.0 System Integration Module (SIM) MOTOROLA System Integration Module (SIM) Exception Control 7.5.2 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 configure register 1 (CONFIG1). If the SSREC bit is a logic one, then the stop recovery is reduced from the normal delay of 4096 OSCXCLK cycles down to 32 OSCXCLK cycles. This is ideal for applications using canned oscillators that do not require long start-up times from stop mode. External crystal applications should use the full stop recovery time, that is, with SSREC cleared. 7.5.3 SIM Counter and Reset States External reset has no effect on the SIM counter (see 7.7.2 Stop Mode). The SIM counter is free-running after all reset states (see 7.4.2 Active Resets from Internal Sources for counter control and internal reset recovery sequences). 7.6 Exception Control Normally, sequential program execution can be changed in three different ways: • Interrupts – Maskable hardware CPU interrupts – Non-maskable software interrupt instruction (SWI) • Reset • Break interrupts MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet System Integration Module (SIM) 97 System Integration Module (SIM) 7.6.1 Interrupts An interrupt temporarily changes the sequence of program execution to respond to a particular event. Figure 7-9 flow charts the handling of system interrupts. 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 7-7 shows interrupt entry timing. Figure 7-8 shows interrupt recovery timing. MODULE INTERRUPT I BIT IAB IDB DUMMY DUMMY SP 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 7-7. Interrupt Entry MODULE INTERRUPT I BIT IAB IDB SP – 4 SP – 3 CCR SP – 2 A SP – 1 X SP PC PC – 1[7:0] PC – 1[15:8] PC + 1 OPCODE OPERAND R/W Figure 7-8. Interrupt Recovery Data Sheet 98 MC68HC908BD48 — Rev. 2.0 System Integration Module (SIM) MOTOROLA System Integration Module (SIM) Exception Control FROM RESET BREAK INTERRUPT? I BIT SET? YES NO YES I BIT SET? NO IRQ INTERRUPT? YES NO USB INTERRUPT? YES NO STACK CPU REGISTERS. SET I BIT. LOAD PC WITH INTERRUPT VECTOR. (As many interrupts as exist on chip) FETCH NEXT INSTRUCTION. SWI INSTRUCTION? YES NO RTI INSTRUCTION? YES UNSTACK CPU REGISTERS. NO EXECUTE INSTRUCTION. Figure 7-9. Interrupt Processing MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet System Integration Module (SIM) 99 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 may take precedence, regardless of priority, until the latched interrupt is serviced (or the I bit is cleared). (See Figure 7-9. Interrupt Processing.) 7.6.1.1 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 7-10 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 LDA #$FF INT1 BACKGROUND ROUTINE PSHH INT1 INTERRUPT SERVICE ROUTINE PULH RTI INT2 PSHH INT2 INTERRUPT SERVICE ROUTINE PULH RTI Figure 7-10. Interrupt Recognition Example Data Sheet 100 MC68HC908BD48 — Rev. 2.0 System Integration Module (SIM) MOTOROLA System Integration Module (SIM) Exception Control The LDA opcode is pre-fetched by both the INT1 and INT2 RTI instructions. However, in the case of the INT1 RTI pre-fetch, 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. 7.6.1.2 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. 7.6.2 Interrupt Status Registers The flags in the interrupt status registers identify maskable interrupt sources. Table 7-4 summarizes the interrupt sources and the interrupt status register flags that they set. The interrupt status registers can be useful for debugging. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet System Integration Module (SIM) 101 System Integration Module (SIM) Table 7-4. Interrupt Sources Flag Mask1 INT Register Flag Priority2 Vector Address Reset None None None 0 $FFFE–$FFFF SWI Instruction None None None 0 $FFFC–$FFFD IRQ pin IRQF IMASK IF1 1 $FFFA–$FFFB TBEF TBIE RBFF RBIE EOPIF EOPIE IF2 2 $FFF8–$FFF9 RSTIF RSTIE TXD1F TXD1IE IF3 3 $FFF6–$FFF7 Source USB ALIF NAKIF DIEN DDC12AB RXIF TXIF SCLIF SCLIEN — — — — $FFF4–$FFF5 TIM channel 0 CH0F CH0IE IF5 5 $FFF2–$FFF3 TIM channel 1 CH1F CH1IE IF6 6 $FFF0–$FFF1 TOF TOIE IF7 7 $FFEE–$FFEF VSIF VSIE IF8 8 $FFEC–$FFED LVSIF LVSIE MMIEN IF9 9 $FFEA–FFEB COCO AIEN IF10 10 $FFE8–$FFE9 — — — — $FFE6–$FFE7 Reserved TIM overflow Sync processor MMALIF MMNAKIF Multi-master IIC MMRXIF MMTXIF ADC conversion complete Reserved 1. The I bit in the condition code register is a global mask for all interrupts sources except the SWI instruction. 2. 0 = highest priority Data Sheet 102 MC68HC908BD48 — Rev. 2.0 System Integration Module (SIM) MOTOROLA System Integration Module (SIM) Exception Control 7.6.2.1 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 7-11. Interrupt Status Register 1 (INT1) IF6–IF1 — Interrupt Flags 6–1 These flags indicate the presence of interrupt requests from the sources shown in Table 7-4. 1 = Interrupt request present 0 = No interrupt request present Bit 1and Bit 0 — Always read 0 7.6.2.2 Interrupt Status Register 2 Address: $FE05 Bit 7 6 5 4 3 2 1 Bit 0 Read: 0 0 0 0 IF10 IF9 IF8 IF7 Write: R R R R R R R R Reset: 0 0 0 0 0 0 0 0 R = Reserved Figure 7-12. Interrupt Status Register 2 (INT2) IF10–IF7 — Interrupt Flags 6–1 These flags indicate the presence of interrupt requests from the sources shown in Table 7-4. 1 = Interrupt request present 0 = No interrupt request present Bit 7 and Bit 4 — Always read 0 MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet System Integration Module (SIM) 103 System Integration Module (SIM) 7.6.3 Reset All reset sources always have equal and highest priority and cannot be arbitrated. 7.6.4 Break Interrupts The break module can stop normal program flow at a softwareprogrammable break point by asserting its break interrupt output (see Section 20. Break Module (BRK)). 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. 7.6.5 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 SIM break flag control register (SBFCR). 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 two-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. Data Sheet 104 MC68HC908BD48 — Rev. 2.0 System Integration Module (SIM) MOTOROLA System Integration Module (SIM) Low-Power Modes 7.7 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 below. Both STOP and WAIT clear the interrupt mask (I) in the condition code register, allowing interrupts to occur. 7.7.1 Wait Mode In wait mode, the CPU clocks are inactive while the peripheral clocks continue to run. Figure 7-13 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. 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 SIM break status register (SBSR). If the COP disable bit, COPD, in configuration register 1 (CONFIG1) is logic zero, then the computer operating properly module (COP) is enabled and remains active in wait mode. IAB IDB WAIT ADDR WAIT ADDR + 1 PREVIOUS DATA NEXT OPCODE SAME SAME SAME SAME R/W NOTE: Previous data can be operand data or the WAIT opcode, depending on the last instruction. Figure 7-13. Wait Mode Entry Timing Figure 7-14 and Figure 7-15 show the timing for WAIT recovery. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet System Integration Module (SIM) 105 System Integration Module (SIM) IAB IDB $6E0B $A6 $A6 $6E0C $A6 $00FF $01 $0B $00FE $00FD $00FC $6E EXITSTOPWAIT NOTE: EXITSTOPWAIT = RST pin OR CPU interrupt OR break interrupt Figure 7-14. 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 7-15. Wait Recovery from Internal Reset 7.7.2 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 configuration register 1 (CONFIG1). If SSREC is set, stop recovery is reduced from the normal delay of 4096 OSCXCLK cycles down to 32. This is ideal for applications using canned oscillators that do not require long start-up times from stop mode. NOTE: External crystal applications should use the full stop recovery time by clearing the SSREC bit. Data Sheet 106 MC68HC908BD48 — Rev. 2.0 System Integration Module (SIM) MOTOROLA System Integration Module (SIM) Low-Power Modes A break interrupt during stop mode sets the SIM break stop/wait bit (SBSW) in the SIM break status register (SBSR). 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 7-16 shows stop mode entry timing. 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 7-16. Stop Mode Entry Timing STOP RECOVERY PERIOD OSCXCLK INT/BREAK IAB STOP +1 STOP + 2 STOP + 2 SP SP – 1 SP – 2 SP – 3 Figure 7-17. Stop Mode Recovery from Interrupt or Break MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet System Integration Module (SIM) 107 System Integration Module (SIM) 7.8 SIM Registers The SIM has three memory mapped registers. Table 7-5 shows the mapping of these registers. Table 7-5. SIM Registers Summary Address Register Access Mode $FE00 SBSR User $FE01 SRSR User $FE03 SBFCR User 7.8.1 SIM Break Status Register (SBSR) The SIM 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: Bit 0 SBSW Write: Reset: 1 R Note 0 0 Note: Writing a logic 0 clears SBSW. 0 0 R = Reserved 0 0 0 0 Figure 7-18. SIM Break Status Register (SBSR) SBSW — SIM Break Stop/Wait Bit 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 Data Sheet 108 MC68HC908BD48 — Rev. 2.0 System Integration Module (SIM) MOTOROLA System Integration Module (SIM) SIM Registers SBSW can be read within the break interrupt routine. The user can modify the return address on the stack by subtracting one from it. The following code is an example. ; 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,SBSR, 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. 7.8.2 SIM Reset Status Register (SRSR) This register contains six flags that show the source of the last reset. Clear the SIM reset status register by reading it. A power-on reset sets the POR bit and clears all other bits in the register. Address: Read: $FE01 Bit 7 6 5 4 3 2 1 Bit 0 POR PIN COP ILOP ILAD 0 0 0 1 0 0 0 0 0 0 0 Write: POR: = Unimplemented Figure 7-19. SIM Reset Status Register (SRSR) POR — Power-On Reset Bit 1 = Last reset caused by POR circuit 0 = Read of SRSR MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet System Integration Module (SIM) 109 System Integration Module (SIM) PIN — External Reset Bit 1 = Last reset caused by external reset pin (RST) 0 = POR or read of SRSR COP — Computer Operating Properly Reset Bit 1 = Last reset caused by COP counter 0 = POR or read of SRSR ILOP — Illegal Opcode Reset Bit 1 = Last reset caused by an illegal opcode 0 = POR or read of SRSR ILAD — Illegal Address Reset Bit (opcode fetches only) 1 = Last reset caused by an opcode fetch from an illegal address 0 = POR or read of SRSR 7.8.3 SIM Break Flag Control Register (SBFCR) The SIM break flag 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 7-20. SIM Break Flag Control Register (SBFCR) 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 Data Sheet 110 MC68HC908BD48 — Rev. 2.0 System Integration Module (SIM) MOTOROLA Data Sheet – MC68HC908BD48 Section 8. Oscillator (OSC) 8.1 Contents 8.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111 8.3 Oscillator External Connections . . . . . . . . . . . . . . . . . . . . . . .112 8.4 I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113 8.4.1 Crystal Amplifier Input Pin (OSC1). . . . . . . . . . . . . . . . . . . 113 8.4.2 Crystal Amplifier Output Pin (OSC2) . . . . . . . . . . . . . . . . . 113 8.4.3 Oscillator Enable Signal (SIMOSCEN). . . . . . . . . . . . . . . . 113 8.4.4 External Clock Source (OSCXCLK) . . . . . . . . . . . . . . . . . . 113 8.4.5 Oscillator Out (OSCOUT). . . . . . . . . . . . . . . . . . . . . . . . . . 113 8.5 Low Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 8.5.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .114 8.5.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .114 8.6 Oscillator During Break Mode. . . . . . . . . . . . . . . . . . . . . . . . . 114 8.2 Introduction The oscillator circuit is designed for use with crystals or ceramic resonators. The oscillator circuit generates the crystal clock signal, OSCXCLK, at the frequency of the crystal. This signal is divided by two before being passed on to the SIM for bus clock generation. Figure 8-1 shows the structure of the oscillator. The oscillator requires various external components. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Oscillator (OSC) 111 Oscillator (OSC) 8.3 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 8-1. 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) 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. From SIM To SIM OSCXCLK To SIM ÷2 OSCOUT SIMOSCEN MCU OSC1 OSC2 RB RS * X1 C1 C2 *RS can be zero (shorted) when used with higher-frequency crystals. Refer to manufacturer’s data. Figure 8-1. Oscillator External Connections Data Sheet 112 MC68HC908BD48 — Rev. 2.0 Oscillator (OSC) MOTOROLA Oscillator (OSC) I/O Signals 8.4 I/O Signals The following paragraphs describe the oscillator I/O signals. 8.4.1 Crystal Amplifier Input Pin (OSC1) The OSC1 pin is an input to the crystal oscillator amplifier. An externally generated clock also can feed the OSC1 pin of the crystal oscillator circuit. Connect the external clock to the OSC1 pin and let the OSC2 pin float. 8.4.2 Crystal Amplifier Output Pin (OSC2) The OSC2 pin is the output of the crystal oscillator inverting amplifier. 8.4.3 Oscillator Enable Signal (SIMOSCEN) The SIMOSCEN signal comes from the SIM and enables the oscillator. 8.4.4 External Clock Source (OSCXCLK) OSCXCLK is the crystal oscillator output signal. It runs at the full speed of the crystal (fXCLK) and comes directly from the crystal oscillator circuit. Figure 8-1 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 start-up. 8.4.5 Oscillator Out (OSCOUT) The clock driven to the SIM is the crystal frequency divided by two. 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 fourth of the OSCXCLK frequency. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Oscillator (OSC) 113 Oscillator (OSC) 8.5 Low Power Modes The WAIT and STOP instructions put the MCU in low-powerconsumption standby modes. 8.5.1 Wait Mode The WAIT instruction has no effect on the oscillator logic. OSCXCLK continues to drive to the SIM module. 8.5.2 Stop Mode The STOP instruction disables the OSCXCLK output. 8.6 Oscillator During Break Mode The oscillator continues drive OSCXCLK when the chip enters the break state. Data Sheet 114 MC68HC908BD48 — Rev. 2.0 Oscillator (OSC) MOTOROLA Data Sheet – MC68HC908BD48 Section 9. Monitor ROM (MON) 9.1 Contents 9.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 9.3 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116 9.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .116 9.4.1 Entering Monitor Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118 9.4.2 Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119 9.4.3 Echoing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120 9.4.4 Break Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120 9.4.5 Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121 9.4.6 Baud Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .124 9.2 Introduction This section describes the monitor ROM. The monitor ROM allows complete testing of the MCU through a single-wire interface with a host computer. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Monitor ROM (MON) 115 Monitor ROM (MON) 9.3 Features Features of the monitor ROM include: • 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 • 9600 Baud communication with host computer • Execution of code in RAM or FLASH • FLASH memory programming 9.4 Functional Description The monitor ROM receives and executes commands from a host computer. Figure 9-1 shows a sample 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 all 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. Data Sheet 116 MC68HC908BD48 — Rev. 2.0 Monitor ROM (MON) MOTOROLA Monitor ROM (MON) Functional Description 68HC908BD48 VDD 10 kΩ RST 0.1 µF VSS VSS1 VDD VDD 0.1 µF OSC1 X1 9.83 MHz 20 pF 10 MΩ OSC2 MAX232 1 1 µF + 3 4 1 µF C1+ 20 pF VDD VCC C1– GND C2+ V+ 16 + 1 µF 15 1 µF + VTST 2 VDD + 5 C2– V– 6 8.5 V + VDD 1 µF 10 k 3 7 10 8 9 10 kΩ 74HC125 5 6 DB9 2 IRQ 1k 74HC125 3 2 PTA0 4 PTC3 1 5 VDD VDD 10 kΩ A (See NOTES) NOTES: 10 kΩ B PTC0 PTC1 Position A — Bus clock = OSCXCLK ÷ 4 Position B — Bus clock = OSCXCLK ÷ 2 PTA7 Figure 9-1. Monitor Mode Circuit MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Monitor ROM (MON) 117 Monitor ROM (MON) 9.4.1 Entering Monitor Mode Table 9-1 shows the pin conditions for entering monitor mode. NOTE: IRQ Pin PTC0 Pin PTC1 Pin PTA7 Pin PTA0 Pin PTC3 Pin Table 9-1. Mode Selection Mode VTST 1 0 0 1 1 Monitor OSCXCLK ---------------------------2 OSCXCLK ---------------------------4 VTST 1 0 0 1 0 Monitor OSCXCLK OSCXCLK ---------------------------2 OSCOUT Bus Frequency Holding the PTC3 pin low when entering monitor mode causes a bypass of a divide-by-two stage at the oscillator. The OSCOUT frequency is equal to the OSCXCLK frequency, and the OSC1 input directly generates internal bus clocks. In this case, the OSC1 signal must have a 50% duty cycle at maximum bus frequency. 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 monitor mode firmware then sends a break signal (10 consecutive logic zeros) to the host computer, 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. Monitor mode uses different vectors for reset and SWI. 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. When the host computer has completed downloading code into the MCU RAM, This code can be executed by driving PTA0 low while asserting RST low and then high. The internal monitor ROM firmware will interpret the low on PTA0 as an indication to jump to RAM, and execution control will then continue from RAM. Execution of an SWI from the downloaded code will return program control to the internal monitor ROM firmware. Data Sheet 118 MC68HC908BD48 — Rev. 2.0 Monitor ROM (MON) MOTOROLA Monitor ROM (MON) Functional Description Alternatively, the host can send a RUN command, which executes an RTI, and this can be used to send control to the address on the stack pointer. The COP module is disabled in monitor mode as long as VTST is applied to the IRQ or the RST pin. (See Section 7. System Integration Module (SIM) for more information on modes of operation.) Table 9-2 is a summary of the differences between user mode and monitor mode. Table 9-2. Mode Differences Functions COP Reset Vector High Reset Vector Low SWI Vector High SWI Vector Low User Enabled $FFFE $FFFF $FFFC $FFFD Monitor Disabled(1) $FEFE $FEFF $FEFC $FEFD Modes Notes: 1. If the high voltage (VTST) is removed from the IRQ 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. 9.4.2 Data Format Communication with the monitor ROM is in standard non-return-to-zero (NRZ) mark/space data format. (See Figure 9-2 and Figure 9-3.) START BIT BIT 0 BIT 1 BIT 2 BIT 3 BIT 4 BIT 5 BIT 6 BIT 7 STOP BIT NEXT START BIT Figure 9-2. 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 NEXT START BIT STOP BIT Figure 9-3. Sample Monitor Waveforms MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Monitor ROM (MON) 119 Monitor ROM (MON) The data transmit and receive rate can be anywhere from 4800 baud to 28.8 kbaud. Transmit and receive baud rates must be identical. 9.4.3 Echoing As shown in Figure 9-4, 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 ADDR. LOW DATA ECHO RESULT Figure 9-4. Read Transaction Any result of a command appears after the echo of the last byte of the command. 9.4.4 Break Signal A start bit followed by nine low bits is a break signal (see Figure 9-5). 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 9-5. Break Transaction Data Sheet 120 MC68HC908BD48 — Rev. 2.0 Monitor ROM (MON) MOTOROLA Monitor ROM (MON) Functional Description 9.4.5 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) Table 9-3. 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 ADDRESS HIGH ADDRESS HIGH ECHO ADDRESS LOW DATA RETURN MC68HC908BD48 — Rev. 2.0 MOTOROLA ADDRESS LOW Data Sheet Monitor ROM (MON) 121 Monitor ROM (MON) Table 9-4. WRITE (Write Memory) Command Description Write byte to memory Operand Specifics 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 ADDRESS HIGH ADDRESS HIGH ADDRESS LOW ADDRESS LOW DATA DATA ECHO Table 9-5. 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 ECHO Data Sheet 122 DATA DATA RETURN MC68HC908BD48 — Rev. 2.0 Monitor ROM (MON) MOTOROLA Monitor ROM (MON) Functional Description Table 9-6. 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 A sequence of IREAD or IWRITE commands can sequentially access a block of memory over the full 64-kbyte memory map. Table 9-7. 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 ECHO MC68HC908BD48 — Rev. 2.0 MOTOROLA SP HIGH SP LOW RETURN Data Sheet Monitor ROM (MON) 123 Monitor ROM (MON) Table 9-8. RUN (Run User Program) Command Description Executes RTI instruction Operand None Data Returned None Opcode $28 Command Sequence SENT TO MONITOR RUN RUN ECHO 9.4.6 Baud Rate The communication baud rate is controlled by crystal frequency and the state of the PTC3 pin upon entry into monitor mode. When PTC3 is high, the divide by ratio is 1024. If the PTC3 pin is at logic zero upon entry into monitor mode, the divide by ratio is 512. Table 9-9. Monitor Baud Rate Selection Crystal Frequency PTC3 Pin Baud Rate 19.66 MHz 0 19200 bps 9.83 MHz 0 9600 bps 9.83 MHz 1 4800 bps Data Sheet 124 MC68HC908BD48 — Rev. 2.0 Monitor ROM (MON) MOTOROLA Data Sheet – MC68HC908BD48 Section 10. Timer Interface Module (TIM) 10.1 Contents 10.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126 10.3 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126 10.4 Pin Name Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126 10.5 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .127 10.5.1 TIM Counter Prescaler . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129 10.5.2 Input Capture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129 10.5.3 Output Compare. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129 10.5.3.1 Unbuffered Output Compare . . . . . . . . . . . . . . . . . . . . . 130 10.5.3.2 Buffered Output Compare . . . . . . . . . . . . . . . . . . . . . . .131 10.5.4 Pulse Width Modulation (PWM) . . . . . . . . . . . . . . . . . . . . . 131 10.5.4.1 Unbuffered PWM Signal Generation . . . . . . . . . . . . . . . 132 10.5.4.2 Buffered PWM Signal Generation . . . . . . . . . . . . . . . . . 133 10.5.4.3 PWM Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134 10.6 Interrupts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .135 10.7 Wait Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135 10.8 TIM During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . 136 10.9 I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136 10.10 I/O Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137 10.10.1 TIM Status and Control Register (TSC) . . . . . . . . . . . . . . . 137 10.10.2 TIM Counter Registers (TCNTH:TCNTL) . . . . . . . . . . . . . . 139 10.10.3 TIM Counter Modulo Registers (TMODH:TMODL) . . . . . . 140 10.10.4 TIM Channel Status and Control Registers (TSC0:TSC1) . 141 10.10.5 TIM Channel Registers (TCH0H/L:TCH1H/L) . . . . . . . . . . 145 MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Timer Interface Module (TIM) 125 Timer Interface Module (TIM) 10.2 Introduction This section describes the timer interface module (TIM2, version B). The TIM is a two-channel timer that provides a timing reference with input capture, output compare, and pulse-width-modulation functions. Figure 10-1 is a block diagram of the TIM. 10.3 Features Features of the TIM include the following: • Two input capture/output compare channels – Rising-edge, falling-edge, or any-edge input capture trigger – Set, clear, or toggle output compare action NOTE: • Buffered and unbuffered pulse width modulation (PWM) signal generation • Programmable TIM clock input with 7-frequency internal bus clock prescaler selection • Free-running or modulo up-count operation • Toggle any channel pin on overflow • TIM counter stop and reset bits TCH1 (timer channel 1) is not bonded to an external pin on this MCU. Therefore, any references to the timer TCH1 pin in the following text should be interpreted as not available — but the internal status and control registers are still available. 10.4 Pin Name Conventions The TIM share one I/O pin with one port E I/O pin. The full name of the TIM I/O pin is listed in Table 10-1. The generic pin name appear in the text that follows. Table 10-1. Pin Name Conventions TIM Generic Pin Names: TCH0 TCH1 Full TIM Pin Names: PTE0/SOG/TCH0 Not Available Data Sheet 126 MC68HC908BD48 — Rev. 2.0 Timer Interface Module (TIM) MOTOROLA Timer Interface Module (TIM) Functional Description 10.5 Functional Description Figure 10-1 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. 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 16-BIT COMPARATOR TCH1 (Not available) TCH1H:TCH1L CH1F INTERRUPT LOGIC 16-BIT LATCH MS1A CH1IE Figure 10-1. TIM Block Diagram MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Timer Interface Module (TIM) 127 Timer Interface Module (TIM) Table 10-2. TIM I/O Register Summary Addr. Register Name TIM Status and Control Register (TSC) $000A $000C $000D TIM Counter Register High (TCNTH) TIM Counter Register Low (TCNTL) Bit 7 Read: $000E $000F $0010 $0011 $0012 $0013 TIM Counter Modulo Register Low (TMODL) TIM Channel 0 Status/Control Register (TSC0) TIM Channel 0 Register High (TCH0H) TIM Channel 0 Register Low (TCH0L) TIM Channel 1 Status/Control Register (TSC1) 5 TOIE TSTOP TOF 3 0 0 2 1 Bit 0 PS2 PS1 PS0 0 TRST Reset: 0 0 1 0 0 0 0 0 Read: Bit15 Bit14 Bit13 Bit12 Bit11 Bit10 Bit9 Bit8 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: 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 Data Sheet 128 4 Write: Reset: TIM Counter Modulo Register High (TMODH) 6 MC68HC908BD48 — Rev. 2.0 Timer Interface Module (TIM) MOTOROLA 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 10.5.1 TIM Counter Prescaler The TIM clock source can be one of the seven prescaler outputs. 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. 10.5.2 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. 10.5.3 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. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Timer Interface Module (TIM) 129 Timer Interface Module (TIM) 10.5.3.1 Unbuffered Output Compare Any output compare channel can generate unbuffered output compare pulses as described in 10.5.3 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: • 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. Data Sheet 130 MC68HC908BD48 — Rev. 2.0 Timer Interface Module (TIM) MOTOROLA Timer Interface Module (TIM) Functional Description 10.5.3.2 Buffered Output Compare Channels 0 and 1 can be linked to form a buffered output compare channel whose output appears on the 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 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, 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. 10.5.4 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 10-2 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 one. Program the TIM to set the pin if the state of the PWM pulse is logic zero. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Timer Interface Module (TIM) 131 Timer Interface Module (TIM) OVERFLOW OVERFLOW OVERFLOW PERIOD PULSE WIDTH TCHx OUTPUT COMPARE OUTPUT COMPARE OUTPUT COMPARE Figure 10-2. 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 10.10.1 TIM Status and Control Register (TSC)). 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%. 10.5.4.1 Unbuffered PWM Signal Generation Any output compare channel can generate unbuffered PWM pulses as described in 10.5.4 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. Data Sheet 132 MC68HC908BD48 — Rev. 2.0 Timer Interface Module (TIM) MOTOROLA 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. 10.5.4.2 Buffered PWM Signal Generation Channels 0 and 1 can be linked to form a buffered PWM channel whose output appears on the 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 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, TCH1, is available as a general-purpose I/O pin. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Timer Interface Module (TIM) 133 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. 10.5.4.3 PWM Initialization To ensure correct operation when generating unbuffered or buffered PWM signals, use the following 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 10-4.) 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 10-4.) 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. Data Sheet 134 MC68HC908BD48 — Rev. 2.0 Timer Interface Module (TIM) MOTOROLA 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 channel 0 status and control register (TSC0) controls and monitors the PWM signal from the linked channels. 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 10.10.4 TIM Channel Status and Control Registers (TSC0:TSC1). 10.6 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. 10.7 Wait Mode The WAIT instruction puts the MCU in low-power-consumption standby 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. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Timer Interface Module (TIM) 135 Timer Interface Module (TIM) 10.8 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 7.8.3 SIM Break Flag Control Register (SBFCR).) To allow software to clear status bits during a break interrupt, write a logic one 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 zero to the BCFE bit. With BCFE at logic zero (its default state), software can read and write I/O registers during the break state without affecting status bits. Some status bits have a two-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 zero. After the break, doing the second step clears the status bit. 10.9 I/O Signals Port E shares one of its pins with the TIM. The TIM channel I/O pin is PTE0/SOG/TCH0. TCH0 pin is programmable independently as an input capture pin or an output compare pin. It also can be configured as a buffered output compare or buffered PWM pin. Data Sheet 136 MC68HC908BD48 — Rev. 2.0 Timer Interface Module (TIM) MOTOROLA Timer Interface Module (TIM) I/O Registers 10.10 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) 10.10.1 TIM Status and Control Register (TSC) The TIM status and control register does the following: • 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 10-3. 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 zero to TOF. If another TIM overflow occurs before the MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Timer Interface Module (TIM) 137 Timer Interface Module (TIM) clearing sequence is complete, then writing logic zero 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 one 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 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 zero. 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 TCLK pin or one of the seven prescaler outputs as the input to the TIM counter as Table 10-3 shows. Reset clears the PS[2:0] bits. Data Sheet 138 MC68HC908BD48 — Rev. 2.0 Timer Interface Module (TIM) MOTOROLA Timer Interface Module (TIM) I/O Registers Table 10-3. 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 Not available 10.10.2 TIM Counter Registers (TCNTH:TCNTL) 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. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Timer Interface Module (TIM) 139 Timer Interface Module (TIM) Address: Read: $000C TCNTH Bit 7 6 5 4 3 2 1 Bit 0 Bit15 Bit14 Bit13 Bit12 Bit11 Bit10 Bit9 Bit8 0 0 0 0 0 0 0 0 $000D TCNTL Bit 7 6 5 4 3 2 1 Bit 0 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 0 0 0 0 0 0 0 0 Write: Reset: Address: Read: Write: Reset: = Unimplemented Figure 10-4. TIM Counter Registers (TCNTH:TCNTL) 10.10.3 TIM Counter Modulo Registers (TMODH:TMODL) 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. Data Sheet 140 MC68HC908BD48 — Rev. 2.0 Timer Interface Module (TIM) MOTOROLA Timer Interface Module (TIM) I/O Registers Address: $000E TMODH Bit 7 6 5 4 3 2 1 Bit 0 Bit15 Bit14 Bit13 Bit12 Bit11 Bit10 Bit9 Bit8 1 1 1 1 1 1 1 1 $000F TMODL Bit 7 6 5 4 3 2 1 Bit 0 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 1 1 1 1 1 1 1 1 Read: Write: Reset: Address: Read: Write: Reset: Figure 10-5. TIM Counter Modulo Registers (TMODH:TMODL) NOTE: Reset the TIM counter before writing to the TIM counter modulo registers. 10.10.4 TIM Channel Status and Control Registers (TSC0:TSC1) 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 MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Timer Interface Module (TIM) 141 Timer Interface Module (TIM) Address: $0010 TSC0 Bit 7 6 5 4 3 2 1 Bit 0 CH0IE MS0B MS0A ELS0B ELS0A TOV0 CH0MAX 0 0 0 0 0 0 5 4 3 2 1 Bit 0 MS1A ELS1B ELS1A TOV1 CH1MAX 0 0 0 0 0 Read: CH0F Write: 0 Reset: 0 0 $0013 TSC1 Bit 7 6 Address: Read: CH1F 0 CH1IE Write: 0 Reset: 0 0 0 = Unimplemented Figure 10-6. TIM Channel Status and Control Registers (TSC0:TSC1) 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 zero to CHxF. If another interrupt request occurs before the clearing sequence is complete, then writing logic zero 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 one 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 Data Sheet 142 MC68HC908BD48 — Rev. 2.0 Timer Interface Module (TIM) MOTOROLA Timer Interface Module (TIM) I/O Registers 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:A ≠ 00, this read/write bit selects either input capture operation or unbuffered output compare/PWM operation. See Table 10-4. 1 = Unbuffered output compare/PWM operation 0 = Input capture operation When ELSxB:A = 00, this read/write bit selects the initial output level of the TCHx pin. (See Table 10-4.). 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 an I/O port , and pin TCHx is available as a general-purpose port I/O pin. Table 10-4 shows how ELSxB and ELSxA work. Reset clears the ELSxB and ELSxA bits. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Timer Interface Module (TIM) 143 Timer Interface Module (TIM) Table 10-4. Mode, Edge, and Level Selection MSxB MSxA ELSxB ELSxA X 0 0 0 Mode Output Preset NOTE: 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 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 Before enabling a TIM channel register for input capture operation, make sure that the 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 one, setting the CHxMAX bit forces the duty cycle of buffered and unbuffered PWM signals to 100%. As Figure 10-7 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. Data Sheet 144 MC68HC908BD48 — Rev. 2.0 Timer Interface Module (TIM) MOTOROLA Timer Interface Module (TIM) I/O Registers OVERFLOW OVERFLOW OVERFLOW OVERFLOW OVERFLOW PERIOD PTDx/TCHx OUTPUT COMPARE OUTPUT COMPARE OUTPUT COMPARE OUTPUT COMPARE CHxMAX Figure 10-7. CHxMAX Latency 10.10.5 TIM Channel Registers (TCH0H/L:TCH1H/L) 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. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Timer Interface Module (TIM) 145 Timer Interface Module (TIM) Address: $0011 TCH0H Bit 7 6 5 4 3 2 1 Bit 0 Bit15 Bit14 Bit13 Bit12 Bit11 Bit10 Bit9 Bit8 Read: Write: Reset: Address: Indeterminate after reset $0012 TCH0L Bit 7 6 5 4 3 2 1 Bit 0 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 Read: Write: Reset: Address: Indeterminate after reset $0014 TCH1H Bit 7 6 5 4 3 2 1 Bit 0 Bit15 Bit14 Bit13 Bit12 Bit11 Bit10 Bit9 Bit8 Read: Write: Reset: Address: Indeterminate after reset $0015 TCH1L Bit 7 6 5 4 3 2 1 Bit 0 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 Read: Write: Reset: Indeterminate after reset Figure 10-8. TIM Channel Registers (TCH0H/L:TCH1H/L) Data Sheet 146 MC68HC908BD48 — Rev. 2.0 Timer Interface Module (TIM) MOTOROLA Data Sheet – MC68HC908BD48 Section 11. Pulse Width Modulator (PWM) 11.1 Contents 11.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147 11.3 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .147 11.4 PWM Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149 11.4.1 PWM Data Registers 0 to 15 (0PWM–15PWM). . . . . . . . . 150 11.4.2 PWM Control Registers 1 and 2 (PWMCR1:PWMCR2) . . 151 11.2 Introduction Sixteen 8-bits PWM channels are available on the MC68HC908BD48. Channels 0 to 7 are shared with port-B I/O pins under the control of the PWM control register 1. Channels 8 to 15 are shared with port-A I/O pins under the control of the PWM control register 2. 11.3 Functional Description Each 8-bit PWM channel is composed of an 8-bit register which contains a 5-bit PWM in MSB portion and a 3-bit binary rate multiplier (BRM) in LSB portion. There are 16 PWM data registers as shown in Table 11-1. The value programmed in the 5-bit PWM portion will determine the pulse length of the output. The clock to the 5-bit PWM portion is the system clock, the repetition rate of the output is hence 187.5KHz at 6MHz clock. The 3-bit BRM will generate a number of narrow pulses which are equally distributed among an 8-PWM-cycle frame. The number of pulses generated is equal to the number programmed in the 3-bit BRM portion. Examples of the waveforms are shown in Figure 11-3. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Pulse Width Modulator (PWM) 147 Pulse Width Modulator (PWM) Combining the 5-bit PWM together with the 3-bit BRM, the average duty cycle at the output will be (M+N/8)/32, where M is the content of the 5-bit PWM portion, and N is the content of the 3-bit BRM portion. Using this mechanism, a true 8-bit resolution PWM type DAC with reasonably high repetition rate can be obtained. The value of each PWM Data Register is continuously compared with the content of an internal counter to determine the state of each PWM channel output pin. Double buffering is not used in this PWM design. Table 11-1. PWM I/O Register Summary Addr. $0020 $0021 $0022 $0023 $0024 $0025 $0026 $0027 Register Name PWM0 Data Register (0PWM) Read: PWM1 Data Register (1PWM) Read: PWM2 Data Register (2PWM) Read: PWM3 Data Register (3PWM) Read: PWM4 Data Register (4PWM) Read: PWM5 Data Register (5PWM) Read: PWM6 Data Register (6PWM) Read: PWM7 Data Register (7PWM) Read: PWM Control Register 1 (PWMCR1) Read: $0028 Bit 7 6 5 4 3 2 1 Bit 0 0PWM4 0PWM3 0PWM2 0PWM1 0PWM0 0BRM2 0BRM1 0BRM0 1PWM4 1PWM3 1PWM2 1PWM1 1PWM0 1BRM2 1BRM1 1BRM0 2PWM4 2PWM3 2PWM2 2PWM1 2PWM0 2BRM2 2BRM1 2BRM0 3PWM4 3PWM3 3PWM2 3PWM1 3PWM0 3BRM2 3BRM1 3BRM0 4PWM4 4PWM3 4PWM2 4PWM1 4PWM0 4BRM2 4BRM1 4BRM0 5PWM4 5PWM3 5PWM2 5PWM1 5PWM0 5BRM2 5BRM1 5BRM0 6PWM4 6PWM3 6PWM2 6PWM1 6PWM0 6BRM2 6BRM1 6BRM0 7PWM4 7PWM3 7PWM2 7PWM1 7PWM0 7BRM2 7BRM1 7BRM0 PWM7E PWM6E PWM5E PWM4E PWM3E PWM2E PWM1E PWM0E 0 0 0 0 0 0 0 0 Write: Write: Write: Write: Write: Write: Write: Write: Write: Reset: Data Sheet 148 MC68HC908BD48 — Rev. 2.0 Pulse Width Modulator (PWM) MOTOROLA Pulse Width Modulator (PWM) PWM Registers Table 11-1. PWM I/O Register Summary $0051 $0052 $0053 $0054 $0055 $0056 $0057 $0058 PWM8 Data Register (8PWM) Read: PWM9 Data Register (9PWM) Read: PWM10 Data Register (10PWM) Read: PWM11 Data Register (11PWM) Read: PWM12 Data Register (12PWM) Read: PWM13 Data Register (13PWM) Read: PWM14 Data Register (14PWM) Read: PWM15 Data Register (15PWM) Read: PWM Control Register 2 (PWMCR2) Read: $0059 8PWM4 8PWM3 8PWM2 8PWM1 8PWM0 8BRM2 8BRM1 8BRM0 9PWM4 9PWM3 9PWM2 9PWM1 9PWM0 9BRM2 9BRM1 9BRM0 10PWM4 10PWM3 10PWM2 10PWM1 10PWM0 10BRM2 10BRM1 10BRM0 11PWM4 11PWM3 11PWM2 11PWM1 11PWM0 11BRM2 11BRM1 11BRM0 12PWM4 12PWM3 12PWM2 12PWM1 12PWM0 12BRM2 12BRM1 12BRM0 13PWM4 13PWM3 13PWM2 13PWM1 13PWM0 13BRM2 13BRM1 13BRM0 14PWM4 14PWM2 14PWM1 14PWM0 14BRM2 14BRM1 14BRM0 15PWM4 15PWM3 15PWM2 15PWM1 15PWM0 15BRM2 15BRM1 15BRM0 PWM15E PWM14E PWM13E PWM12E PWM11E PWM10E PWM9E PWM8E 0 0 Write: Write: Write: Write: Write: Write: PWM3 Write: Write: Write: Reset: 0 0 0 0 0 0 11.4 PWM Registers The PWM module uses of 18 registers for data and control functions. • 16 PWM data registers ($0020–$0027 and $0051–$0058) • 2 PWM control registers ($0028 and $0059) MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Pulse Width Modulator (PWM) 149 Pulse Width Modulator (PWM) 11.4.1 PWM Data Registers 0 to 15 (0PWM—15PWM) Address: $0020–$0027 and $0051–$0058 Bit 7 6 5 4 3 2 1 Bit 0 xPWM4 xPWM3 xPWM2 xPWM1 xPWM0 xBRM2 xBRM1 xBRM0 0 0 0 0 0 0 0 0 Read: Write: Reset: Figure 11-1. PWM Data Registers 0 to 15 (0PWM–15PWM) The output waveform of the 16 PWM channels are each configured by an 8-bit register, which contains a 5-bit PWM in MSB portion and a 3-bit binary rate multiplier (BRM) in LSB portion xPWM4–xPWM0 — PWM Bits The value programmed in the 5-bit PWM portion will determine the pulse length of the output. The clock to the 5-bit PWM portion is the system clock (CPU clock), the repetition rate of the output is hence fOP ÷ 32. Examples of PWM output waveforms are shown in Figure 11-3. xBRM2–xBRM0 — Binary Rate Multiplier Bits The 3-bit BRM will generate a number of narrow pulses which are equally distributed among an 8-PWM-cycle frame. The number of pulses generated is equal to the number programmed in the 3-bit BRM portion. Examples of PWM output waveforms are shown in Figure 11-3. Data Sheet 150 MC68HC908BD48 — Rev. 2.0 Pulse Width Modulator (PWM) MOTOROLA Pulse Width Modulator (PWM) PWM Registers 11.4.2 PWM Control Registers 1 and 2 (PWMCR1:PWMCR2) $0028 $0059 PWM Control Register 1 (PWMCR1) Read: PWM Control Register 2 (PWMCR2) Read: PWM7E PWM6E PWM5E PWM4E PWM3E PWM2E PWM1E PWM0E PWM15E PWM14E PWM13E PWM12E PWM11E PWM10E PWM9E PWM8E 0 0 Write: Write: Reset: 0 0 0 0 0 0 Figure 11-2. PWM Control Register 1 and 2 (PWMCR1:PWMCR2) PWM15E–PWM0E — PWM Output Enable Setting a bit to 1 will enable the corresponding PWM channel to use as PWM output. A zero configures the corresponding PWM pin as a standard I/O port pin. Reset clears these bits. 1 = Port pin configured as PWM output 0 = Port pin configured as standard I/O port pin. Table 11-2. PWM Channels and Port I/O pins Port Pin PWM Channel Control Bit Port Pin PWM Channel Control Bit PTB0 PWM0 PWM0E PTA0 PWM8 PWM8E PTB1 PWM1 PWM1E PTA1 PWM9 PWM9E PTB2 PWM2 PWM2E PTA2 PWM10 PWM10E PTB3 PWM3 PWM3E PTA3 PWM11 PWM11E PTB4 PWM4 PWM4E PTA4 PWM12 PWM12E PTB5 PWM5 PWM5E PTA5 PWM13 PWM13E PTB6 PWM6 PWM6E PTA6 PWM14 PWM14E PTB7 PWM7 PWM7E PTA7 PWM15 PWM15E MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Pulse Width Modulator (PWM) 151 Pulse Width Modulator (PWM) 1 PWM cycle = 32T M=$00 T M=$01 31T 16T M=$0F 16T 31T M=$1F Pulse inserted at end of PWM cycle depends on setting of N. T T=1 CPU clock period (0.167µs if CPU clock=6MHz) M = value set in 5-bit PWM (bit3-bit7) N = value set in 3-bit BRM (bit0-bit2) N xx1 x1x 1xx PWM cycles where pulses are Number of inserted pulses inserted in a 8-cycle frame in a 8-cycle frame 4 1 2, 6 2 1, 3, 5, 7 4 Figure 11-3. 8-Bit PWM Output Waveforms Data Sheet 152 MC68HC908BD48 — Rev. 2.0 Pulse Width Modulator (PWM) MOTOROLA Data Sheet – MC68HC908BD48 Section 12. Analog-to-Digital Converter (ADC) 12.1 Contents 12.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153 12.3 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154 12.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .154 12.4.1 ADC Port I/O Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155 12.4.2 Voltage Conversion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .156 12.4.3 Conversion Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156 12.4.4 Continuous Conversion . . . . . . . . . . . . . . . . . . . . . . . . . . . 156 12.4.5 Accuracy and Precision . . . . . . . . . . . . . . . . . . . . . . . . . . . 157 12.5 Interrupts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .157 12.6 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157 12.6.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .157 12.6.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .157 12.7 I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157 12.7.1 ADC Voltage In (ADCVIN) . . . . . . . . . . . . . . . . . . . . . . . . . 158 12.8 I/O Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158 12.8.1 ADC Status and Control Register. . . . . . . . . . . . . . . . . . . .158 12.8.2 ADC Data Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160 12.8.3 ADC Input Clock Register . . . . . . . . . . . . . . . . . . . . . . . . . 161 12.2 Introduction This section describes the analog-to-digital converter (ADC). The ADC is an 8-bit 6-channels analog-to-digital converter. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Analog-to-Digital Converter (ADC) 153 Analog-to-Digital Converter (ADC) 12.3 Features Features of the ADC module include: • 6 Channels ADC with Multiplexed Input • Linear Successive Approximation • 8-Bit Resolution • Single or Continuous Conversion • Conversion Complete Flag or Conversion Complete Interrupt • Selectable ADC Clock Table 12-1. ADC Register Summary Addr. Register Name $005D ADC Status and Control Register (ADSCR) $005E ADC Data Register (ADR) Bit 7 Read: 6 5 4 3 2 1 Bit 0 AIEN ADCO ADCH4 ADCH3 ADCH2 ADCH1 ADCH0 COCO Write: Reset: 0 0 0 1 1 1 1 1 Read: AD7 AD6 AD5 AD4 AD3 AD2 AD1 AD0 Write: Reset: $005F ADC Input Clock Register (ADICLK) Indeterminate after Reset Read: ADIV2 ADIV1 ADIV0 0 0 0 0 0 0 0 0 0 0 0 0 0 Write: Reset: = Unimplemented 12.4 Functional Description Six ADC channels are available for sampling external sources at pins PTC5–PTC0. An analog multiplexer allows the single ADC converter to select one of the 6 ADC channels as ADC voltage input (ADCVIN). ADCVIN is converted by the successive approximation register-based counters. The ADC resolution is 8 bits. When the conversion is completed, ADC puts the result in the ADC data register and sets a flag or generates an interrupt. Figure 12-1 shows a block diagram of the ADC. Data Sheet 154 MC68HC908BD48 — Rev. 2.0 Analog-to-Digital Converter (ADC) MOTOROLA Analog-to-Digital Converter (ADC) Functional Description INTERNAL DATA BUS READ DDRC DISABLE WRITE DDRC DDRCx RESET WRITE PTC PTCx/ADCx PTCx READ PTC DISABLE ADC CHANNEL x ADC DATA REGISTER INTERRUPT LOGIC AIEN CONVERSION COMPLETE ADC ADC VOLTAGE IN ADCVIN CHANNEL SELECT (1 OF 6 CHANNELS) ADCH[4:0] ADC CLOCK COCO CLOCK GENERATOR BUS CLOCK ADIV[2:0] Figure 12-1. ADC Block Diagram 12.4.1 ADC Port I/O Pins PTC5–PTC0 are general-purpose I/O pins that are shared with the ADC channels. The channel select bits (ADC status control register, $005D), define which ADC channel/port pin will be used as the input signal. The ADC overrides the port I/O logic by forcing that pin as input to the ADC. The remaining ADC channels/port pins are controlled by the port I/O logic and can be used as general-purpose I/O. Writes to the port register MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Analog-to-Digital Converter (ADC) 155 Analog-to-Digital Converter (ADC) or DDR will not have any affect on the port pin that is selected by the ADC. Read of a port pin which is in use by the ADC will return an unknown state if the corresponding DDR bit is at logic 0. If the DDR bit is at logic 1, the value in the port data latch is read. 12.4.2 Voltage Conversion 2 When the input voltage to the ADC equals ------ VDD, the ADC converts the 3 signal to $FF (full scale). If the input voltage equals VSS, the ADC 2 converts it to $00. Input voltage between ------ VDD and VSS are a 3 straight-line linear conversion. All other input voltages will result in $FF 2 if greater than ------ VDD and $00 if less than VSS. 3 NOTE: Input voltage should not exceed the analog supply voltages. 12.4.3 Conversion Time Twelve ADC internal clocks are required to perform one conversion. The ADC starts a conversion on the first rising edge of the ADC internal clock immediately following a write to the ADSCR. If the ADC internal clock is selected to run at 1MHz, then one conversion will take 12µs to complete. With a 1MHz ADC internal clock the maximum sample rate is 83.3kHz. Conversion Time = 12 ADC Clock Cycles ADC Clock Frequency Number of Bus Cycles = Conversion Time × Bus Frequency 12.4.4 Continuous Conversion In the continuous conversion mode, the ADC continuously converts the selected channel filling the ADC data register with new data after each conversion. Data from the previous conversion will be overwritten whether that data has been read or not. Conversions will continue until the ADCO bit is cleared. The COCO bit (ADC status control register, $005D) is set after each conversion and can be cleared by writing the ADC status and control register or reading of the ADC data register. Data Sheet 156 MC68HC908BD48 — Rev. 2.0 Analog-to-Digital Converter (ADC) MOTOROLA Analog-to-Digital Converter (ADC) Interrupts 12.4.5 Accuracy and Precision The conversion process is monotonic and has no missing codes. 12.5 Interrupts When the AIEN bit is set, the ADC module is capable of generating a CPU interrupt after each ADC conversion. A CPU interrupt is generated if the COCO bit is at logic 0. The COCO bit is not used as a conversion complete flag when interrupts are enabled. 12.6 Low-Power Modes The following subsections describe the low-power modes. 12.6.1 Wait Mode The ADC continues normal operation during wait mode. Any enabled CPU interrupt request from the ADC can bring the MCU out of wait mode. If the ADC is not required to bring the MCU out of wait mode, power down the ADC by setting the ADCH[4:0] bits in the ADC status and control register to logic 1’s before executing the WAIT instruction. 12.6.2 Stop Mode The ADC module is inactive after the execution of a STOP instruction. Any pending conversion is aborted. ADC conversions resume when the MCU exits stop mode. Allow one conversion cycle to stabilize the analog circuitry before attempting a new ADC conversion after exiting stop mode. 12.7 I/O Signals The ADC module has 6 channels that are shared with I/O port C. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Analog-to-Digital Converter (ADC) 157 Analog-to-Digital Converter (ADC) 12.7.1 ADC Voltage In (ADCVIN) ADCVIN is the input voltage signal from one of the 6 ADC channels to the ADC module. 12.8 I/O Registers Three I/O registers control and monitor ADC operation: • ADC status and control register (ADSCR, $005D) • ADC data register (ADR, $005E) • ADC clock register (ADICLK, $005F) 12.8.1 ADC Status and Control Register The following paragraphs describe the function of the ADC status and control register. Address: $005D Bit 7 Read: 6 5 4 3 2 1 Bit 0 AIEN ADCO ADCH4 ADCH3 ADCH2 ADCH1 ADCH0 0 0 1 1 1 1 1 COCO Write: Reset: 0 = Unimplemented Figure 12-2. ADC Status and Control Register (ADSCR) COCO — Conversions Complete Bit When the AIEN bit is a logic 0, the COCO is a read-only bit which is set each time a conversion is completed. This bit is cleared whenever the ADC status and control register is written or whenever the ADC data register is read. Reset clears this bit. 1 = conversion completed (AIEN = 0) 0 = conversion not completed (AIEN = 0) When the AIEN bit is a logic 1 (CPU interrupt enabled), the COCO is a read-only bit, and will always be logic 0 when read. Data Sheet 158 MC68HC908BD48 — Rev. 2.0 Analog-to-Digital Converter (ADC) MOTOROLA Analog-to-Digital Converter (ADC) I/O Registers AIEN — ADC Interrupt Enable Bit When this bit is set, an interrupt is generated at the end of an ADC conversion. The interrupt signal is cleared when the data register is read or the status/control register is written. Reset clears the AIEN bit. 1 = ADC interrupt enabled 0 = ADC interrupt disabled ADCO — ADC Continuous Conversion Bit When set, the ADC will convert samples continuously and update the ADR register at the end of each conversion. Only one conversion is allowed when this bit is cleared. Reset clears the ADCO bit. 1 = Continuous ADC conversion 0 = One ADC conversion ADCH[4:0] — ADC Channel Select Bits ADCH[4:0] form a 5-bit field which is used to select one of the ADC channels. The five channel select bits are detailed in the following table. Care should be taken when using a port pin as both an analog and a digital input simultaneously to prevent switching noise from corrupting the analog signal. (See Table 12-2.) The ADC subsystem is turned off when the channel select bits are all set to one. This feature allows for reduced power consumption for the MCU when the ADC is not used. Reset sets all of these bits to a logic 1. NOTE: Recovery from the disabled state requires one conversion cycle to stabilize. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Analog-to-Digital Converter (ADC) 159 Analog-to-Digital Converter (ADC) Table 12-2. MUX Channel Select ADCH4 ADCH3 ADCH2 ADCH1 ADCH0 ADC Channel Input Select 0 0 0 0 0 ADC0 PTC0 0 0 0 0 1 ADC1 PTC1 0 0 0 1 0 ADC2 PTC2 0 0 0 1 1 ADC3 PTC3 0 0 1 0 0 ADC4 PTC4 0 0 1 0 1 ADC5 PTC5 0 0 1 1 0 : : : : : — Unused (see Note 1) 1 1 0 1 0 1 1 0 1 1 — Reserved 1 1 1 0 0 — Unused 1 1 1 0 1 VDDA (see Note 2) 1 1 1 1 0 VSSA (see Note 2) 1 1 1 1 1 ADC power off NOTES: 1. If any unused channels are selected, the resulting ADC conversion will be unknown. 2. The voltage levels supplied from internal reference nodes as specified in the table are used to verify the operation of the ADC converter both in production test and for user applications. 12.8.2 ADC Data Register One 8-bit result register is provided. This register is updated each time an ADC conversion completes. Address: Read: $005E Bit 7 6 5 4 3 2 1 Bit 0 AD7 AD6 AD5 AD4 AD3 AD2 AD1 AD0 Write: Reset: Indeterminate after Reset = Unimplemented Figure 12-3. ADC Data Register (ADR) Data Sheet 160 MC68HC908BD48 — Rev. 2.0 Analog-to-Digital Converter (ADC) MOTOROLA Analog-to-Digital Converter (ADC) I/O Registers 12.8.3 ADC Input Clock Register This register selects the clock frequency for the ADC. Address: $005F Bit 7 6 5 ADIV2 ADIV1 ADIV0 0 0 0 Read: 4 3 2 1 Bit 0 0 0 0 0 0 0 0 0 0 0 Write: Reset: = Unimplemented Figure 12-4. ADC Input Clock Register (ADICLK) ADIV2:ADIV0 — ADC Clock Prescaler Bits ADIV2, ADIV1, and ADIV0 form a 3-bit field which selects the divide ratio used by the ADC to generate the internal ADC clock. Table 12-3 shows the available clock configurations. The ADC clock should be set to approximately 1MHz. With an internal bus frequency of 6MHz, set ADIV[2:0] = 010, for a divide by four ADC clock rate. Table 12-3. ADC Clock Divide Ratio ADIV2 ADIV1 ADIV0 ADC Clock Rate 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 X X Internal bus clock ÷ 16 X = don’t care MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Analog-to-Digital Converter (ADC) 161 Analog-to-Digital Converter (ADC) Data Sheet 162 MC68HC908BD48 — Rev. 2.0 Analog-to-Digital Converter (ADC) MOTOROLA Data Sheet – MC68HC908BD48 Section 13. Universal Serial Bus Module (USB) 13.1 Contents 13.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163 13.3 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164 13.4 I/O Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164 13.5 Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .165 13.5.1 USB Address Register (UADR) . . . . . . . . . . . . . . . . . . . . . 166 13.5.2 USB Interrupt Register (UINTR). . . . . . . . . . . . . . . . . . . . . 166 13.5.3 USB Interrupt Register 1 (UIR1). . . . . . . . . . . . . . . . . . . . . 169 13.5.4 USB Control Register 0 (UCR0). . . . . . . . . . . . . . . . . . . . . 171 13.5.5 USB Control Register 1 (UCR1). . . . . . . . . . . . . . . . . . . . . 172 13.5.6 USB Control Register 2 (UCR2). . . . . . . . . . . . . . . . . . . . . 174 13.5.7 USB Status Register (USR) . . . . . . . . . . . . . . . . . . . . . . . . 175 13.5.8 USB Endpoint 0 Data Registers 0 to 7 (UD0R0–UD0R7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177 13.5.9 USB Endpoint 1/2 Data Registers 0 to 7 (UD1R0–UD1R7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177 13.2 Introduction This USB module is designed to serve as a low-speed (LS) USB device per the Universal Serial Bus Specification Rev 1.0. Three types of USB data transfers are supported: control, interrupt, and bulk (transmit only). Endpoint 0 functions as a receive/transmit control endpoint. Endpoints 1 and 2 can function as interrupt or bulk, but only in transmit direction. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Universal Serial Bus Module (USB) 163 Universal Serial Bus Module (USB) 13.3 Features Features of the USB (universal serial bus) module include the following: • Integrated 3.3-volt regulator with 3.3-volt output pin • Integrated USB transceiver supporting low-speed functions • USB data control logic – Packet decoding/generation – CRC (cyclic redundancy check) generation and checking – NRZI (non-return-to zero inserted) encoding/decoding – Bit-stuffing • USB reset support • Control endpoint 0 and interrupt endpoints 1 and 2 • Two 8-byte transmit buffers • One 8-byte receive buffer • Suspend and resume operations – Remote wakeup support • USB generated interrupts – Transaction interrupt driven – Resume interrupt – End-of-pack (EOP) interrupt • STALL, NAK, and ACK handshake generation 13.4 I/O Pins The USB module uses two I/O pins, shared with standard port I/O pins. The full name of the USB I/O pins are listed in Table 13-1. The generic pin name appear in the text that follows. Table 13-1. Pin Name Conventions USB Generic Pin Names: Full MCU Pin Names: Pin Selected for USB Function By: D+ PTD0/D+ USBD+E bit in PDCR ($0049) D– PTD1/D– USBD–E bit in PDCR ($0049) Data Sheet 164 MC68HC908BD48 — Rev. 2.0 Universal Serial Bus Module (USB) MOTOROLA Universal Serial Bus Module (USB) Registers Table 13-2. USB I/O Register Summary Addr. $0029 $002A $002B $002C $002D $002E Register Name Bit 7 5 4 3 2 1 Bit 0 UADD6 UADD5 UADD4 UADD3 UADD2 UADD1 UADD0 0 0 0 0 0 0 0 TBEF RBFF EOPIF RSTIF TBIE RBIE EOPIE RSTIE 0 0 0 0 0 0 0 0 T0SEQ STALL0 TX0E RX0E TP0SIZ3 TP0SIZ2 TP0SIZ1 TP0SIZ0 0 0 0 0 0 0 0 0 RSEQ SETUP TX1ST 0 RPSIZ3 RPSIZ2 RPSIZ1 RPSIZ0 STALL2 STALL1 Read: USBEN USB Address Register Write: (UADR) Reset: 0 Read: USB Interrupt Register Write: (UINTR) Reset: Read: USB Control Register 0 Write: (UCR0) Reset: Read: USB Status Register Write: (USR) Reset: Indeterminate after reset Read: USB Control Register 2 Write: (UCR2) Reset: 0 0 0 0 Read: USB Interrupt Register 1 (UIR1) Write: TXD1F Reset: $002F 6 Read: USB Control Register 1 Write: (UCR1) Reset: TXD1IE PULLEN SUSPND ENABLE2 ENABLE1 0 0 0 0 0 0 RESUMF 0 0 0 0 0 RESUMFR TBEFR RBFFR TXD1FR EOPFR 0 0 0 0 0 TP1SIZ2 TP1SIZ1 TP1SIZ0 0 0 0 0 0 0 T1SEQ ENDADD TX1E 0 0 0 FRESUM TP1SIZ3 0 0 $0030 to $0037 Read: UE0RDx7 UE0RDx6 UE0RDx5 UE0RDx4 UE0RDx3 UE0RDx2 UE0RDx1 UE0RDx0 USB Endpoint 0 Data Register 0–7 Write: UE0TDx7 UE0TDx6 UE0TDx5 UE0TDx4 UE0TDx3 UE0TDx2 UE0TDx1 UE0TDx0 (UD0R0–UD0R7) Reset: Indeterminate after reset $0038 to $003F Read: USB Endpoint 1/2 Data Register 0–7 Write: UE1TDx7 UE1TDx6 UE1TDx5 UE1TDx4 UE1TDx3 UE1TDx2 UE1TDx1 UE1TDx0 (UD1R0–UD1R7) Indeterminate after reset Reset: 13.5 Registers There are seven control/status registers and 24 data buffers in the USB module. These registers are discussed in the following paragraphs. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Universal Serial Bus Module (USB) 165 Universal Serial Bus Module (USB) 13.5.1 USB Address Register (UADR) Address: $0029 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: Figure 13-1. USB Address Register (UADR) USBEN — USB Enable This read/write bit enables/disables the USB module. When USBEN bit is clear, USB will not respond to any tokens, but still can detect USB reset signal, or EOP signals, and non-IDLE state if in Suspend Mode. Reset clears this bit. After USB reset, software will set this bit to enable USB. 1 = USB module enabled 0 = USB module disabled UADD[6:0] — USB Address These bits specify the USB address of the device. Reset clears these bits to $00, the default address. 13.5.2 USB Interrupt Register (UINTR) Address: Read: $002A Bit 7 6 5 4 TBEF RBFF EOPIF RSTIF 3 2 1 Bit 0 TBIE RBIE EORIE RSTIE 0 0 0 0 Write: Reset: 0 0 0 0 = Unimplemented Figure 13-2. USB Interrupt Register (UINTR) Data Sheet 166 MC68HC908BD48 — Rev. 2.0 Universal Serial Bus Module (USB) MOTOROLA Universal Serial Bus Module (USB) Registers TBEF — Transmit Buffer Empty Flag This flag is set after the data stored in endpoint 0 transmit buffer has been sent and ACK handshake packet is received. Software must clear this flag by writing a logic "1" to TBEFR bit after the data is ready in the transmit buffer. This enables the next data packet transmission when endpoint 0 transmit is enabled (TX0E = 1). TBEF generates an interrupt request to the CPU if the TBIE bit is also set. Reset clears this bit. 1 = Transmit on endpoint 0 has occurred 0 = Transmit on endpoint 0 has not occurred RBFF — Receive Buffer Full Flag This flag is set when the module has received one data packet and replied with ACK handshake packet. Software must clear this flag by writing "1" to RBFFR bit after all the received data have been read to enable the next data packet reception. RBFF generates an interrupt request to the CPU if the RBIE bit is also set. Reset clears this bit. 1 = Receive on endpoint 0 has occurred 0 = Receive on endpoint 0 has not occurred EOPIF — End Of Packet Interrupt Flag This flag is set when a valid EOP signal transition is detected on the D+ and D– lines. This flag can be cleared by writing "1" to EOPIFR bit. EOPIF generates an interrupt request to the CPU if the EOPIE bit is also set. Reset clears this bit. 1 = End-of-packet sequence has been detected 0 = End-of-packet sequence has not been detected RSTIF — Reset Interrupt Flag The flag is set when a valid reset signal state is detected on the D+ and D– lines. This flag can be cleared by writing "1" to RSTIFR bit. RSTIF generates an interrupt request to the CPU if the RSTIE bit is also set. Reset clears this bit. 1 = USB reset condition has been detected 0 = USB reset condition has not been detected MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Universal Serial Bus Module (USB) 167 Universal Serial Bus Module (USB) TBIE — Transmit Buffer Interrupt Enable When this bit is set, the TBEF flag is enabled to generate an interrupt request to the CPU. When TBIE is cleared, the TBEF flag is prevented from generating an interrupt request to the CPU. Reset clears this bit. 1 = TBEF bit set will generate interrupt request to CPU 0 = TBEF bit set does not generate interrupt request to CPU RBIE — Receive Buffer Interrupt Enable When this bit is set, the RBFF flag is enabled to generate an interrupt request to the CPU. When RBIE is cleared, the RBFF flag is prevented from generating an interrupt request to the CPU. Reset clears this bit. 1 = RBFF bit set will generate interrupt request to CPU 0 = RBFF bit set does not generate interrupt request to CPU EOPIE — End Of Packet Interrupt Enable When this bit is set, the EOPIF flag is enabled to generate an interrupt request to the CPU. When EOPIE is cleared, the EOPIF flag is prevented from generating an interrupt request to the CPU. Reset clears this bit. 1 = EOPIF bit set will generate interrupt request to CPU 0 = EOPIF bit set does not generate interrupt request to CPU RSTIE —þReset Interrupt Enable When this bit is set, the RSTIF flag is enabled to generate an interrupt request to the CPU. When RSTIE is cleared, the RSTIF flag is prevented from generating an interrupt request to the CPU. Reset clears this bit. 1 = RSTIF bit set will generate interrupt request to CPU 0 = RSTIF bit set does not generate interrupt request to CPU NOTE: Since there are more than one interrupt flags in the register, it is possible that program use Read-Modify-Write instruction to clear one flag, will occasionally clear the other flags which was just set after Read cycle of Read-Modify-Write operation. Data Sheet 168 MC68HC908BD48 — Rev. 2.0 Universal Serial Bus Module (USB) MOTOROLA Universal Serial Bus Module (USB) Registers 13.5.3 USB Interrupt Register 1 (UIR1) Address: $002E Bit 7 Read: 6 TXD1F 5 4 3 2 1 Bit 0 RESUMF 0 0 0 0 0 0 RESUMFR TBEFR RBFFR TXD1FR EOPFR 0 0 0 0 0 0 TXD1IE Write: 0 Reset: 0 0 Figure 13-3. USB Interrupt Register 1 (UIR1) TXD1F — Endpoint 1/2 Data Buffer Transmit Flag The flag is set after the data stored in endpoint 1/2 transmit buffer has been sent and ACK handshake packet from host is received. Software must clear this flag by writing a logic 1 to TXD1FR bit after the data is ready in the transmit buffer to enable the next data packet transmission when TX1E is enabled. Reset clears this bit. 1 = Transmit on endpoint 1/2 has occurred 0 = Transmit on endpoint 1/2 has not occurred TXD1IE — Transmit Buffer Interrupt Enable When this bit is set, the TXD1F flag is enabled to generate an interrupt request to the CPU. When TXD1IE is cleared, the TXD1F flag is prevented from generating an interrupt request to the CPU. Reset clears this bit. 1 = TXD1F bit set will generate interrupt request to CPU 0 = TXD1F bit set does not generate interrupt request to CPU RESUMF — Resume Flag This flag is set if the transaction from idle state to non-idle state is detected while in suspend mode (SUSPND = 1). An interrupt will be generated to wake up CPU to indicate a resume signalling from host and software will clear SUSPND bit and exit from suspend mode. USB reset signals cannot be detected while in suspend mode until SUSPND bit is cleared. The RESUMF interrupt service routine is generated by SE0 to wake up the USB module. This bit can be cleared by writing "1" to RESUMFR bit. Reset clears this bit. 1 = USB bus activity detected while in suspend mode 0 = If in suspend mode, no USB bus activity has been detected MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Universal Serial Bus Module (USB) 169 Universal Serial Bus Module (USB) RESUMFR — Resume Flag Clear Writing a logic "1" to this bit clears the RESUMF flag. Writing a "0" has no effect. Reset clears this bit. 1 = Writing 1 clears RESUMFR 0 = No effect TBEFR — Transmit Buffer Empty Flag Clear Writing a logic "1" to this bit clears the TBEF flag. Writing a "0" has no effect. Reset clears this bit. 1 = Writing 1 clears TBEF 0 = No effect RBFFR — Receive Buffer Full Flag Clear Writing a logic "1" to this bit clears the RBFF flag. Writing a "0" has no effect. Reset clears this bit. 1 = Writing 1 clears RBFF 0 = No effect TXD1FR — Endpoint 1 and 2 Data Buffer Transmit Flag Clear Writing a logic "1" to this bit clears the TXD1F flag. Writing a "0" has no effect. Reset clears this bit. 1 = Writing 1 clears TXD1F 0 = No effect EOPIFR — End Of Packet Interrupt Flag Clear Writing a logic "1" to this bit clears the EOPIF flag. Writing a "0" has no effect. Reset clears this bit. 1 = Writing 1 clears EOPIF 0 = No effect Data Sheet 170 MC68HC908BD48 — Rev. 2.0 Universal Serial Bus Module (USB) MOTOROLA Universal Serial Bus Module (USB) Registers 13.5.4 USB Control Register 0 (UCR0) Address: $002B Bit 7 6 5 4 3 2 1 Bit 0 T0SEQ STALL0 TX0E RX0E TP0SIZ3 TP0SIZ2 TP0SIZ1 TP0SIZ0 0 0 0 0 0 0 0 0 Read: Write: Reset: Figure 13-4. USB Control Register 0 (UCR0) T0SEQ — Endpoint 0 Data Packet PID Select This bit will determine the transmit data packet PID of endpoint 0. When it is "0", the DATA0 PID (b0011) will be sent. When it is "1", the DATA1 PID (b1011) will be sent. Reset clears this bit. 1 = DATA1 PID will be sent on endpoint 0 0 = DATA0 PID will be sent on endpoint 0 STALL0 — Endpoint 0 STALL Handshake This bit is set to generate the STALL handshake packet as next IN or OUT transactions handshake packet from endpoint 0. The USB hardware clears the STALL0 bit when a SETUP packet is received. Reset clears this bit. 1 = Send STALL handshake on endpoint 0 0 = Do not send STALL handshake on endpoint 0 TX0E — Endpoint 0 Transmit Enable This bit is set to enable data packet transmission from endpoint 0. Software should set this bit when data is ready for data packet transmission. It must be cleared when no more data needs to be transmitted. If TX0E is "0" or TXD0F is "1", a NAK handshake will be returned for the next IN token. Reset clears this bit. 1 = Data is ready to be sent on endpoint 0 0 = Data is not ready; respond with ACK MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Universal Serial Bus Module (USB) 171 Universal Serial Bus Module (USB) RX0E — Endpoint 0 Receive Enable This bit is set to enable data packet reception from endpoint 0. Software should set this bit when it is ready for data packet reception. It must be cleared when data cannot be received. If RX0E "0" or RBFF is "1", a NAK handshake will be returned for the next OUT token. Reset clears this bit. 1 = Data is read to be received on endpoint 0 0 = Not ready for data; respond with NAK TP0SIZ[3:0] — Endpoint 0 Transmit Data Size The TP0SIZ[3:0] is used to store the number of transmit data bytes from endpoint 0. The default size of transmit data is "0" after reset. 13.5.5 USB Control Register 1 (UCR1) Address: $002F Bit 7 6 5 T1SEQ ENDADD TX1E 0 0 0 4 3 2 1 Bit 0 TP1SIZ2 TP1SIZ1 TP1SIZ0 0 0 0 Read: FRESUM TP1SIZ3 Write: Reset: 0 0 Figure 13-5. USB Control Register 1 (UCR1) T1SEQ — Endpoint 1/2 Data Packet PID Select This bit will determine the transmit data packet PID of endpoint 1/2. When it is "0", the DATA0 PID (b0011) will be sent. When it is "1", the DATA1 PID (b1011) will be sent. Reset clears this bit. 1 = DATA1 PID will be sent on endpoint 1/2 0 = DATA0 PID will be sent on endpoint 1/2 ENDADD — Endpoint Address Select This bit specifies the which endpoint (1 or 2) uses the eight data registers, UD1R0–UD1R7, for data transmit buffers. Clearing this bit selects endpoint 1 to use the data registers. Setting this bit selects endpoint 2 to use the data registers. Data Sheet 172 MC68HC908BD48 — Rev. 2.0 Universal Serial Bus Module (USB) MOTOROLA Universal Serial Bus Module (USB) Registers If all the conditions for a successful endpoint 2 USB response to a host’s IN token are satisfied (TXD1F = 0, TX1E = 1, STALL2 = 0, ENABLE2 = 1), but endpoint 1 is selected (ENDADD = 0), the module will respond with an NAK handshake packet. Reset clears this bit. 1 = The transmit buffer is used for endpoint 2 0 = The transmit buffer is used for endpoint 1 TX1E — Endpoint 1/2 Transmit Enable This bit is set to enable data packet transmission from endpoint 1/2. Software should set this bit when data is ready for data packet transmission. It must be cleared when no more data needs to be transmitted. If TX1E is "0" or TXD1F is "1", a NAK handshake will be returned for the next IN token. Reset clears this bit. 1 = Data is ready to be sent on endpoint 1/2 0 = Data is not ready; respond with ACK FRESUM — Force Resume This bit is set to force a resume state on USB bus lines until software clears this bit. Before setting the FRESUM bit, the SUSPND bit must to be cleared in order to drive the USB bus lines. Setting the FRESUM bit will not cause RESUMF to be set. Reset clears this bit. 1 = Resume state forced on USB bus; only if SUSPND is cleared 0 = No effect TP1SIZ[3:0] — Endpoint 1/2 Transmit Data Size The TP1SIZ[3:0] is used to store the number of transmit data bytes from endpoint 1/2. The default size of transmit data is "0" after reset. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Universal Serial Bus Module (USB) 173 Universal Serial Bus Module (USB) 13.5.6 USB Control Register 2 (UCR2) Address: Read: $002D Bit 7 6 0 0 5 PULLEN Write: RSTIFR Reset: 0 4 3 2 SUSPND ENABLE2 ENABLE1 1 Bit 0 STALL2 STALL1 0 0 TX1STR 0 0 0 0 0 Figure 13-6. USB Control Register 2 (UCR2) RSTIFR — Reset Interrupt Flag Clear Writing a logic "1" to this bit clears the RSTIFR flag. Writing a "0" has no effect. Reset clears this bit. 1 = Writing 1 clears RSTIFR 0 = No effect TX1STR — TX1ST Clear Writing a logic "1" to this bit clears the TX1STR flag. Writing a "0" has no effect. Reset clears this bit. 1 = Writing 1 clears TX1STR 0 = No effect PULLEN — Pullup Enable on D– This bit is set to enable the internal 1.5kΩ pullup resister connected between the USB D– line and 3.3V. Reset clears this bit. 1 = Enable 1.5kΩ pullup resistor between D– and 3.3V 0 = Disable 1.5kΩ pullup resistor between D– and 3.3V SUSPND — USB Suspend If the 3ms constant idle state is detected on the USB bus, user software should set this bit to allow the USB module to enter suspend mode. In the suspend mode, the clock to USB module will be stopped, and other unnecessary analog circuitry will be powered down. When a resume is detected (RESUMF = 1), user software must clear SUSPND in the interrupt service routine. 1 = Enable USB suspend mode 0 = Disable USB suspend mode Data Sheet 174 MC68HC908BD48 — Rev. 2.0 Universal Serial Bus Module (USB) MOTOROLA Universal Serial Bus Module (USB) Registers ENABLE2 — Endpoint 2 Enable This bit is set to enable endpoint 2 to respond to addressed IN packet tokens. Reset clears this bit. 1 = Endpoint 2 enabled; and responds to IN tokens 0 = Endpoint 2 disabled ENABLE1 — Endpoint 1 Enable This bit is set to enable endpoint 1 to respond to addressed IN packet tokens. Reset clears this bit. 1 = Endpoint 1 enabled; and responds to IN tokens 0 = Endpoint 1 disabled STALL2 — Endpoint 2 STALL Handshake This bit is set to generate the STALL handshake packet as next IN transaction handshake packet from endpoint 2. Reset clears this bit. 1 = Send STALL handshake on endpoint 2 0 = Do not send STALL handshake on endpoint 2 STALL1 — Endpoint 1 STALL Handshake This bit is set to generate the STALL handshake packet as next IN transaction handshake packet from endpoint 1. Reset clears this bit. 1 = Send STALL handshake on endpoint 1 0 = Do not send STALL handshake on endpoint 1 13.5.7 USB Status Register (USR) Address: Read: $002C Bit 7 6 5 4 3 2 1 Bit 0 RSEQ SETUP TX1ST 0 RPSIZ3 RPSIZ2 RPSIZ1 RPSIZ0 Write: Reset: Indeterminate after reset = Unimplemented Figure 13-7. USB Status Register (USR) MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Universal Serial Bus Module (USB) 175 Universal Serial Bus Module (USB) RSEQ — Received Data Sequence This bit indicates the type of data packet of the last received data packet on endpoint 0. RSEQ = 0 indicates the last received data packet is type DATA0. RSEQ = 1 indicates the last received data packet is type DATA1. 1 = Last token received on endpoint 0 is a DATA1 token 0 = Last token received on endpoint 0 is a DATA0 token SETUP — SETUP Token This bit is set when the received token packet for endpoint 0 is a SETUP token (PID = b1101). 1 = Last token received on endpoint 0 is a SETUP token 0 = Last token received on endpoint 0 is not a SETUP token TX1ST — Transmit First Flag This bit is set if the endpoint 0 transmit buffer empty flag (TBEF) is set when the control logic is setting the endpoint 0 receive buffer full flag (RBFF). This happens when TBEF is still set at the end of an endpoint 0 reception. 1 = IN transaction occurred before SETUP or OUT 0 = IN transaction occurred after SETUP or OUT RPSIZ[3:0] — Received Data Size The RPSIZ[3:0] indicates the number of received data bytes in a data packet. Reset will not affect these bits Data Sheet 176 MC68HC908BD48 — Rev. 2.0 Universal Serial Bus Module (USB) MOTOROLA Universal Serial Bus Module (USB) Registers 13.5.8 USB Endpoint 0 Data Registers 0 to 7 (UD0R0—UD0R7) Address: $0030–$0037 Bit 7 6 5 4 3 2 1 Bit 0 Read: UE0RDx7 UE0RDx6 UE0RDx5 UE0RDx4 UE0RDx3 UE0RDx2 UE0RDx1 UE0RDx0 Write: UE0TDx7 UE0TDx6 UE0TDx5 UE0TDx4 UE0TDx3 UE0TDx2 UE0TDx1 UE0TDx0 Reset: Indeterminate after reset Figure 13-8. USB Endpoint 0 Data Registers 0 to 7 (UD0R0–UD0R7) UE0RDx[7:0] — Endpoint 0 Receive Data Buffers These eight 8-bit buffers are serially loaded with OUT token or SETUP token data received over the USB’s D+ and D– lines. These buffers are for endpoint 0. UE0TDx[7:0] — Endpoint 0 Transmit Data Buffers These eight 8-bit buffers are loaded by user software with data to be sent on the USB bus on the next IN token directed at endpoint 0. 13.5.9 USB Endpoint 1/2 Data Registers 0 to 7 (UD1R0—UD1R7) Address: $0038–$003F Bit 7 6 5 4 3 2 1 Bit 0 Read: Write: UE1TDx7 UE1TDx6 UE1TDx5 UE1TDx4 Reset: UE1TDx UE1TDx2 UE1TDx1 UE1TDx0 Indeterminate after reset Figure 13-9. USB Endpoint 1 Data Registers 0 to 7 (UD1R0–UD1R7) UE1TDx[7:0] — Endpoint 1/2 Transmit Data Buffers These eight 8-bit buffers are loaded by user software with data to be sent on the USB bus on the next IN token directed at endpoint 1 or endpoint 2. The ENDADD bit in the USB control register 1 determines either endpoint 1 or endpoint 2 uses these buffers. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Universal Serial Bus Module (USB) 177 Universal Serial Bus Module (USB) Data Sheet 178 MC68HC908BD48 — Rev. 2.0 Universal Serial Bus Module (USB) MOTOROLA Data Sheet – MC68HC908BD48 Section 14. Multi-Master IIC Interface (MMIIC) 14.1 Contents 14.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179 14.3 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180 14.4 I/O Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180 14.5 Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .181 14.5.1 Multi-Master IIC Address Register (MMADR) . . . . . . . . . . 182 14.5.2 Multi-Master IIC Control Register (MMCR) . . . . . . . . . . . . 183 14.5.3 Multi-Master IIC Master Control Register (MIMCR) . . . . . . 184 14.5.4 Multi-Master IIC Status Register (MMSR) . . . . . . . . . . . . . 186 14.5.5 Multi-Master IIC Data Transmit Register (MMDTR) . . . . . . 188 14.5.6 Multi-Master IIC Data Receive Register (MMDRR) . . . . . . 189 14.6 Programming Considerations . . . . . . . . . . . . . . . . . . . . . . . . . 190 14.2 Introduction This Multi-master IIC (MMIIC) Interface is designed for internal serial communication between the MCU and other IIC devices. A hardware circuit generates "start" and "stop" signal, while byte by byte data transfer is interrupt driven by the software algorithm. Therefore, it can greatly help the software in dealing with other devices to have higher system efficiency in a typical digital monitor system. This module not only can be applied in internal communications, but can also be used as a typical command reception serial bus for factory setup and alignment purposes. It also provides the flexibility of hooking additional devices to an existing system for future expansion without adding extra hardware. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Multi-Master IIC Interface (MMIIC) 179 Multi-Master IIC Interface (MMIIC) This Multi-master IIC module uses the IICSCL clock line and the IICSDA data line to communicate with external DDC host or IIC interface. These two pins are shared with port pins PTD5 and PTD6 respectively. The outputs of IICSDA and IICSCL pins are open-drain type — no clamping diode is connected between the pin and internal VDD. The maximum data rate typically is 750k-bps. The maximum communication length and the number of devices that can be connected are limited by a maximum bus capacitance of 400pF. 14.3 Features • Compatibility with multi-master IIC bus standard • Software controllable acknowledge bit generation • Interrupt driven byte by byte data transfer • Calling address identification interrupt • Auto detection of R/W bit and switching of transmit or receive mode • Detection of START, repeated START, and STOP signals • Auto generation of START and STOP condition in master mode • Arbitration loss detection and No-ACK awareness in master mode • 8 selectable baud rate master clocks • Automatic recognition of the received acknowledge bit 14.4 I/O Pins The MMIIC module uses two I/O pins, shared with standard port I/O pins. The full name of the MMIIC I/O pins are listed in Table 14-1. The generic pin name appear in the text that follows. Table 14-1. Pin Name Conventions MMIIC Generic Pin Names: Full MCU Pin Names: Pin Selected for IIC Function By: SDA PTD6/IICSDA IICDATE bit in PDCR ($0049) SCL PTD5/IICSCL IICSCLE bit in PDCR ($0049) Data Sheet 180 MC68HC908BD48 — Rev. 2.0 Multi-Master IIC Interface (MMIIC) MOTOROLA Multi-Master IIC Interface (MMIIC) Registers Table 14-2. MMIIC I/O Register Summary Addr. Register Name $004E $004F Reset: 4 3 2 1 Bit 0 MMALIF MMNAKIF MMBB MMAST MMRW MMBR2 MMBR1 MMBR0 0 0 0 0 0 0 0 0 MMAD7 MMAD6 MMAD5 MMAD4 MMAD3 MMAD2 MMAD1 MMEXTAD 1 0 1 0 0 0 0 0 0 0 0 0 0 MMEN MMIEN 0 0 0 0 0 Read: Write: Reset: Read: Multi-Master IIC Control Register (MMCR) MMTXAK Write: Reset: Read: MMRXIF Multi-Master IIC Status Register (MMSR) $004D 5 Write: Multi-Master IIC Address Register (MMADR) $004C 6 Read: Multi-Master IIC $004A Master Control Register (MIMCR) $004B Bit 7 MMTXIF 0 0 0 MMATCH MMSRW MMRXAK 0 MMTXBE MMRXBF Write: 0 0 Reset: 0 0 0 0 1 0 1 0 MMTD7 MMTD6 MMTD5 MMTD4 MMTD3 MMTD2 MMTD1 MMTD0 1 1 1 1 1 1 1 1 MMRD6 MMRD5 MMRD4 MMRD3 MMRD2 MMRD1 MMRD0 0 0 0 0 0 0 0 Read: Multi-Master IIC Data Transmit Register (MMDTR) Write: Reset: Read: MMRD7 Multi-Master IIC Data Receive Register (MMDRR) Write: Reset: 0 = Unimplemented 14.5 Registers Six registers are associated with the Multi-master IIC module, they are outlined in the following sections. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Multi-Master IIC Interface (MMIIC) 181 Multi-Master IIC Interface (MMIIC) 14.5.1 Multi-Master IIC Address Register (MMADR) Address: $004B Bit 7 6 5 4 3 2 1 Bit 0 MMAD7 MMAD6 MMAD5 MMAD4 MMAD3 MMAD2 MMAD1 MMEXTAD 1 0 1 0 0 0 0 0 Read: Write: Reset: Figure 14-1. Multi-Master IIC Address Register (MMADR) MMAD[7:1] — Multi-Master Address These 7 bits can be the MMIIC interface’s own specific slave address in slave mode or the calling address when in master mode. Reset sets a default value of $A0. MMEXTAD — Multi-Master Expanded Address This bit is set to expand the calling address of the MMIIC in slave mode. When set, the MMIIC will acknowledge the general call address $00 and the matched 4-bit MSB address, MMAD[7:4]. For example, when MMAD[7:1] = $A1 and MMEXTAD = 1, the MMIIC calling address is $A0, and it will acknowledge calling addresses $00 and $A0 to $AF. Reset clears this bit. 1 = MMIIC calling address is $MMAD[7:4]0 MMIIC respond address is $00, and $MMAD[7:4]0 to $MMAD[7:4]F 0 = MMIIC address is $MMAD[7:1] Data Sheet 182 MC68HC908BD48 — Rev. 2.0 Multi-Master IIC Interface (MMIIC) MOTOROLA Multi-Master IIC Interface (MMIIC) Registers 14.5.2 Multi-Master IIC Control Register (MMCR) Address: $004C Bit 7 6 MMEN MMIEN 0 0 Read: 5 4 0 0 3 2 1 Bit 0 0 0 0 0 0 0 MMTXAK Write: Reset: 0 0 0 = Unimplemented Figure 14-2. Multi-Master IIC Control Register (MMCR) MMEN — Multi-Master IIC Enable This bit is set to enable the Multi-master IIC module. When MMEN = 0, module is disabled and all flags will restore to its poweron default states. Reset clears this bit. 1 = MMIIC module enabled 0 = MMIIC module disabled MMIEN — Multi-Master IIC Interrupt Enable When this bit is set, the MMTXIF, MMRXIF, MMALIF, and MMNAKIF flags are enabled to generate an interrupt request to the CPU. When MMIEN is cleared, the these flags are prevented from generating an interrupt request. Reset clears this bit. 1 = MMTXIF, MMRXIF, MMALIF, and/or MMNAKIF bit set will generate interrupt request to CPU 0 = MMTXIF, MMRXIF, MMALIF, and/or MMNAKIF bit set will not generate interrupt request to CPU MMTXAK — Transmit Acknowledge Enable This bit is set to disable the MMIIC from sending out an acknowledge signal to the bus at the 9th clock bit after receiving 8 data bits. When MMTXAK is cleared, an acknowledge signal will be sent at the 9th clock bit. Reset clears this bit. 1 = MMIIC does not send acknowledge signals at 9th clock bit 0 = MMIIC sends acknowledge signal at 9th clock bit MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Multi-Master IIC Interface (MMIIC) 183 Multi-Master IIC Interface (MMIIC) 14.5.3 Multi-Master IIC Master Control Register (MIMCR) Address: $004A Bit 7 6 5 4 3 2 1 Bit 0 MMALIF MMNAKIF MMBB MMAST MMRW MMBR2 MMBR1 MMBR0 0 0 0 0 0 0 0 0 Read: Write: Reset: Figure 14-3. Multi-Master IIC Master Control Register (MIMCR) MMALIF — Multi-Master Arbitration Lost Interrupt Flag This flag is set when software attempt to set MMAST but the MMBB has been set by detecting the start condition on the lines or when the MMIIC is transmitting a "1" to SDA line but detected a "0" from SDA line in master mode – an arbitration loss. This bit generates an interrupt request to the CPU if the MMIEN bit in MMCR is also set. This bit is cleared by writing "0" to it or by reset. 1 = Lost arbitration in master mode 0 = No arbitration lost MMNAKIF — No Acknowledge Interrupt Flag This flag is only set in master mode (MMAST = 1) when there is no acknowledge bit detected after one data byte or calling address is transferred. This flag also clears MMAST. MMNAKIF generates an interrupt request to CPU if the MMIEN bit in MMCR is also set. This bit is cleared by writing "0" to it or by reset. 1 = No acknowledge bit detected 0 = Acknowledge bit detected MMBB — Bus Busy Flag This flag is set after a start condition is detected (bus busy), and is cleared when a stop condition (bus idle) is detected or the MMIIC is disabled. Reset clears this bit. 1 = Start condition detected 0 = Stop condition detected or MMIIC is disabled Data Sheet 184 MC68HC908BD48 — Rev. 2.0 Multi-Master IIC Interface (MMIIC) MOTOROLA Multi-Master IIC Interface (MMIIC) Registers MMAST — Master Control Bit This bit is set to initiate a master mode transfer. In master mode, the module generates a start condition to the SDA and SCL lines, followed by sending the calling address stored in MMADR. When the MMAST bit is cleared by MMNAKIF set (no acknowledge) or by software, the module generates the stop condition to the lines after the current byte is transmitted. If an arbitration loss occurs (MMALIF = 1), the module reverts to slave mode by clearing MMAST, and releasing SDA and SCL lines immediately. This bit is cleared by writing "0" to it or by reset. 1 = Master mode operation 0 = Slave mode operation MMRW — Master Read/Write This bit will be transmitted out as bit 0 of the calling address when the module sets the MMAST bit to enter master mode. The MMRW bit determines the transfer direction of the data bytes that follows. When it is "1", the module is in master receive mode. When it is "0", the module is in master transmit mode. Reset clears this bit. 1 = Master mode receive 0 = Master mode transmit MMBR2–MMBR0 — Baud Rate Select These three bits select one of eight clock rates as the master clock when the module is in master mode. Since this master clock is derived the CPU bus clock, the user program should not execute the WAIT instruction when the MMIIC module in master mode. This will cause the SDA and SCL lines to hang, as the WAIT instruction places the MCU in WAIT mode, with CPU clock is halted. These bits are cleared upon reset. (See Table 14-3 . Baud Rate Select.) MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Multi-Master IIC Interface (MMIIC) 185 Multi-Master IIC Interface (MMIIC) Table 14-3. Baud Rate Select MMBR2 MMBR1 MMBR0 Baud Rate 0 0 0 750k 0 0 1 375k 0 1 0 187.5k 0 1 1 93.75k 1 0 0 46.875k 1 0 1 23.437k 1 1 0 11.719k 1 1 1 5.859k NOTE: CPU bus clock is external clock ÷ 4 = 6MHz 14.5.4 Multi-Master IIC Status Register (MMSR) Address: $004D Bit 7 Read: MMRXIF 6 MMTXIF Write: 0 0 Reset: 0 0 5 4 3 MMATCH MMSRW MMRXAK 0 0 1 2 0 0 1 Bit 0 MMTXBE MMRXBF 1 0 = Unimplemented Figure 14-4. Multi-Master IIC Status Register (MMSR) MMRXIF — Multi-Master IIC Receive Interrupt Flag This flag is set after the data receive register (MMDRR) is loaded with a new received data. Once the MMDRR is loaded with received data, no more received data can be loaded to the MMDRR register until the CPU reads the data from the MMDRR to clear MMRXBF flag. MMRXIF generates an interrupt request to CPU if the MMIEN bit in MMCR is also set. This bit is cleared by writing "0" to it or by reset; or when the MMEN = 0. 1 = New data in data receive register (MMDRR) 0 = No data received Data Sheet 186 MC68HC908BD48 — Rev. 2.0 Multi-Master IIC Interface (MMIIC) MOTOROLA Multi-Master IIC Interface (MMIIC) Registers MMTXIF — Multi-Master Transmit Interrupt Flag This flag is set when data in the data transmit register (MMDTR) is downloaded to the output circuit, and that new data can be written to the MMDTR. MMTXIF generates an interrupt request to CPU if the MMIEN bit in MMCR is also set. This bit is cleared by writing "0" to it or when the MMEN = 0. 1 = Data transfer completed 0 = Data transfer in progress MMATCH — Multi-Master Address Match This flag is set when the received data in the data receive register (MMDRR) is an calling address which matches with the address or its extended addresses (MMEXTAD=1) specified in the MMADR register. 1 = Received address matches MMADR 0 = Received address does not match MMSRW — Multi-Master Slave Read/Write This bit indicates the data direction when the module is in slave mode. It is updated after the calling address is received from a master device. MMSRW = 1 when the calling master is reading data from the module (slave transmit mode). MMSRW = 0 when the master is writing data to the module (receive mode). 1 = Slave mode transmit 0 = Slave mode receive MMRXAK — Multi-Master Receive Acknowledge When this bit is cleared, it indicates an acknowledge signal has been received after the completion of 8 data bits transmission on the bus. When MMRXAK is set, it indicates no acknowledge signal has been detected at the 9th clock; the module will release the SDA line for the master to generate "stop" or "repeated start" condition. Reset sets this bit. 1 = No acknowledge signal received at 9th clock bit 0 = Acknowledge signal received at 9th clock bit MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Multi-Master IIC Interface (MMIIC) 187 Multi-Master IIC Interface (MMIIC) MMTXBE — Multi-Master Transmit Buffer Empty This flag indicates the status of the data transmit register (MMDTR). When the CPU writes the data to the MMDTR, the MMTXBE flag will be cleared. MMTXBE is set when MMDTR is emptied by a transfer of its data to the output circuit. Reset sets this bit. 1 = Data transmit register empty 0 = Data transmit register full MMRXBF — Multi-Master Receive Buffer Full This flag indicates the status of the data receive register (MMDRR). When the CPU reads the data from the MMDRR, the MMRXBF flag will be cleared. MMRXBF is set when MMDRR is full by a transfer of data from the input circuit to the MMDRR. Reset clears this bit. 1 = Data receive register full 0 = Data receive register empty 14.5.5 Multi-Master IIC Data Transmit Register (MMDTR) Address: $004E Bit 7 6 5 4 3 2 1 Bit 0 MMTD7 MMTD6 MMTD5 MMTD4 MMTD3 MMTD2 MMTD1 MMTD0 1 1 1 1 1 1 1 1 Read: Write: Reset: Figure 14-5. Multi-Master IIC Data Transmit Register (MMDTR) When the MMIIC module is enabled, MMEN = 1, data written into this register depends on whether module is in master or slave mode. In slave mode, the data in MMDTR will be transferred to the output circuit when: • the module detects a matched calling address (MMATCH = 1), with the calling master requesting data (MMSRW = 1); or • the previous data in the output circuit has be transmitted and the receiving master returns an acknowledge bit, indicated by a received acknowledge bit (MMRXAK = 0). Data Sheet 188 MC68HC908BD48 — Rev. 2.0 Multi-Master IIC Interface (MMIIC) MOTOROLA Multi-Master IIC Interface (MMIIC) Registers If the calling master does not return an acknowledge bit (MMRXAK = 1), the module will release the SDA line for master to generate a "stop" or "repeated start" condition. The data in the MMDTR will not be transferred to the output circuit until the next calling from a master. The transmit buffer empty flag remains cleared (MMTXBE = 0). In master mode, the data in MMDTR will be transferred to the output circuit when: • the module receives an acknowledge bit (MMRXAK = 0), after setting master transmit mode (MMRW = 0), and the calling address has been transmitted; or • the previous data in the output circuit has be transmitted and the receiving slave returns an acknowledge bit, indicated by a received acknowledge bit (MMRXAK = 0). If the slave does not return an acknowledge bit (MMRXAK = 1), the master will generate a "stop" or "repeated start" condition. The data in the MMDTR will not be transferred to the output circuit. The transmit buffer empty flag remains cleared (MMTXBE = 0). The sequence of events for slave transmit and master transmit are illustrated in Figure 14-7. 14.5.6 Multi-Master IIC Data Receive Register (MMDRR) Address: $004F Bit 7 Read: MMRD7 6 5 4 3 2 1 Bit 0 MMRD6 MMRD5 MMRD4 MMRD3 MMRD2 MMRD1 MMRD0 0 0 0 0 0 0 0 Write: Reset: 0 = Unimplemented Figure 14-6. Multi-Master IIC Data Receive Register (MMDRR) When the MMIIC module is enabled, MMEN = 1, data in this read-only register depends on whether module is in master or slave mode. In slave mode, the data in MMDRR is: MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Multi-Master IIC Interface (MMIIC) 189 Multi-Master IIC Interface (MMIIC) • the calling address from the master when the address match flag is set (MMATCH = 1); or • the last data received when MMATCH = 0. In master mode, the data in the MMDRR is: • the last data received. When the MMDRR is read by the CPU, the receive buffer full flag is cleared (MMRXBF = 0), and the next received data is loaded to the MMDRR. Each time when new data is loaded to the MMDRR, the MMRXIF interrupt flag is set, indicating that new data is available in MMDRR. The sequence of events for slave receive and master receive are illustrated in Figure 14-7. 14.6 Programming Considerations When the MMIIC module detects an arbitration loss in master mode, it will release both SDA and SCL lines immediately. But if there are no further STOP conditions detected, the module will hang up. Therefore, it is recommended to have time-out software to recover from such ill condition. The software can start the time-out counter by looking at the MMBB (Bus Busy) flag in the MIMCR and reset the counter on the completion of one byte transmission. If a time-out occur, software can clear the MMEN bit (disable MMIIC module) to release the bus, and hence clearing the MMBB flag. This is the only way to clear the MMBB flag by software if the module hangs up due to a no STOP condition received. The MMIIC can resume operation again by setting the MMEN bit. Data Sheet 190 MC68HC908BD48 — Rev. 2.0 Multi-Master IIC Interface (MMIIC) MOTOROLA Multi-Master IIC Interface (MMIIC) Programming Considerations (a) Master Transmit Mode START Address MMTXBE=0 MMRW=0 MMAST=1 Data1 → MMDTR 0 ACK TX Data1 ACK MMTXBE=1 MMTXIF=1 Data3 → MMDTR MMTXBE=1 MMTXIF=1 Data2 → MMDTR TX DataN NAK STOP MMTXBE=1 MMNAKIF=1 MMTXIF=1 MMAST=0 DataN+2 → MMDTR MMTXBE=0 (b) Master Receive Mode START Address 1 ACK RX Data1 ACK Data1 → MMDRR MMRXIF=1 MMRXBF=1 MMRXBF=0 MMRW=1 MMAST=1 MMTXBE=0 (dummy data → MMDTR) RX DataN NAK STOP DataN → MMDRR MMNAKIF=1 MMRXIF=1 MMAST=0 MMRXBF=1 (c) Slave Transmit Mode START Address 1 ACK TX Data1 MMRXIF=1 MMRXBF=1 MMATCH=1 MMSRW=1 Data1 → MMDTR MMTXBE=1 MMRXBF=0 ACK MMTXBE=1 MMTXIF=1 Data2 → MMDTR TX DataN NAK STOP MMTXBE=1 MMNAKIF=1 MMTXIF=1 MMTXBE=0 DataN+2 → MMDTR (d) Slave Receive Mode START Address MMTXBE=0 MMRXBF=0 0 ACK MMRXIF=1 MMRXBF=1 MMATCH=1 MMSRW=0 RX Data1 ACK Data1 → MMDRR MMRXIF=1 MMRXBF=1 RX DataN NAK STOP DataN → MMDRR MMRXIF=1 MMRXBF=1 KEY: shaded data packets indicate a transmit by the MCU’s MMIIC module Figure 14-7. Data Transfer Sequences for Master/Slave Transmit/Receive Modes MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Multi-Master IIC Interface (MMIIC) 191 Multi-Master IIC Interface (MMIIC) Data Sheet 192 MC68HC908BD48 — Rev. 2.0 Multi-Master IIC Interface (MMIIC) MOTOROLA Data Sheet – MC68HC908BD48 Section 15. DDC12AB Interface 15.1 Contents 15.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193 15.3 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194 15.4 I/O Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194 15.5 DDC Protocols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196 15.6 Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .196 15.6.1 DDC Address Register (DADR) . . . . . . . . . . . . . . . . . . . . . 196 15.6.2 DDC2 Address Register (D2ADR) . . . . . . . . . . . . . . . . . . . 197 15.6.3 DDC Control Register (DCR) . . . . . . . . . . . . . . . . . . . . . . . 198 15.6.4 DDC Master Control Register (DMCR) . . . . . . . . . . . . . . . 199 15.6.5 DDC Status Register (DSR) . . . . . . . . . . . . . . . . . . . . . . . . 202 15.6.6 DDC Data Transmit Register (DDTR) . . . . . . . . . . . . . . . . 204 15.6.7 DDC Data Receive Register (DDRR) . . . . . . . . . . . . . . . . . 205 15.7 Programming Considerations . . . . . . . . . . . . . . . . . . . . . . . . . 206 15.2 Introduction This DDC12AB Interface module is used by the digital monitor to show its identification information to the video controller. It contains DDC1 hardware and a two-wire, bidirectional serial bus which is fully compatible with multi-master IIC bus protocol to support DDC2AB interface. This module not only can be applied in internal communications, but can also be used as a typical command reception serial bus for factory setup and alignment purposes. It also provides the flexibility of hooking additional devices to an existing system for future expansion without adding extra hardware. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet DDC12AB Interface 193 DDC12AB Interface This DDC12AB module uses the DDCSCL clock line and the DDCSDA data line to communicate with external DDC host or IIC interface. These two pins are shared with port pins PTD3 and PTD2 respectively. The outputs of DDCSDA and DDCSCL pins are open-drain type — no clamping diode is connected between the pin and internal VDD. The maximum data rate typically is 100k-bps. The maximum communication length and the number of devices that can be connected are limited by a maximum bus capacitance of 400pF. 15.3 Features • DDC1 hardware • Compatibility with multi-master IIC bus standard • Software controllable acknowledge bit generation • Interrupt driven byte by byte data transfer • Calling address identification interrupt • Auto detection of R/W bit and switching of transmit or receive mode • Detection of START, repeated START, and STOP signals • Auto generation of START and STOP condition in master mode • Arbitration loss detection and No-ACK awareness in master mode • 8 selectable baud rate master clocks • Automatic recognition of the received acknowledge bit 15.4 I/O Pins The DDC12AB module uses two I/O pins, shared with standard port I/O pins. The full name of the DDC12AB I/O pins are listed in Table 15-1. The generic pin name appear in the text that follows. Table 15-1. Pin Name Conventions DDC12AB Generic Pin Names: Full MCU Pin Names: Pin Selected for DDC Function By: SDA PTD2/DDCSDA DDCDATE bit in PDCR ($0049) SCL PTD3/DDCSCL DDCSCLE bit in PDCR ($0049) Data Sheet 194 MC68HC908BD48 — Rev. 2.0 DDC12AB Interface MOTOROLA DDC12AB Interface I/O Pins Table 15-2. DDC I/O Register Summary Addr. Register Name $0016 DDC Master Control Register (DMCR) Bit 7 6 5 4 3 2 1 Bit 0 ALIF NAKIF BB MAST MRW BR2 BR1 BR0 0 0 0 0 0 0 0 0 DAD7 DAD6 DAD5 DAD4 DAD3 DAD2 DAD1 EXTAD 1 0 1 0 0 0 0 0 0 0 DEN DIEN TXAK SCLIEN DDC1EN Reset: 0 0 0 0 0 0 0 0 Read: RXIF TXIF MATCH SRW RXAK SCLIF TXBE RXBF Write: 0 0 Reset: 0 0 0 0 1 0 1 0 DTD7 DTD6 DTD5 DTD4 DTD3 DTD2 DTD1 DTD0 Reset: 1 1 1 1 1 1 1 1 Read: DRD7 DRD6 DRD5 DRD4 DRD3 DRD2 DRD1 DRD0 0 0 0 0 0 0 0 0 D2AD7 D2AD6 D2AD5 D2AD4 D2AD3 D2AD2 D2AD1 0 0 0 0 0 0 0 Read: Write: Reset: Read: $0017 DDC Address Register (DADR) Write: Reset: DDC Control Register (DCR) $0018 DDC Status Register (DSR) $0019 $001A $001B DDC Data Transmit Register (DDTR) DDC Data Receive Register (DDRR) Read: 0 Write: 0 Read: Write: Write: Reset: Read: DDC2 Address Register $001C (D2ADR) 0 Write: Reset: 0 = Unimplemented MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet DDC12AB Interface 195 DDC12AB Interface 15.5 DDC Protocols In DDC1 protocol communication, the module is in transmit mode. The data written to the transmit register is continuously clocked out to the SDA line by the rising edge of the Vsync input signal. During DDC1 communication, a falling transition on the SCL line can be detected to generate an interrupt to the CPU for mode switching. In DDC2AB protocol communication, the module can be either in transmit mode or in receive mode, controlled by the calling master. In DDC2 protocol communication, the module will act as a standard IIC module, able to act as a master or a slave device. 15.6 Registers Seven registers are associated with the DDC module, they outlined in the following sections. 15.6.1 DDC Address Register (DADR) Address: $0017 Bit 7 6 5 4 3 2 1 Bit 0 DAD7 DAD6 DAD5 DAD4 DAD3 DAD2 DAD1 EXTAD 1 0 1 0 0 0 0 0 Read: Write: Reset: Figure 15-1. DDC Address Register (DADR) DAD[7:1] — DDC Address These 7 bits can be the DDC2 interface’s own specific slave address in slave mode or the calling address when in master mode. Reset sets a default value of $A0. Data Sheet 196 MC68HC908BD48 — Rev. 2.0 DDC12AB Interface MOTOROLA DDC12AB Interface Registers EXTAD — DDC Expanded Address This bit is set to expand the calling address of the DDC in slave mode. When set, the DDC will acknowledge the general call address $00 and the matched 4-bit MSB address, DAD[7:4]. For example, when DAD[7:1] = $A1 and EXTAD = 1, the DDC calling address is $A0, and it will acknowledge calling addresses $00 and $A0 to $AF. Reset clears this bit. 1 = DDC calling address is $DAD[7:4]0 DDC respond address is $00, and $DAD[7:4]0 to $DAD[7:4]F 0 = DDC address id $DAD[7:1] 15.6.2 DDC2 Address Register (D2ADR) Address: $001C Bit 7 6 5 4 3 2 1 D2AD7 D2AD6 D2AD5 D2AD4 D2AD3 D2AD2 D2AD1 0 0 0 0 0 0 0 Read: Bit 0 0 Write: Reset: 0 Figure 15-2. DDC2 Address Register (D2ADR) D2AD[7:1] — DDC2 Address These 7 bits represent the second slave address for the DDC2BI protocol. D2AD[7:1] should be set to the same value as DAD[7:1] in DADR if user application do not use DDC2BI. Reset clears all bits this register. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet DDC12AB Interface 197 DDC12AB Interface 15.6.3 DDC Control Register (DCR) Address: $0018 Bit 7 6 DEN DIEN 0 0 Read: 5 4 0 0 3 2 1 Bit 0 TXAK SCLIEN DDC1EN 0 0 0 0 Write: Reset: 0 0 0 = Unimplemented Figure 15-3. DDC Control Register (DCR) DEN — DDC Enable This bit is set to enable the DDC module. When DEN = 0, module is disabled and all flags will restore to its power-on default states. Reset clears this bit. 1 = DDC module enabled 0 = DDC module disabled DIEN — DDC Interrupt Enable When this bit is set, the TXIF, RXIF, ALIF, and NAKIF flags are enabled to generate an interrupt request to the CPU. When DIEN is cleared, the these flags are prevented from generating an interrupt request. Reset clears this bit. 1 = TXIF, RXIF, ALIF, and/or NAKIF bit set will generate interrupt request to CPU 0 = TXIF, RXIF, ALIF, and/or NAKIF bit set will not generate interrupt request to CPU TXAK — Transmit Acknowledge Enable This bit is set to disable the DDC from sending out an acknowledge signal to the bus at the 9th clock bit after receiving 8 data bits. When TXAK is cleared, an acknowledge signal will be sent at the 9th clock bit. Reset clears this bit. 1 = DDC does not send acknowledge signals at 9th clock bit 0 = DDC sends acknowledge signal at 9th clock bit Data Sheet 198 MC68HC908BD48 — Rev. 2.0 DDC12AB Interface MOTOROLA DDC12AB Interface Registers SCLIEN — SCL Interrupt Enable When this bit is set, the SCLIF flag is enabled to generate an interrupt request to the CPU. When SCLIEN is cleared, SCLIF is prevented from generating an interrupt request. Reset clears this bit. 1 = SCLIF bit set will generate interrupt request to CPU 0 = SCLIF bit set will not generate interrupt request to CPU DDC1EN — DDC1 Protocol Enable This bit is set to enable DDC1 protocol. The DDC1 protocol will use the Vsync input (from sync processor) as the master clock input to the DDC module. Vsync rising-edge will continuously clock out the data to the output circuit. No calling address comparison is performed. The SRW bit in DDC status register (DSR) will always read as "1". Reset clears this bit. 1 = DDC1 protocol enabled 0 = DDC1 protocol disabled 15.6.4 DDC Master Control Register (DMCR) Address: $0016 Bit 7 6 5 4 3 2 1 Bit 0 ALIF NAKIF BB MAST MRW BR2 BR1 BR0 0 0 0 0 0 0 0 0 Read: Write: Reset: Figure 15-4. DDC Master Control Register (DMCR) ALIF — DDC Arbitration Lost Interrupt Flag This flag is set when software attempt to set MAST but the BB has been set by detecting the start condition on the lines or when the DDC is transmitting a "1" to SDA line but detected a "0" from SDA line in master mode – an arbitration loss. This bit generates an interrupt request to the CPU if the DIEN bit in DCR is also set. This bit is cleared by writing "0" to it or by reset. 1 = Lost arbitration in master mode 0 = No arbitration lost MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet DDC12AB Interface 199 DDC12AB Interface NAKIF — No Acknowledge Interrupt Flag This flag is only set in master mode (MAST = 1) when there is no acknowledge bit detected after one data byte or calling address is transferred. This flag also clears MAST. NAKIF generates an interrupt request to CPU if the DIEN bit in DCR is also set. This bit is cleared by writing "0" to it or by reset. 1 = No acknowledge bit detected 0 = Acknowledge bit detected BB — Bus Busy Flag This flag is set after a start condition is detected (bus busy), and is cleared when a stop condition (bus idle) is detected or the DDC is disabled. Reset clears this bit. 1 = Start condition detected 0 = Stop condition detected or DDC is disabled MAST — Master Control Bit This bit is set to initiate a master mode transfer. In master mode, the module generates a start condition to the SDA and SCL lines, followed by sending the calling address stored in DADR. When the MAST bit is cleared by NAKIF set (no acknowledge) or by software, the module generates the stop condition to the lines after the current byte is transmitted. If an arbitration loss occurs (ALIF = 1), the module reverts to slave mode by clearing MAST, and releasing SDA and SCL lines immediately. This bit is cleared by writing "0" to it or by reset. 1 = Master mode operation 0 = Slave mode operation MRW — Master Read/Write This bit will be transmitted out as bit 0 of the calling address when the module sets the MAST bit to enter master mode. The MRW bit determines the transfer direction of the data bytes that follows. When it is "1", the module is in master receive mode. When it is "0", the module is in master transmit mode. Reset clears this bit. 1 = Master mode receive 0 = Master mode transmit Data Sheet 200 MC68HC908BD48 — Rev. 2.0 DDC12AB Interface MOTOROLA DDC12AB Interface Registers BR2–BR0 — Baud Rate Select These three bits select one of eight clock rates as the master clock when the module is in master mode. Since this master clock is derived the CPU bus clock, the user program should not execute the WAIT instruction when the DDC module in master mode. This will cause the SDA and SCL lines to hang, as the WAIT instruction places the MCU in WAIT mode, with CPU clock is halted. These bits are cleared upon reset. (See Table 15-3 . Baud Rate Select.) Table 15-3. Baud Rate Select BR2 BR1 BR0 Baud Rate 0 0 0 100k 0 0 1 50k 0 1 0 25k 0 1 1 12.5k 1 0 0 6.25k 1 0 1 3.125k 1 1 0 1.56k 1 1 1 0.78k NOTE: CPU bus clock is external clock ÷ 4 = 6MHz MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet DDC12AB Interface 201 DDC12AB Interface 15.6.5 DDC Status Register (DSR) Address: $0019 Bit 7 6 5 4 3 2 1 Bit 0 Read: RXIF TXIF MATCH SRW RXAK SCLIF TXBE RXBF Write: 0 0 Reset: 0 0 1 0 0 0 0 1 0 = Unimplemented Figure 15-5. DDC Status Register (DSR) RXIF — DDC Receive Interrupt Flag This flag is set after the data receive register (DDRR) is loaded with a new received data. Once the DDRR is loaded with received data, no more received data can be loaded to the DDRR register until the CPU reads the data from the DDRR to clear RXBF flag. RXIF generates an interrupt request to CPU if the DIEN bit in DCR is also set. This bit is cleared by writing "0" to it or by reset; or when the DEN = 0. 1 = New data in data receive register (DDRR) 0 = No data received TXIF — DDC Transmit Interrupt Flag This flag is set when data in the data transmit register (DDTR) is downloaded to the output circuit, and that new data can be written to the DDTR. TXIF generates an interrupt request to CPU if the DIEN bit in DCR is also set. This bit is cleared by writing "0" to it or when the DEN = 0. 1 = Data transfer completed 0 = Data transfer in progress MATCH — DDC Address Match This flag is set when the received data in the data receive register (DDRR) is an calling address which matches with the address or its extended addresses (EXTAD=1) specified in the DADR register. 1 = Received address matches DADR 0 = Received address does not match Data Sheet 202 MC68HC908BD48 — Rev. 2.0 DDC12AB Interface MOTOROLA DDC12AB Interface Registers SRW — DDC Slave Read/Write This bit indicates the data direction when the module is in slave mode. It is updated after the calling address is received from a master device. SRW = 1 when the calling master is reading data from the module (slave transmit mode). SRW = 0 when the master is writing data to the module (receive mode). 1 = Slave mode transmit 0 = Slave mode receive RXAK — DDC Receive Acknowledge When this bit is cleared, it indicates an acknowledge signal has been received after the completion of 8 data bits transmission on the bus. When RXAK is set, it indicates no acknowledge signal has been detected at the 9th clock; the module will release the SDA line for the master to generate "stop" or "repeated start" condition. Reset sets this bit. 1 = No acknowledge signal received at 9th clock bit 0 = Acknowledge signal received at 9th clock bit SCLIF — SCL Interrupt Flag This flag is set when a falling edge is detected on the SCL line, only if DDC1EN bit is set. SCLIF generates an interrupt request to CPU if the SCLIEN bit in DCR is also set. SCLIF is cleared by writing "0" to it or when the DCC1EN = 0, or DEN = 0. Reset clears this bit. 1 = Falling edge detected on SCL line 0 = No falling edge detected on SCL line TXBE — DDC Transmit Buffer Empty This flag indicates the status of the data transmit register (DDTR). When the CPU writes the data to the DDTR, the TXBE flag will be cleared. TXBE is set when DDTR is emptied by a transfer of its data to the output circuit. Reset sets this bit. 1 = Data transmit register empty 0 = Data transmit register full MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet DDC12AB Interface 203 DDC12AB Interface RXBF — DDC Receive Buffer Full This flag indicates the status of the data receive register (DDRR). When the CPU reads the data from the DDRR, the RXBF flag will be cleared. RXBF is set when DDRR is full by a transfer of data from the input circuit to the DDRR. Reset clears this bit. 1 = Data receive register full 0 = Data receive register empty 15.6.6 DDC Data Transmit Register (DDTR) Address: $001A Bit 7 6 5 4 3 2 1 Bit 0 DTD7 DTD6 DTD5 DTD4 DTD3 DTD2 DTD1 DTD0 1 1 1 1 1 1 1 1 Read: Write: Reset: Figure 15-6. DDC Data Transmit Register (DDTR) When the DDC module is enabled, DEN = 1, data written into this register depends on whether module is in master or slave mode. In slave mode, the data in DDTR will be transferred to the output circuit when: • the module detects a matched calling address (MATCH = 1), with the calling master requesting data (SRW = 1); or • the previous data in the output circuit has be transmitted and the receiving master returns an acknowledge bit, indicated by a received acknowledge bit (RXAK = 0). If the calling master does not return an acknowledge bit (RXAK = 1), the module will release the SDA line for master to generate a "stop" or "repeated start" condition. The data in the DDTR will not be transferred to the output circuit until the next calling from a master. The transmit buffer empty flag remains cleared (TXBE = 0). In master mode, the data in DDTR will be transferred to the output circuit when: Data Sheet 204 MC68HC908BD48 — Rev. 2.0 DDC12AB Interface MOTOROLA DDC12AB Interface Registers • the module receives an acknowledge bit (RXAK = 0), after setting master transmit mode (MRW = 0), and the calling address has been transmitted; or • the previous data in the output circuit has be transmitted and the receiving slave returns an acknowledge bit, indicated by a received acknowledge bit (RXAK = 0). If the slave does not return an acknowledge bit (RXAK = 1), the master will generate a "stop" or "repeated start" condition. The data in the DDTR will not be transferred to the output circuit. The transmit buffer empty flag remains cleared (TXBE = 0). The sequence of events for slave transmit and master transmit are illustrated in Figure 15-8. 15.6.7 DDC Data Receive Register (DDRR) Address: Read: $001B Bit 7 6 5 4 3 2 1 Bit 0 DRD7 DRD6 DRD5 DRD4 DRD3 DRD2 DRD1 DRD0 0 0 0 0 0 0 0 0 Write: Reset: = Unimplemented Figure 15-7. DDC Data Receive Register (DDRR) When the DDC module is enabled, DEN = 1, data in this read-only register depends on whether module is in master or slave mode. In slave mode, the data in DDRR is: • the calling address from the master when the address match flag is set (MATCH = 1); or • the last data received when MATCH = 0. In master mode, the data in the DDRR is: • the last data received. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet DDC12AB Interface 205 DDC12AB Interface When the DDRR is read by the CPU, the receive buffer full flag is cleared (RXBF = 0), and the next received data is loaded to the DDRR. Each time when new data is loaded to the DDRR, the RXIF interrupt flag is set, indicating that new data is available in DDRR. The sequence of events for slave receive and master receive are illustrated in Figure 15-8. 15.7 Programming Considerations When the DDC module detects an arbitration loss in master mode, it will release both SDA and SCL lines immediately. But if there are no further STOP conditions detected, the module will hang up. Therefore, it is recommended to have time-out software to recover from such ill condition. The software can start the time-out counter by looking at the BB (Bus Busy) flag in the DMCR and reset the counter on the completion of one byte transmission. If a time-out occur, software can clear the DEN bit (disable DDC module) to release the bus, and hence clearing the BB flag. This is the only way to clear the BB flag by software if the module hangs up due to a no STOP condition received. The DDC can resume operation again by setting the DEN bit. Data Sheet 206 MC68HC908BD48 — Rev. 2.0 DDC12AB Interface MOTOROLA DDC12AB Interface Programming Considerations (a) Master Transmit Mode START Address TXBE=0 MRW=0 MAST=1 Data1 → DDTR 0 TX Data1 ACK ACK TXBE=1 TXIF=1 Data3 → DDTR TXBE=1 TXIF=1 Data2 → DDTR TX DataN NAK STOP TXBE=1 NAKIF=1 TXIF=1 MAST=0 DataN+2 → DDTR TXBE=0 (b) Master Receive Mode START Address 1 RX Data1 ACK ACK Data1 → DDRR RXIF=1 RXBF=1 RXBF=0 MRW=1 MAST=1 TXBE=0 (dummy data → DDTR) RX DataN NAK STOP NAKIF=1 DataN → DDRR RXIF=1 MAST=0 RXBF=1 (c) Slave Transmit Mode START Address 1 TX Data1 ACK RXIF=1 RXBF=1 MATCH=1 SRW=1 Data1 → DDTR TXBE=1 RXBF=0 ACK TXBE=1 TXIF=1 Data2 → DDTR TX DataN NAK STOP TXBE=1 NAKIF=1 TXIF=1 TXBE=0 DataN+2 → DDTR (d) Slave Receive Mode START Address TXBE=0 RXBF=0 0 ACK RXIF=1 RXBF=1 MATCH=1 SRW=0 RX Data1 ACK Data1 → DDRR RXIF=1 RXBF=1 RX DataN NAK STOP DataN → DDRR RXIF=1 RXBF=1 KEY: shaded data packets indicate a transmit by the MCU’s DDC module Figure 15-8. Data Transfer Sequences for Master/Slave Transmit/Receive Modes MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet DDC12AB Interface 207 DDC12AB Interface Data Sheet 208 MC68HC908BD48 — Rev. 2.0 DDC12AB Interface MOTOROLA Data Sheet – MC68HC908BD48 Section 16. Sync Processor 16.1 Contents 16.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209 16.3 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211 16.4 I/O Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211 16.5 Functional Blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213 16.5.1 Polarity Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214 16.5.1.1 Hsync Polarity Detection . . . . . . . . . . . . . . . . . . . . . . . . 214 16.5.1.2 Vsync Polarity Detection . . . . . . . . . . . . . . . . . . . . . . . . 214 16.5.1.3 Composite Sync Polarity Detection . . . . . . . . . . . . . . . . 214 16.5.2 Sync Signal Counters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215 16.5.3 Polarity Controlled HSYNCO and VSYNCO Outputs. . . . . 215 16.5.4 Clamp Pulse Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216 16.5.5 Low Vertical Frequency Detect . . . . . . . . . . . . . . . . . . . . . 217 16.6 Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .217 16.6.1 Sync Processor Control & Status Register (SPCSR). . . . . 217 16.6.2 Sync Processor Input/Output Control Register (SPIOCR) . 219 16.6.3 Vertical Frequency Registers (VFRs). . . . . . . . . . . . . . . . . 221 16.6.4 Hsync Frequency Registers (HFRs). . . . . . . . . . . . . . . . . . 223 16.6.5 Sync Processor Control Register 1 (SPCR1). . . . . . . . . . . 225 16.6.6 H&V Sync Output Control Register (HVOCR) . . . . . . . . . . 226 16.7 System Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .227 16.2 Introduction The Sync Processor is designed to detect and process sync signals inside a digital monitor system — from separated Hsync and Vsync inputs, or from composite sync inputs such as Sync-On-Green (SOG). MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Sync Processor 209 Sync Processor After detection and the necessary polarity correction and/or sync separation, the corrected sync signals are sent out. The MCU can also send commands to other monitor circuitry, such as for the geometry correction and OSD, using the DDC12AB and/or the IIC communication channels. The block diagram of the Sync Processor is shown in Figure 16-1. NOTE: All quoted timings in this section assume an internal bus frequency of 6MHz. Data Sheet 210 MC68HC908BD48 — Rev. 2.0 Sync Processor MOTOROLA Sync Processor Features 16.3 Features Features of the Sync Processor include the following: • Polarity detector • Horizontal frequency counter • Vertical frequency counter • Low vertical frequency indicator (40.7Hz) • Polarity controlled HSYNCO and VSYNCO outputs: – From separate Hsync and Vsync – From composite sync on HSYNC or SOG input pin – From internal selectable free running Hsync and Vsync pulses • CLAMP pulse output to the external pre-amp chip • Internal schmitt trigger on HSYNC, VSYNC, and SOG input pins to improve noise immunity 16.4 I/O Pins The Sync Processor uses six I/O pins, with four pins shared with standard port I/O pins. The full name of the Sync Processor I/O pins are listed in Table 16-1. The generic pin name appear in the text that follows. Table 16-1. Pin Name Conventions Sync Processor Generic Pin Names: Full MCU Pin Names: Pin Selected for Sync Processor Function By: HSYNC HSYNC — VSYNC VSYNC — SOG PTE0/SOG/TCH0 SOGE bit in CONFIG1 ($001D) HSYNCO PTE1/HSYNCO HSYNCOE bit in CONFIG 1 ($001D) VSYNCO PTE2/VSYNCO VSYNCOE bit in CONFIG 1 ($001D) CLAMP PTD4/CLAMP CLAMPE bit in PDCR ($0049) MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Sync Processor 211 Sync Processor Table 16-2. Sync Processor I/O Register Summary Addr. Register Name $0040 Sync Processor Control and Status Register (SPCSR) $0041 Vertical Frequency High Register (VFHR) $0042 Vertical Frequency Low Register (VFLR) $0043 $0044 Hsync Frequency High Register (HFHR) Hsync Frequency Low Register (HFLR) $0045 Sync Processor I/O Control Register (SPIOCR) $0046 Sync Processor Control Register 1 (SPCR1) $0047 H&V Sync Output Control Register (HVOCR) Bit 7 6 VSIE VEDGE Read: 5 3 2 COMP VINVO HINVO VSIF Write: 1 Bit 0 VPOL HPOL 0 Reset: 0 0 0 0 0 0 0 0 Read: VOF 0 0 VF12 VF11 VF10 VF9 VF8 CPW1 CPW0 Write: Reset: 0 0 0 0 0 0 0 0 Read: VF7 VF6 VF5 VF4 VF3 VF2 VF1 VF0 Reset: 0 0 0 0 0 0 0 0 Read: HFH7 HFH6 HFH5 HFH4 HFH3 HFH2 HFH1 HFH0 Reset: 0 0 0 0 0 0 0 0 Read: HOVER 0 0 HFL4 HFL3 HFL2 HFL1 HFL0 0 0 0 0 0 0 0 0 COINV R BPOR SOUT 0 0 0 0 0 0 HPS1 HPS0 R R ATPOL FSHF 0 0 0 0 0 0 0 0 0 0 0 Write: Write: Write: Reset: Read: VSYNCS HSYNCS SOGSEL CLAMPOE Write: Reset: 0 Read: 0 LVSIF LVSIE Write: Reset: 0 0 Read: R HVOCR2 HVOCR1 HVOCR0 Write: Reset: 0 0 0 = Unimplemented Data Sheet 212 4 0 0 R 0 0 0 = Reserved MC68HC908BD48 — Rev. 2.0 Sync Processor MOTOROLA Sync Processor Functional Blocks 16.5 Functional Blocks EXTRACTED VSYNC SVF 1 A VSYNCO B S B S VSYNC VINVO A1 SOUT COMP VSIF POLARITY DETECT VPOL VSIE EDGE DETECT ONE SHOT VEDGE VFLR INTERNAL BUS CLOCK (6MHz) (125kHz) ÷ 48 VFHR VOF OVERFLOW DETECT 13-BIT COUNTER $C00 DETECT TO INTERRUPT LOGIC LVSIF LVSIE ONE SHOT HFLR CLK32/32.768 A1 HSYNC HFHR 13-BIT COUNTER HOVER OVERFLOW DETECT B S SOG SOGSEL POLARITY DETECT VPOL A1 B S HPOL COMP EXTRACTED VSYNC VSYNC EXTRACTOR BPOR SVF 2µs H/V SYNC PULSE GENERATOR HVOCR[2:0] B SHF COINV CLAMP PULSE GENERATOR CLAMP A1 S SOUT HINVO HSYNCO Figure 16-1. Sync Processor Block Diagram MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Sync Processor 213 Sync Processor 16.5.1 Polarity Detection 16.5.1.1 Hsync Polarity Detection The Hsync polarity detection circuit measures the length of high and low period of the HSYNC input. If the length of high is longer than L and the length of low is shorter than S, the HPOL bit will be "0", indicating a negative polarity HSYNC input. If the length of low is longer than L and the length of high is shorter than S, the HPOL bit will be "1", indicating a positive polarity HSYNC input. The table below shows three possible cases for HSYNC polarity detection — the conditions are selected by the HPS[1:0] bits in the Sync Processor Control Register 1 (SPCR1). Polarity Detection Pulse Width SPCR1 ($0046) Long is greater than (L) Short is less than (S) HPS1 HPS0 7µs 6µs 0 0 3.5µs 3µs 1 X 14µs 12µs 0 1 16.5.1.2 Vsync Polarity Detection The Vsync polarity detection circuit performs a similar function as for Hsync. If the length of high is longer than 4ms and the length of low is shorter than 2ms, the VPOL bit will be "0", indicating a negative polarity VSYNC input. If the length of low is longer than 4ms and the length of high is shorter than 2ms, the VPOL bit will be "1", indicating a positive polarity VSYNC input. 16.5.1.3 Composite Sync Polarity Detection When a composite sync signal is the input (COMP = 1 for composite sync processing), the HPOL bit = VPOL bit, and the polarity is detected using the VSYNC polarity detection criteria described in section 16.5.1.2. Data Sheet 214 MC68HC908BD48 — Rev. 2.0 Sync Processor MOTOROLA Sync Processor Functional Blocks 16.5.2 Sync Signal Counters There are two counters: a 13-bit horizontal frequency counter to count the number of horizontal sync pulses within a 32ms or 8ms period; and a 13-bit vertical frequency counter to count the number of system clock cycles between two vertical sync pulses. These two data can be read by the CPU to check the signal frequencies and to determine the video mode. The 13-bit vertical frequency register encompasses vertical frequency range from approximately 15Hz to 128kHz. Due to the asynchronous timing between the incoming VSYNC signal and internal system clock, there will be ±1 count error on reading the Vertical Frequency Registers (VFRs) for the same vertical frequency. The horizontal counter counts the pulses on HSYNC pin input, and is uploaded to the Hsync Frequency Registers (HFRs) every 32.768ms or 8.192ms. 16.5.3 Polarity Controlled HSYNCO and VSYNCO Outputs The processed sync signals are output on HSYNCO and VSYNCO when the corresponding bits in Configuration Register 0 ($001D) are set. The signal to these output pins depend on SOUT and COMP bits (see Table 16-3), with polarity controlled by ATPOL, HINVO, and VINVO bits as shown in Table 16-4. Table 16-3. Sync Output Control Sync Outputs: VSYNCO and HSYNCO SOUT COMP 1 X Free-running pulse with negative polarity 0 0 Sync outputs follow sync inputs VSYNC and HSYNC respectively, with polarity correction shown in Table 16-4. 0 1 HSYNCO follows the composite sync input and VSYNCO is the extracted Vsync (3 to 14µs delay to composite input), with polarity correction shown in Table 16-4. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Sync Processor 215 Sync Processor Table 16-4. Sync Output Polarity ATPOL SOUT VINVO or HINVO X 1 X Free-running pulse with negative polarity 0 0 0 Same polarity as sync input 0 0 1 Inverted polarity of sync input 1 0 0 Negative polarity sync output 1 0 1 Positive polarity sync output Sync Outputs: VSYNCO/HSYNCO When the SOUT bit is set, the HSYNCO output is a free-running pulse with 2µs width. Both HSYNCO and VSYNCO outputs are negative polarity, with frequencies selected by the H & V Sync Output Control Register (HVOCR). 16.5.4 Clamp Pulse Output When the CLAMPOE bit in SPIOCR is set to "1", a clamp signal is output on the CLAMP pin. This clamp pulse is triggered either on the leading edge or the trailing edge of HSYNC, controlled by BPOR bit, with the polarity controlled by the COINV bit. See Figure 16-2 . Clamp Pulse Output Timing. HSYNC (HPOL = 1) CLAMP (BPOR = 0) Pulse width = 0.33~2.1µs CLAMP (BPOR = 1) Pulse width = 0.33~2.1µs HSYNC (HPOL = 0) CLAMP (BPOR = 0) Pulse width = 0.33~2.1µs CLAMP (BPOR = 1) Pulse width = 0.33~2.1µs Figure 16-2. Clamp Pulse Output Timing Data Sheet 216 MC68HC908BD48 — Rev. 2.0 Sync Processor MOTOROLA Sync Processor Registers 16.5.5 Low Vertical Frequency Detect Logic monitors the value of the Vsync Frequency Register (VFR), and sets the low vertical frequency flag (LVSIF) when the value of VFR is higher than $C00 (frequency below 40.7Hz). LVSIF bit can generate an interrupt request to the CPU when the LVSIE bit is set and I-bit in the Condition Code Register is "0". The LVSIF bit can help the system to detect video off mode fast. 16.6 Registers Eight registers are associated with the Sync Processor, they outlined in the following sections. 16.6.1 Sync Processor Control & Status Register (SPCSR) Address: $0040 Bit 7 6 VSIE VEDGE Read: 4 3 2 COMP VINVO HINVO 0 0 0 VSIF Write: Reset: 5 1 Bit 0 VPOL HPOL 0 0 0 0 0 0 = Unimplemented Figure 16-3. Sync Processor Control & Status Register (SPCSR) VSIE — VSync Interrupt Enable When this bit is set, the VSIF flag is enabled to generate an interrupt request to the CPU. When VSIE is cleared, the VSIF flag is prevented from generating an interrupt request to the CPU. Reset clears this bit. 1 = VSIF bit set will generate interrupt request to CPU 0 = VSIF bit set does not generate interrupt request to CPU MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Sync Processor 217 Sync Processor VEDGE — VSync Interrupt Edge Select This bit specifies the triggering edge of Vsync interrupt. When it is "0", the rising edge of internal Vsync signal which is either from the VSYNC pin or extracted from the composite input signal will set VSIF flag. When it is "1", the falling edge of internal Vsync signal will set VSIF flag. Reset clears this bit. 1 = VSIF bit will be set by rising edge of Vsync 0 = VSIF bit will be set by falling edge of Vsync VSIF — VSync Interrupt Flag This flag is only set by the specified edge of the internal Vsync signal, which is either from the VSYNC input pin or extracted from the composite sync input signal. The triggering edge is specified by the VEDGE bit. VSIF generates an interrupt request to the CPU if the VSIE bit is also set. This bit is cleared by writing a "0" to it or by a reset. 1 = A valid edge is detected on the Vsync 0 = No valid Vsync is detected COMP — Composite Sync Input Enable This bit is set to enable the separator circuit which extracts the Vsync pulse from the composite sync input on HSYNC or SOG pin (select by SOGSEL bit). The extracted Vsync signal is used as it were from the VSYNC input. Reset clears this bit. 1 = Composite Sync Input Enabled 0 = Composite Sync Input Disabled VINVO —þVSYNCO Signal Polarity This bit, together with the ATPOL bit in SPCR1 controls the output polarity of the VSYNCO signal (see Table 16-5). HINVO — HSYNCO Signal Polarity This bit, together with the ATPOL bit in SPCR1 controls the output polarity of the HSYNCO signal (see Table 16-5). Data Sheet 218 MC68HC908BD48 — Rev. 2.0 Sync Processor MOTOROLA Sync Processor Registers Table 16-5. ATPOL, VINVO, and HINVO setting Sync Outputs: VSYNCO/HSYNCO ATPOL VINVO / HINVO 0 0 Same polarity as sync input 0 1 Inverted polarity of sync input 1 0 Negative polarity sync output 1 1 Positive polarity sync output VPOL — Vsync Input Polarity This bit indicates the polarity of the VSYNC input, or the extracted Vsync from a composite sync input (COMP=1). Reset clears this bit. 1 = Vsync is positive polarity 0 = Vsync is negative polarity HPOL —þHsync Input Polarity This bit indicates the polarity of the HSYNC input. This bit equals the VPOL bit when the COMP bit is set. Reset clears this bit. 1 = Hsync is positive polarity 0 = Hsync is negative polarity 16.6.2 Sync Processor Input/Output Control Register (SPIOCR) Address: $0045 Bit 7 6 5 4 COINV R 0 0 3 2 1 Bit 0 BPOR SOUT 0 0 Read: VSYNCS HSYNCS SOGSEL CLAMPOE Write: Reset: 0 0 = Unimplemented 0 R 0 = Reserved Figure 16-4. Sync Processor Input/Output Control Register (SPIOCR) VSYNCS — VSYNC Input State This read-only bit reflects the logical state of the VSYNC input. HSYNCS — HSYNC Input State This read-only bit reflects the logical state of the HSYNC input. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Sync Processor 219 Sync Processor COINV — Clamp Output Invert This bit is set to invert the clamp pulse output to negative. Reset clears this bit. 1 = clamp output is set for negative pulses 0 = clamp output is set for positive pulses SOGSEL —þ SOG Select This bit selects either the HSYNC pin or SOG pin as the composite sync signal input pin. Reset clears this bit. 1 = SOG pin is used as the composite sync input 0 = HSYNC pin is used as the composite sync input CLAMPOE —þClamp Output Enable This bit is set to enable the clamp pulse output circuitry. Reset clears this bit. 1 = Clamp pulse circuit enabled 0 = Clamp pulse circuit disabled BPOR — Back Porch This bit defines the triggering edge of the clamp pulse output relative to the HSYNC input. Reset clears this bit. 1 = Clamp pulse is generated on the trailing edge of HSYNC 0 = Clamp pulse is generated on the leading edge of HSYNC SOUT — Sync Output Enable This bit will select the output signals for the VSYNCO and HSYNCO pins. Reset clears this bit. 1 = VSYNCO and HSYNCO outputs are internally generated free-running sync pulses with frequencies determined by HVCOR[2:0] bits in HVCOR. 0 = VSYNCO and HSYNCO outputs are processed VSYNC and HSYNC inputs respectively Data Sheet 220 MC68HC908BD48 — Rev. 2.0 Sync Processor MOTOROLA Sync Processor Registers 16.6.3 Vertical Frequency Registers (VFRs) This register pair contains the 13-bit vertical frequency count value, an overflow bit, and the clamp pulse width selection bits. Address: Read: $0041 Bit 7 6 5 4 3 2 1 Bit 0 VOF 0 0 VF12 VF11 VF10 VF9 VF8 CPW1 CPW0 0 0 0 0 0 0 0 Write: Reset: 0 Figure 16-5. Vertical Frequency High Register Address: Read: $0042 Bit 7 6 5 4 3 2 1 Bit 0 VF7 VF6 VF5 VF4 VF3 VF2 VF1 VF0 0 0 0 0 0 0 0 0 Write: Reset: = Unimplemented Figure 16-6. Vertical Frequency Low Register VF[12:0] — Vertical Frame Frequency This read-only 13-bit contains information of the vertical frame frequency. An internal 13-bit counter counts the number of 8µs periods between two Vsync pulses. The most significant 5 bits of the counted value is transferred to the high byte register, and the least significant 8 bits is transferred to an intermediate buffer. When the high byte register is read, the 8-bit counted value stored in the intermediate buffer will be uploaded to the low byte register. Therefore, user program must read the high byte register first, then low byte register in order to get the complete counted value of one vertical frame. If the counter overflows, the overflow flag, VOF, will be set, indicating the counter value stored in the VFRs is meaningless. The data corresponds to the period of one vertical frame. This register can be read to determine if the frame frequency is valid, and to determine the video mode. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Sync Processor 221 Sync Processor The frame frequency is calculated by: 1 Vertical Frame Frequency = -------------------------------------------------VFR ± 1 × 48 × t CYC 1 = ------------------------------------VFR ± 1 × 8µ s for internal bus clock of 6 MHz Table 16-6 shows examples for the Vertical Frequency Register, all VFR numbers are in hexadecimal. Table 16-6. Sample Vertical Frame Frequencies VFR Max Freq. Min Freq. VFR Max Freq. Min Freq. $02A0 186.20 Hz 185.70 Hz $0780 65.10 Hz 65.00 Hz $03C0 130.34 Hz 130.07 Hz $0823 60.04 Hz 59.98 Hz $03C1 130.21 Hz 129.94 Hz $0824 60.01 Hz 59.95 Hz $03C2 130.07 Hz 129.80 Hz $0825 59.98 Hz 59.92 Hz $04E2 100.08 Hz 99.92 Hz $09C4 50.02 Hz 49.98 Hz $04E3 100.00 Hz 99.84 Hz $09C5 50.00 Hz 49.96 Hz $04E4 99.92 Hz 99.76 Hz $09C6 49.98 Hz 49.94 Hz $06F9 70.07 Hz 69.99 Hz $1FFD 15.266 Hz 15.262 Hz $06FA 70.03 Hz 69.95 Hz $1FFE 15.264 Hz 15.260 Hz $06FB 69.99 Hz 69.91 Hz $1FFF 15.262 Hz 15.258 Hz VOF — Vertical Frequency Counter Overflow This read-only bit is set when an overflow has occurred on the 13-bit vertical frequency counter. Reset clears this bit, and will be updated every vertical frame. An overflow occurs when the period of Vsync frame exceeds 64.768ms (a vertical frame frequency lower than 15.258Hz). 1 = A vertical frequency counter overflow has occurred 0 = No vertical frequency counter overflow has occurred Data Sheet 222 MC68HC908BD48 — Rev. 2.0 Sync Processor MOTOROLA Sync Processor Registers CPW[1:0] — Clamp Pulse Width The CPW1 and CPW0 bits are used to select the output clamp pulse width. Reset clears these bits, selecting a default clamp pulse width between 0.33µs and 0.375µs. These bits always read as Zeros. Table 16-7. Clamp Pulse Width CPW1 CPW0 Clamp Pulse Width 0 0 0.33µs to 0.375µs 0 1 0.5µs to 0.542µs 1 0 0.75µs to 0.792µs 1 1 2µs to 2.042µs 16.6.4 Hsync Frequency Registers (HFRs) This register pair contains the 13-bit Hsync frequency count value and an overflow bit. Address: Read: $0043 Bit 7 6 5 4 3 2 1 Bit 0 HFH7 HFH6 HFH5 HFH4 HFH3 HFH2 HFH1 HFH0 0 0 0 0 0 0 0 0 Write: Reset: Figure 16-7. Hsync Frequency High Register Address: Read: $0044 Bit 7 6 5 4 3 2 1 Bit 0 HOVER 0 0 HFL4 HFL3 HFL2 HFL1 HFL0 0 0 0 0 0 0 0 0 Write: Reset: = Unimplemented Figure 16-8. Hsync Frequency Low Register MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Sync Processor 223 Sync Processor HFH[7:0], HFL[4:0] — Horizontal Line Frequency This read-only 13-bit contains the number of horizontal lines in a 32ms window. An internal 13-bit counter counts the Hsync pulses within a 32ms window in every 32.768ms period. If the FSHF bit in SPCR1 is set, only the most 11-bits (HFH[7:0] & HFL[4:2]) will be updated by the counter. Thus, providing a Hsync pulse count in a 8ms window in every 8.192ms. The most significant 8 bits of counted value is transferred to the high byte register, and the least significant 5 bits is transferred to an intermediate buffer. When the high byte register is read, the 5-bit counted value stored in the intermediate buffer will be uploaded to the low byte register. Therefore, user the program must read the high byte register first then low byte register in order to get the complete counted value of Hsync pulses. If the counter overflows, the overflow flag, HOVER, will be set, indicating the number of Hsync pulses in 32ms are more than 8191 (213 –1), i.e. a Hsync frequency greater than 256kHz. For the 32ms window, the HFHR and HFLR are such that the frequency step unit in the 5-bit of HFLR is 0.03125kHz, and the step unit in the 8-bit HFHR is 1kHz. Therefore, the Hsync frequency can be easily calculated by: Hsync Frequency = [HFH + (HFL × 0.03125)]kHz where: HFH is the value of HFH[7:0] HFL is the value of HFL[4:0] HOVER — Hsync Frequency Counter Overflow This read-only bit is set when an overflow has occurred on the 13-bit Hsync frequency counter. Reset clears this bit, and will be updated every count period. An overflow occurs when the number Hsync pulses exceed 8191, a Hsync frequency greater than 256kHz. 1 = A Hsync frequency counter overflow has occurred 0 = No Hsync frequency counter overflow has occurred Data Sheet 224 MC68HC908BD48 — Rev. 2.0 Sync Processor MOTOROLA Sync Processor Registers 16.6.5 Sync Processor Control Register 1 (SPCR1) Address: $0046 Bit 7 Read: 6 4 3 2 1 Bit 0 HPS1 HPS0 R R ATPOL FSHF 0 0 0 0 0 0 LVSIF LVSIE Write: Reset: 5 0 0 0 = Unimplemented R = Reserved Figure 16-9. Sync Processor Control Register 1 (SPCR1) LVSIE — Low VSync Interrupt Enable When this bit is set, the LVSIF flag is enabled to generate an interrupt request to the CPU. When LVSIE is cleared, the LVSIF flag is prevented from generating an interrupt request to the CPU. Reset clears this bit. 1 = Low Vsync interrupt enabled 0 = Low Vsync interrupt disabled LVSIF — Low VSync Interrupt Flag This read-only bit is set when the value of VFR is higher than $C00 (vertical frame frequency below 40.7Hz). LVSIF generates an interrupt request to the CPU if the LVSIE is also set. This bit is cleared by writing a "0" to it or reset. 1 = Vertical frequency is below 40.7Hz 0 = Vertical frequency is higher than 40.7Hz HPS[1:0] — HSYNC input Detection Pulse Width These two bits control the detection pulse width of HSYNC input. Reset clears these two bits, setting a default middle frequency of HSYNC input. Table 16-8. HSYNC Polarity Detection Pulse Width HPS1 HPS0 Polarity Detection Pulse Width 0 0 Long > 7µs and Short < 6µs 1 X Long > 3.5µs and Short < 3µs 0 1 Long > 14µs and Short < 12µs MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Sync Processor 225 Sync Processor ATPOL — Auto Polarity This bit, together with the VINVO or HINVO bits in SPCSR controls the output polarity of the VSYNCO or HSYNCO signals respectively. Reset clears this bit (see Table 16-9). Table 16-9. ATPOL, VINVO, and HINVO setting Sync Outputs: VSYNCO/HSYNCO ATPOL VINVO / HINVO 0 0 Same polarity as sync input 0 1 Inverted polarity of sync input 1 0 Negative polarity sync output 1 1 Positive polarity sync output FSHF — Fast Horizontal Frequency Count This bit is set to shorten the measurement cycle of the horizontal frequency. If it is set, only HFH[7:0] and HFL[4:2] will be updated by the Hsync counter, providing a count in a 8ms window in every 8.192ms, with HFL[1:0] reading as zeros. Therefore, user can determine the horizontal frequency change within 8.192ms to protect critical circuitry. Reset clears this bit. 1 = Number of Hsync pulses is counted in an 8ms window 0 = Number of Hsync pulses is counted in a 32ms window 16.6.6 H&V Sync Output Control Register (HVOCR) Address: $0047 Bit 7 Read: 6 5 4 3 0 0 0 0 R 2 1 Bit 0 HVOCR2 HVOCR1 HVOCR0 Write: Reset: 0 0 0 = Unimplemented 0 0 R 0 0 0 = Reserved Figure 16-10. H&V Sync Output Control Register (HVOCR) Data Sheet 226 MC68HC908BD48 — Rev. 2.0 Sync Processor MOTOROLA Sync Processor System Operation HVOCR[2:0] — H&V Output Select Bits These three bits select the frequencies of the internal generated free-running sync pulses for output to HSYNCO and VSYNCO pins, when the SOUT bit is set in the SPIOCR. Reset clears these bits, setting a default horizontal frequency of 31.25kHz and a vertical frequency of 60Hz, a video mode of 640×480. Table 16-10. Free-Running HSYNC and VSYNC Options HSYNCO VSYNCO HVOCR Video Mode Pulse width Frequency Pulse width Frequency 000 Negative 2µs 31.25kHz Negative 192µs 59.98 Hz 640×480 001 Negative 2µs 43.48kHz Negative 138µs 84.92 Hz 640×480 010 Negative 2µs 48.78kHz Negative 123µs 60.00 Hz 1024×768 011 Negative 2µs 54.05kHz Negative 111µs 84.98 Hz 800×600 100 Negative 2µs 60.61kHz Negative 99µs 75.01 Hz 1024×768 101 Negative 2µs 80.00kHz Negative 75µs 74.98 Hz 1280×1024 110 Negative 2µs 90.91kHz Negative 66µs 84.96 Hz 1280×1024 111 Negative 2µs 105.26kHz Negative 57µs 85.02 Hz 1600×1200 16.7 System Operation This Sync Processor is designed to assist in determining the video mode of incoming HSYNC and VSYNC of various frequencies and polarities, and DPMS modes. In the DPMS standard, a no sync pulses definition can be detected when the value of the Hsync Frequency Register (the number of Hsync pulses) is less than one or when the VOF bit is set. Since the Hsync Frequency Register is updated repeatedly in every 32.768ms, and a valid Vsync must have a frequency greater than 40.7Hz, a valid Vsync pulse will arrive within the 32.768ms window. Therefore, the user should read the Hsync Frequency Register every 32.768ms to determine the presence of Hsync and/or Vsync pulses. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Sync Processor 227 Sync Processor Data Sheet 228 MC68HC908BD48 — Rev. 2.0 Sync Processor MOTOROLA Data Sheet – MC68HC908BD48 Section 17. Input/Output (I/O) Ports 17.1 Contents 17.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229 17.3 Port A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233 17.3.1 Port A Data Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233 17.3.2 Data Direction Register A . . . . . . . . . . . . . . . . . . . . . . . . . 234 17.3.3 Port A Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235 17.4 Port B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236 17.4.1 Port B Data Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236 17.4.2 Data Direction Register B . . . . . . . . . . . . . . . . . . . . . . . . . 237 17.4.3 Port B Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238 17.5 Port C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239 17.5.1 Port C Data Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239 17.5.2 Data Direction Register C . . . . . . . . . . . . . . . . . . . . . . . . . 240 17.5.3 Port C Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241 17.6 Port D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242 17.6.1 Port D Data Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242 17.6.2 Data Direction Register D. . . . . . . . . . . . . . . . . . . . . . . . . . 243 17.6.3 Port D Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245 17.7 Port E . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247 17.7.1 Port E Data Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247 17.7.2 Data Direction Register E. . . . . . . . . . . . . . . . . . . . . . . . . . 248 17.7.3 Port E Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250 17.2 Introduction Thirty-two (32) bidirectional input-output (I/O) pins form four parallel ports. All I/O pins are programmable as inputs or outputs. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Input/Output (I/O) Ports 229 Input/Output (I/O) Ports NOTE: Connect any unused I/O pins to an appropriate logic level, either VDD 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. Table 17-1. I/O Port Register Summary Addr. Register Name 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 Read: Port A Data Register Write: (PTA) Reset: $0000 Unaffected by reset Read: Port B Data Register Write: (PTB) Reset: $0001 Read: PTB7 PTB6 Read: 0 PTB3 0 PTC5 PTC4 PTC3 Unaffected by reset 0 PTD6 Port D Data Register Write: (PTD) Reset: $0003 PTB4 Unaffected by reset Port C Data Register Write: (PTC) Reset: $0002 PTB5 PTD5 PTD4 PTD3 Unaffected by reset Read: $0004 DDRA7 Data Direction Register A 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 DDRC5 DDRC4 DDRC3 DDRC2 DDRC1 DDRC0 0 0 0 0 0 0 Read: $0005 DDRB7 Data Direction Register B Write: (DDRB) Reset: 0 Read: $0006 Data Direction Register C Write: (DDRC) Reset: 0 0 0 0 = Unimplemented Data Sheet 230 MC68HC908BD48 — Rev. 2.0 Input/Output (I/O) Ports MOTOROLA Input/Output (I/O) Ports Introduction Table 17-1. I/O Port Register Summary (Continued) Addr. Register Name Bit 7 6 5 4 3 2 1 Bit 0 Read: Data Direction Register D Write: $0007 (DDRD) Reset: 0 DDRD6 DDRD5 DDRD4 DDRD3 DDRD2 DDRD1 DDRD0 0 0 0 0 0 0 0 0 Read: Port E Data Register Write: (PTE) Reset: 0 0 0 0 0 PTE2 PTE1 PTE0 Read: Data Direction Register E Write: $0009 (DDRE) Reset: 0 DDRE2 DDRE1 DDRE0 $0008 $001D $0028 $0049 $0059 Unaffected by reset 0 0 0 Read: Port D Configuration Write: Register (PDCR) Reset: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 PWM6E PWM5E PWM4E PWM3E PWM2E PWM1E PWM0E 0 0 0 0 0 0 0 IICDATE IICSCLE 0 0 Read: HSYNCOE VSYNCOE Configuration Register 0 Write: (CONFIG0) Reset: 0 0 Read: PWM7E PWM Control Register 1 Write: (PWMCR1) Reset: 0 0 SOGE 0 0 CLAMPE DDCSCLE DDCDATE USBD–E 0 0 0 Read: PWM15E PWM14E PWM13E PWM12E PWM11E PWM10E PWM Control Register 2 Write: (PWMCR2) Reset: 0 0 0 0 0 0 USBD+E 0 0 PWM9E PWM8E 0 0 = Unimplemented MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Input/Output (I/O) Ports 231 Input/Output (I/O) Ports Table 17-2. Port Control Register Bits Summary Port A B C D E Module Control Bit DDR 0 DDRA0 PWM8E PTA0/PWM8 1 DDRA1 PWM9E PTA1/PWM9 2 DDRA2 PWM10E PTA2/PWM10 3 DDRA3 PWM11E PTA3/PWM11 4 DDRA4 PWM12E PTA4/PWM12 5 DDRA5 PWM13E PTA5/PWM13 6 DDRA6 PWM14E PTA6/PWM14 7 DDRA7 PWM15E PTA7/PWM15 0 DDRB0 PWM0E PTB0/PWM0 1 DDRB1 PWM1E PTB1/PWM1 2 DDRB2 PWM2E PTB2/PWM2 3 DDRB3 PWM3E PTB3/PWM3 4 DDRB4 PWM4E PTB4/PWM4 5 DDRB5 PWM5E PTB5/PWM5 6 DDRB6 PWM6E PTB6/PWM6 7 DDRB7 PWM7E PTB7/PWM7 0 DDRC0 PTC0/ADC0 1 DDRC1 PTC1/ADC1 2 DDRC2 3 DDRC3 4 DDRC4 PTC4/ADC4 5 DDRC5 PTC5/ADC5 0 DDRD0 1 DDRD1 2 DDRD2 3 DDRD3 4 DDRD4 5 DDRD5 6 DDRD6 0 DDRE0 1 DDRE1 2 DDRE2 Module PWM PWM ADC Register PWMCR2 $0059 PWMCR1 $0028 ADSCR $005D USB DDC12AB PDCR $0049 SYNC MMIIC SYNC/TIM SYNC CONFIG0 $001D Data Sheet 232 Control Bit ADCH[4:0] Pin PTC2/ADC2 PTC3/ADC3/ D+E PTD0/D+ D–E PTD1/D– DDCDATE PTD2/DDCSDA DDCSCLE PTD3/DDCSCL CLAMPE PTD4/CLAMP IICSCLE PTD5/IICSCL IICDATE PTD6/IICSDA SOGE PTE0/SOG/TCH0 HSYNCOE PTE1/HSYNCO VSYNCOE PTE2/VSYNCO MC68HC908BD48 — Rev. 2.0 Input/Output (I/O) Ports MOTOROLA Input/Output (I/O) Ports Port A 17.3 Port A Port A is an 8-bit special-function port that shares all eight of its pins with the pulse width modulator (PWM). 17.3.1 Port A Data Register The port A data register (PTA) 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 PWM10 PWM9 PWM8 Read: Write: Reset: Alternate Function: Unaffected by reset PWM15 PWM14 PWM13 PWM12 PWM11 Figure 17-1. Port A Data Register (PTA) PTA7–PTA0 — 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. PWM15–PWM8 — PWM Outputs 15–8 The PWM output enable bits PWM15E–PWM8E, in PWM control register 2 (PWMCR2) enable port A pins as PWM output pins. (See 17.3.3 Port A Options.) MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Input/Output (I/O) Ports 233 Input/Output (I/O) Ports 17.3.2 Data Direction Register A Data direction register A (DDRA) 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: Figure 17-2. Data Direction Register A (DDRA) DDRA7–DDRA0 — Data Direction Register A Bits These read/write bits control port A data direction. Reset clears DDRA7–DDRA0, 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 17-3 shows the port A I/O logic. INTERNAL DATA BUS READ DDRA ($0004) WRITE DDRA ($0004) RESET DDRAx WRITE PTA ($0000) PTAx PTAx READ PTA ($0000) Figure 17-3. Port A I/O Circuit Data Sheet 234 MC68HC908BD48 — Rev. 2.0 Input/Output (I/O) Ports MOTOROLA Input/Output (I/O) Ports Port A 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 17-3 summarizes the operation of the port A pins. Table 17-3. Port A Pin Functions PTAPUE Bit DDRA Bit PTA Bit Accesses to DDRA I/O Pin Mode Accesses to PTA Read/Write Read Write 0 0 X(1) Input, Hi-Z(2) DDRA7–DDRA0 Pin PTA7–PTA0(3) X 1 X Output DDRA7–DDRA0 PTA7–PTA0 PTA7–PTA0 NOTES: 1. X = Don’t care 2. Hi-Z = High impedance 3. Writing affects data register, but does not affect input. 17.3.3 Port A Options The PWM control register 2 (PWMCR2) selects the port A pins for PWM function or as standard I/O function. See 11.4.2 PWM Control Registers 1 and 2 (PWMCR1:PWMCR2). Address: $0059 Bit 7 6 5 4 3 2 1 Bit 0 PWM9E PWM8E 0 0 Read: PWM15E PWM14E PWM13E PWM12E PWM11E PWM10E Write: Reset: 0 0 0 0 0 0 Figure 17-4. PWM Control Register 1 (PWMCR1) PWM15E–PWM8E — PWM Output Enable 15–8 Setting a bit to "1" will configure the corresponding PTAx/PWMx pin for PWM output function. Reset clears these bits. 1 = PTAx/PWMx pin configured as PWMx output pin 0 = PTAx/PWMx pin configured as standard I/O pin MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Input/Output (I/O) Ports 235 Input/Output (I/O) Ports 17.4 Port B Port B is an 8-bit special-function port that shares all eight of its pins with the pulse width modulator (PWM). 17.4.1 Port B Data Register The port B data register (PTB) contains a data latch for each of the eight port pins. Address: $0001 Bit 7 6 5 4 3 2 1 Bit 0 PTB7 PTB6 PTB5 PTB4 PTB3 PTB2 PTB1 PTB0 PWM2 PWM1 PWM0 Read: Write: Reset: Alternate Function: Unaffected by reset PWM7 PWM6 PWM5 PWM4 PWM3 Figure 17-5. Port B Data Register (PTB) PTB7–PTB0 — 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. PWM7–PWM0 — PWM Outputs 7–0 The PWM output enable bits PWM7E–PWM0E, in PWM control register 1 (PWMCR1) enable port B pins as PWM output pins. (See 17.4.3 Port B Options.) Data Sheet 236 MC68HC908BD48 — Rev. 2.0 Input/Output (I/O) Ports MOTOROLA Input/Output (I/O) Ports Port B 17.4.2 Data Direction Register B Data direction register B (DDRB) 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 17-6. Data Direction Register B (DDRB) DDRB7–DDRB0 — Data Direction Register B Bits These read/write bits control port B data direction. Reset clears DDRB7–DDRB0, 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. Figure 17-7 shows the port B I/O logic. INTERNAL DATA BUS READ DDRB ($0005) WRITE DDRB ($0005) RESET DDRBx WRITE PTB ($0001) PTBx PTBx READ PTB ($0001) Figure 17-7. Port B I/O Circuit MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Input/Output (I/O) Ports 237 Input/Output (I/O) Ports 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 17-4 summarizes the operation of the port B pins. Table 17-4. Port B Pin Functions DDRB Bit PTB Bit Accesses to DDRB I/O Pin Mode Accesses to PTB Read/Write Read Write 0 X(1) Input, Hi-Z(2) DDRB7–DDRB0 Pin PTB7–PTB0(3) 1 X Output DDRB7–DDRB0 PTB7–PTB0 PTB7–PTB0 Notes: 1. X = Don’t care 2. Hi-Z = High impedance 3. Writing affects data register, but does not affect input. 17.4.3 Port B Options The PWM control register 1 (PWMCR1) selects the port B pins for PWM function or as standard I/O function. See 11.4.2 PWM Control Registers 1 and 2 (PWMCR1:PWMCR2). Address: $0028 Bit 7 6 5 4 3 2 1 Bit 0 PWM7E PWM6E PWM5E PWM4E PWM3E PWM2E PWM1E PWM0E 0 0 0 0 0 0 0 0 Read: Write: Reset: Figure 17-8. PWM Control Register 1 (PWMCR1) PWM7E–PWM0E — PWM Output Enable 7–0 Setting a bit to "1" will configure the corresponding PTBx/PWMx pin for PWM output function. Reset clears these bits. 1 = PTBx/PWMx pin configured as PWMx output pin 0 = PTBx/PWMx pin configured as standard I/O pin Data Sheet 238 MC68HC908BD48 — Rev. 2.0 Input/Output (I/O) Ports MOTOROLA Input/Output (I/O) Ports Port C 17.5 Port C Port C is an 6-bit special-function port that shares all six of its pins with the analog-to-digital converter (ADC) module. 17.5.1 Port C Data Register The port C data register (PTC) contains a data latch for each of the seven port C pins. Address: Read: $0002 Bit 7 6 0 0 5 4 3 2 1 Bit 0 PTC5 PTC4 PTC3 PTC2 PTC1 PTC0 ADC2 ADC1 ADC0 Write: Reset: Alternate Function: Unaffected by reset ADC5 ADC4 ADC3 = Unimplemented Figure 17-9. Port C Data Register (PTC) PTC5–PTC0 — 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. ADC5–ADC0 — Analog-to-Digital Input Bits ADC5–ADC0 are pins used for the input channels to the analog-todigital converter module. The channel select bits in the ADC Status and Control Register define which port C pin will be used as an ADC input and overrides any control from the port I/O logic by forcing that pin as the input to the analog circuitry. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Input/Output (I/O) Ports 239 Input/Output (I/O) Ports NOTE: Care must be taken when reading port C while applying analog voltages to ADC5–ADC0 pins. If the appropriate ADC channel is not enabled, excessive current drain may occur if analog voltages are applied to the PTCx/ADCx pin, while PTC is read as a digital input. Those ports not selected as analog input channels are considered digital I/O ports. 17.5.2 Data Direction Register C Data direction register C (DDRC) 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: Read: $0006 Bit 7 6 0 0 5 4 3 2 1 Bit 0 DDRC5 DDRC4 DDRC3 DDRC2 DDRC1 DDRC0 0 0 0 0 0 0 Write: Reset: 0 0 = Unimplemented Figure 17-10. Data Direction Register C (DDRC) DDRC5–DDRC0 — Data Direction Register C Bits These read/write bits control port C data direction. Reset clears DDRC5–DDRC0, 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. Figure 17-11 shows the port C I/O logic. Data Sheet 240 MC68HC908BD48 — Rev. 2.0 Input/Output (I/O) Ports MOTOROLA Input/Output (I/O) Ports Port C READ DDRC ($0006) INTERNAL DATA BUS WRITE DDRC ($0006) RESET DDRCx WRITE PTC ($0002) PTCx PTCx READ PTC ($0002) Figure 17-11. 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 17-5 summarizes the operation of the port C pins. Table 17-5. Port C Pin Functions Accesses to DDRC PTCPUE Bit DDRC Bit PTC Bit Accesses to PTC I/O Pin Mode Read/Write Read Write 0 0 X Input, Hi-Z(2) DDRC5–DDRC0 Pin PTC5–PTC0(3) X 1 X Output DDRC5–DDRC0 PTC5–PTC0 PTC5–PTC0 Notes: 1. X = Don’t care 2. Hi-Z = High impedance 3. Writing affects data register, but does not affect input. 17.5.3 Port C Options The ADCH4–ADCH0 bits in the ADC Status and Control Register (ADSCR) defines which PTCx/ADCx pin is used as an ADC input and overrides any control from the port I/O logic by forcing that pin as the input to the analog circuitry. See 12.8.1 ADC Status and Control Register. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Input/Output (I/O) Ports 241 Input/Output (I/O) Ports 17.6 Port D Port D is an 7-bit special-function port that shares two of its pins with the multi-master IIC (MMIIC) module, one of its pins with the sync processor, two of its pins with the DDC12AB module, and two of its pins with the USB module. NOTE: PTD1–PTD0 are 3.3V pins. 17.6.1 Port D Data Register The port D data register (PTD) contains a data latch for each of the eight port D pins. Address: $0003 Bit 7 Read: 6 5 4 3 2 1 Bit 0 PTD6 PTD5 PTD4 PTD3 PTD2 PTD1 PTD0 D– D+ 0 Write: Reset: Alternate Function: Unaffected by reset IICSDA IICSCL CLAMP DDCSCL DDCSDA = Unimplemented Figure 17-12. Port D Data Register (PTD) PTD6–PTD0 — Port D Data Bits These read/write bits are software-programmable. Data direction of each port D pin is under the control of the corresponding bit in data direction register D. Reset has no effect on port D data. IICSDA, IICSCL — Multi-master IIC Data and Clock pins The PTD6/IICSDA and PTD5/IICSCL pins are multi-master IIC data and clock pins. When the IICDATE and IICSCLE bits in the port D configuration register (PDCR) is clear, the PTD6/IICSDA and PTD5/IICSCL pins are available for general-purpose I/O. See 17.6.3 Port D Options. Data Sheet 242 MC68HC908BD48 — Rev. 2.0 Input/Output (I/O) Ports MOTOROLA Input/Output (I/O) Ports Port D CLAMP — Sync Processor Clamp pulse output pin The PTD4/CLAMP pin is the sync processor clamp pulse output pin. When the CLAMPE bit in the port D configuration register (PDCR) is clear, the PTD4/CLAMP pin is available for general-purpose I/O. See 17.6.3 Port D Options. DDCSCL, DDCSDA — DDC12AB Data and Clock pins The PTD3/DDCSCL and PTD2/DDCSDA pins are DDC12AB clock and data pins respectively. When the DDCSCLE and DDCDATE bits in the port D configuration register (PDCR) is clear, the PTD3/DDCSCL and PTD2/DDCSDA pins are available for generalpurpose I/O. See 17.6.3 Port D Options. D–, D+ — USB I/O pins The PTD1/D– and PTD0/D+ pins are the USB port pins. When the USBD–E and USBD+E bits in the port D configuration register (PDCR) is clear, the PTD1/D– and PTD0/D+ pins are available for generalpurpose I/O. See 17.6.3 Port D Options. 17.6.2 Data Direction Register D Data direction register D (DDRD) 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 Read: 6 5 4 3 2 1 Bit 0 DDRD6 DDRD5 DDRD4 DDRD3 DDRD2 DDRD1 DDRD0 0 0 0 0 0 0 0 0 Write: Reset: 0 Figure 17-13. Data Direction Register D (DDRD) DDRD6–DDRD0 — Data Direction Register D Bits These read/write bits control port D data direction. Reset clears DDRD6–DDRD0, configuring all port D pins as inputs. 1 = Corresponding port D pin configured as output 0 = Corresponding port D pin configured as input MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Input/Output (I/O) Ports 243 Input/Output (I/O) Ports 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. Figure 17-14 shows the port D I/O logic. READ DDRD ($0007) INTERNAL DATA BUS WRITE DDRD ($0007) RESET DDRDx WRITE PTD ($0003) PTDx PTDx READ PTD ($0003) Figure 17-14. 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 17-6 summarizes the operation of the port D pins. Table 17-6. Port D Pin Functions Accesses to DDRD PTDPUE Bit DDRD Bit PTD Bit Accesses to PTD I/O Pin Mode Read/Write Read Write 0 0 X Input, Hi-Z(2) DDRD6–DDRD0 Pin PTD6–PTD0(3) X 1 X Output DDRD6–DDRD0 PTD6–PTD0 PTD6–PTD0 Notes: 1. X = Don’t care 2. Hi-Z = High impedance 3. Writing affects data register, but does not affect input. Data Sheet 244 MC68HC908BD48 — Rev. 2.0 Input/Output (I/O) Ports MOTOROLA Input/Output (I/O) Ports Port D 17.6.3 Port D Options The port D configuration register (PDCR) selects the port D pins for module function or as standard I/O function. Address: $0049 Bit 7 Read: 6 5 IICDATE IICSCLE 0 0 4 3 2 1 Bit 0 0 CLAMPE DDCSCLE DDCDATE USBD–E USBD+E Write: Reset: 0 0 0 0 0 0 = Unimplemented Figure 17-15. Port D Configuration Register (PDCR) IICDATE — MMIIC Data Pin Enable This bit is set to configure the PTD6/IICSDA pin for IICSDA function. Reset clears this bit. 1 = PTD6/IICSDA pin configured as IICSDA pin 0 = PTD6/IICSDA pin configured as standard I/O pin IICSCLE — MMIIC Clock Pin Enable This bit is set to configure the PTD5/IICSCL pin for IICSCL function. Reset clears this bit. 1 = PTD5/IICSCL pin configured as IICSCL pin 0 = PTD5/IICSCL pin configured as standard I/O pin CLAMP — CLAMP Pin Enable This bit is set to configure the PTD4/CLAMP pin for sync processor clamp pulse output. Reset clears this bit. 1 = PTD4/CLAMP pin configured as CLAMP pin 0 = PTD4/CLAMP pin configured as standard I/O pin DDCSCLE — DDC Clock Pin Enable This bit is set to configure the PTD3/DDCSCL pin for DDCSCL function. Reset clears this bit. 1 = PTD3/DDCSCL pin configured as DDCSCL pin 0 = PTD3/DDCSCL pin configured as standard I/O port MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Input/Output (I/O) Ports 245 Input/Output (I/O) Ports DDCDATE — DDC Data Pin Enable This bit is set to configure the PTD2/DDCSDA pin for DDCSDA function. Reset clears this bit. 1 = PTD2/DDCSDA pin configured as DDCSDA pin 0 = PTD2/DDCSDA pin configured as standard I/O port USBD–E — USB D– Pin Enable This bit is set to configure the PTD1/D– pin for D– function. Reset clears this bit. 1 = PTD1/D– pin configured as D– pin 0 = PTD1/D– pin configured as standard I/O port USBD+E — USB D+ Pin Enable This bit is set to configure the PTD0/D+ pin for D+ function. Reset clears this bit. 1 = PTD0/D+ pin configured as D+ pin 0 = PTD0/D+ pin configured as standard I/O port Data Sheet 246 MC68HC908BD48 — Rev. 2.0 Input/Output (I/O) Ports MOTOROLA Input/Output (I/O) Ports Port E 17.7 Port E Port E is a 3-bit special-function port that shares all of its pins with the sync processor. 17.7.1 Port E Data Register The port E data register contains a data latch for each of the three port E pins. Address: Read: $0008 Bit 7 6 5 4 3 0 0 0 0 0 2 1 Bit 0 PTE2 PTE1 PTE0 Write: Reset: Unaffected by reset Alternate Function: VSYNCO HSYNCO SOG or TCH0 = Unimplemented Figure 17-16. Port E Data Register (PTE) PTE2–PTE0 — Port E Data Bits PTE2–PTE0 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. VSYNCO — Vsync Output The PTE2/VSYNCO pin is the Vsync output from the sync processor. When the VSYNCOE is clear, the PTE2/VSYNCO pin is available for general-purpose I/O. See 17.7.3 Port E Options. HSYNC — Hsync Output The PTE1/HSYNCO pin is the Hsync output from the sync processor. When the HSYNCOE is clear, the PTE1/HSYNCO pin is available for general-purpose I/O. See 17.7.3 Port E Options. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Input/Output (I/O) Ports 247 Input/Output (I/O) Ports SOG/TCH0 — SOG Output or TCH0 Input The PTE0/SOG/TCH0 pin is the SOG input for the sync processor or the input capture of the TIM channel 0. See 17.7.3 Port E Options. 17.7.2 Data Direction Register E Data direction register E (DDRE) 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: $000C Bit 7 6 5 4 3 0 0 0 0 0 2 1 Bit 0 DDRE2 DDRE1 DDRE0 0 0 0 Write: Reset: 0 0 0 0 0 = Unimplemented Figure 17-17. Data Direction Register E (DDRE) DDRE2–DDRE0 — Data Direction Register E Bits These read/write bits control port E data direction. Reset clears DDRE2–DDRE0, configuring all port E pins as inputs. 1 = Corresponding port E pin configured as output 0 = Corresponding port E pin configured as input 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. Figure 17-18 shows the port E I/O logic. Data Sheet 248 MC68HC908BD48 — Rev. 2.0 Input/Output (I/O) Ports MOTOROLA Input/Output (I/O) Ports Port E INTERNAL DATA BUS READ DDRE ($0009) WRITE DDRE ($0009) RESET DDREx WRITE PTE ($0008) PTEx PTEx READ PTE ($0008) Figure 17-18. 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 17-7 summarizes the operation of the port E pins. Table 17-7. Port E Pin Functions Accesses to DDRE DDRE Bit PTE Bit Accesses to PTE I/O Pin Mode Read/Write Read Write 0 X(1) Input, Hi-Z(2) DDRE2–DDRE0 Pin PTE2–PTE0(3) 1 X Output DDRE2–DDRE0] PTE2–PTE0 PTE2–PTE0 Notes: 1. X = Don’t care 2. Hi-Z = High impedance 3. Writing affects data register, but does not affect input. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Input/Output (I/O) Ports 249 Input/Output (I/O) Ports 17.7.3 Port E Options The configuration register 0 (CONFIG0) selects the port E pins for module function or as standard I/O function. Address: $001D Bit 7 6 5 Read: HSYNCOE VSYNCOE 4 3 2 1 Bit 0 0 0 0 0 0 0 0 0 0 0 SOGE Write: Reset: 0 0 0 = Unimplemented Figure 17-19. Configuration Register 0 (CONFIG0) HSYNCOE — VSYNCO Enable This bit is set to configure the PTE1/HSYNCO pin for HSYNCO output function. Reset clears this bit. 1 = PTE1/HSYNCO pin configured as HSYNCO pin 0 = PTE1/HSYNCO pin configured as standard I/O pin VSYNCOE — VSYNCO Enable This bit is set to configure the PTE2/VSYNCO pin for VSYNCO output function. Reset clears this bit. 1 = PTE2/VSYNCO pin configured as VSYNCO pin 0 = PTE2/VSYNCO pin configured as standard I/O pin SOGE — SOG Enable This bit is set to configure the PTE0/SOG/TCH0 pin for SOG output function. Reset clears this bit. 1 = PTE0/SOG/TCH0 pin configured as SOG pin 0 = PTE0/SOG/TCH0 pin configured as standard I/O or TCH0 pin. TCH0 function is configured by ELS0B and ELS0A bits in TSC0 (bits 3 and 2 in $0010). Data Sheet 250 MC68HC908BD48 — Rev. 2.0 Input/Output (I/O) Ports MOTOROLA Data Sheet – MC68HC908BD48 Section 18. External Interrupt (IRQ) 18.1 Contents 18.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251 18.3 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251 18.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .252 18.5 IRQ Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 254 18.6 IRQ Module During Break Interrupts . . . . . . . . . . . . . . . . . . . 255 18.7 IRQ Status and Control Register . . . . . . . . . . . . . . . . . . . . . . 255 18.2 Introduction The IRQ (external interrupt) module provides a maskable interrupt input. 18.3 Features Features of the IRQ module include: • A dedicated external interrupt pin (IRQ) • IRQ interrupt control bits • Hysteresis buffer • Programmable edge-only or edge and level interrupt sensitivity • Automatic interrupt acknowledge • Internal pullup resistor MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet External Interrupt (IRQ) 251 External Interrupt (IRQ) 18.4 Functional Description A logic 0 applied to the external interrupt pin can latch a CPU interrupt request. Figure 18-1 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 latch that caused the vector fetch. • Software clear — Software can clear an interrupt latch by writing to the appropriate acknowledge bit in the interrupt status and control register (INTSCR). 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 falling-edge and low-leveltriggered. The MODE bit in the INTSCR controls the triggering sensitivity of the IRQ pin. When an interrupt pin is edge-triggered only, the interrupt remains set until a vector fetch, software clear, or reset occurs. When an interrupt pin is both falling-edge and low-level-triggered, the interrupt remains set until both of the following occur: • Vector fetch or software clear • Return of the interrupt pin to logic 1 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 INTSCR mask all external interrupt requests. A latched interrupt request is not presented to the interrupt priority logic unless the IMASK bit is clear. Data Sheet 252 MC68HC908BD48 — Rev. 2.0 External Interrupt (IRQ) MOTOROLA External Interrupt (IRQ) Functional Description NOTE: The interrupt mask (I) in the condition code register (CCR) masks all interrupt requests, including external interrupt requests. INTERNAL ADDRESS BUS ACK RESET TO CPU FOR BIL/BIH INSTRUCTIONS VECTOR FETCH DECODER VDD INTERNAL PULLUP DEVICE VDD IRQF D IRQ CLR Q SYNCHRONIZER CK IRQ INTERRUPT REQUEST IRQ FF IMASK MODE TO MODE SELECT LOGIC HIGH VOLTAGE DETECT Figure 18-1. IRQ Module Block Diagram Table 18-1. IRQ I/O Register Summary Addr. $001E Register Name Read: IRQ Status and Control Write: Register (INTSCR) Reset: Bit 7 6 5 4 3 2 0 0 0 0 IRQF 0 ACK 0 0 0 0 0 0 1 Bit 0 IMASK MODE 0 0 = Unimplemented MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet External Interrupt (IRQ) 253 External Interrupt (IRQ) 18.5 IRQ Pin 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 (INTSCR). 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 another interrupt request. If the IRQ mask bit, IMASK, is clear, the CPU loads the program counter with the vector address at locations $FFFA and $FFFB. • Return of the IRQ pin to logic 1 — As long as the IRQ pin is at logic 0, IRQ remains active. The vector fetch or software clear and the return of the IRQ pin to logic 1 may occur in any order. The interrupt request remains pending as long as the IRQ pin is at logic 0. 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 INTSCR 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. Use the BIH or BIL instruction to read the logic level on the IRQ pin. Data Sheet 254 MC68HC908BD48 — Rev. 2.0 External Interrupt (IRQ) MOTOROLA External Interrupt (IRQ) IRQ Module During Break Interrupts NOTE: When using the level-sensitive interrupt trigger, avoid false interrupts by masking interrupt requests in the interrupt routine. 18.6 IRQ Module During Break Interrupts The BCFE bit in the SIM break flag control register (SBFCR) enables software to clear the latch during the break state. See Section 20. Break Module (BRK). 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 CPU interrupt flags 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 interrupt flags. 18.7 IRQ Status and Control Register The IRQ status and control register (INTSCR) controls and monitors operation of the IRQ module. The INTSCR: • Shows the state of the IRQ flag • Clears the IRQ latch • Masks IRQ interrupt request • Controls triggering sensitivity of the IRQ interrupt pin MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet External Interrupt (IRQ) 255 External Interrupt (IRQ) Address: $001E Bit 7 6 5 4 Read: 3 2 IRQF 0 Write: Reset: 1 Bit 0 IMASK MODE 0 0 ACK 0 0 0 0 0 0 = Unimplemented Figure 18-2. IRQ Status and Control Register (INTSCR) IRQF — IRQ Flag Bit 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 0 = IRQ interrupt requests on falling edges only Data Sheet 256 MC68HC908BD48 — Rev. 2.0 External Interrupt (IRQ) MOTOROLA Data Sheet – MC68HC908BD48 Section 19. Computer Operating Properly (COP) 19.1 Contents 19.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257 19.3 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .258 19.4 I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259 19.4.1 OSCXCLK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .259 19.4.2 STOP Instruction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259 19.4.3 COPCTL Write . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .259 19.4.4 Power-On Reset. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259 19.4.5 Internal Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260 19.4.6 Reset Vector Fetch. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260 19.4.7 COPD (COP Disable). . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260 19.4.8 COPRS (COP Rate Select) . . . . . . . . . . . . . . . . . . . . . . . . 260 19.5 COP Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261 19.6 Interrupts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .261 19.7 Monitor Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .261 19.8 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261 19.8.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .262 19.8.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .262 19.9 COP Module During Break Mode . . . . . . . . . . . . . . . . . . . . . . 262 19.2 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. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Computer Operating Properly (COP) 257 Computer Operating Properly (COP) 19.3 Functional Description Figure 19-1 shows the structure of the COP module. RESET CIRCUIT RESET STATUS REGISTER COP TIMEOUT CLEAR STAGES 5–12 STOP INSTRUCTION INTERNAL RESET SOURCES RESET VECTOR FETCH CLEAR ALL STAGES 12-BIT COP PRESCALER OSCXCLK COPCTL WRITE COP CLOCK COP MODULE 6-BIT COP COUNTER COPEN (FROM SIM) COP DISABLE (COPD FROM CONFIG1) RESET COPCTL WRITE CLEAR COP COUNTER COP RATE SEL (COPRS FROM CONFIG1) Figure 19-1. COP Block Diagram The COP counter is a free-running 6-bit counter preceded by a 12-bit prescaler 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 configuration register 1. With a 218 – 24 OSCXCLK cycle overflow option, a 24MHz crystal gives a COP timeout period of 10.922ms. 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 prescaler. 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. Data Sheet 258 MC68HC908BD48 — Rev. 2.0 Computer Operating Properly (COP) MOTOROLA Computer Operating Properly (COP) I/O Signals A COP reset pulls the RST pin low for 32 OSCXCLK cycles and sets the COP bit in the SIM reset status register (SRSR). In monitor mode, the COP is disabled if the RST pin or the IRQ1 is held at VTST. During the break state, VTST 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. 19.4 I/O Signals The following paragraphs describe the signals shown in Figure 19-1. 19.4.1 OSCXCLK OSCXCLK is the crystal oscillator output signal. OSCXCLK frequency is equal to the crystal frequency. 19.4.2 STOP Instruction The STOP instruction clears the COP prescaler. 19.4.3 COPCTL Write Writing any value to the COP control register (COPCTL) (see 19.5 COP Control Register) clears the COP counter and clears bits 12 through 5 of the prescaler. Reading the COP control register returns the low byte of the reset vector. 19.4.4 Power-On Reset The power-on reset (POR) circuit clears the COP prescaler 4096 OSCXCLK cycles after power-up. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Computer Operating Properly (COP) 259 Computer Operating Properly (COP) 19.4.5 Internal Reset An internal reset clears the COP prescaler and the COP counter. 19.4.6 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. 19.4.7 COPD (COP Disable) The COPD signal reflects the state of the COP disable bit (COPD) in the configuration register 1 (see Figure 19-2). 19.4.8 COPRS (COP Rate Select) The COPRS signal reflects the state of the COP rate select bit (COPRS) in the configuration register 1(see Figure 19-2). Address: Read: $001F Bit 7 6 5 4 0 0 0 0 3 2 1 Bit 0 SSREC COPRS STOP COPD 0 0 0 0 Write: Reset: 0 0 0 0 = Unimplemented Figure 19-2. Configuration Register 1 (CONFIG1) COPRS — COP Rate Select Bit COPRS selects the COP timeout period. Reset clears COPRS. 1 = COP timeout period = 213 – 24 OSCXCLK cycles 0 = COP timeout period = 218 – 24 OSCXCLK cycles COPD — COP Disable Bit COPD disables the COP module. 1 = COP module disabled 0 = COP module enabled Data Sheet 260 MC68HC908BD48 — Rev. 2.0 Computer Operating Properly (COP) MOTOROLA Computer Operating Properly (COP) COP Control Register 19.5 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 19-3. COP Control Register (COPCTL) 19.6 Interrupts The COP does not generate CPU interrupt requests. 19.7 Monitor Mode When monitor mode is entered with VTST on the IRQ pin, the COP is disabled as long as VTST remains on the IRQ pin or the RST pin. When monitor mode is entered by having blank reset vectors and not having VTST on the IRQ pin, the COP is automatically disabled until a POR occurs. 19.8 Low-Power Modes The WAIT and STOP instructions put the MCU in low powerconsumption standby modes. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Computer Operating Properly (COP) 261 Computer Operating Properly (COP) 19.8.1 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. 19.8.2 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. To prevent inadvertently turning off the COP with a STOP instruction, a configuration option is available that disables the STOP instruction. When the STOP bit in the configuration register has the STOP instruction is disabled, execution of a STOP instruction results in an illegal opcode reset. 19.9 COP Module During Break Mode The COP is disabled during a break interrupt when VTST is present on the RST pin. Data Sheet 262 MC68HC908BD48 — Rev. 2.0 Computer Operating Properly (COP) MOTOROLA Data Sheet – MC68HC908BD48 Section 20. Break Module (BRK) 20.1 Contents 20.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263 20.3 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264 20.4 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .264 20.4.1 Flag Protection During Break Interrupts . . . . . . . . . . . . . . . 266 20.4.2 CPU During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . .266 20.4.3 TIM During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . . 266 20.4.4 COP During Break Interrupts . . . . . . . . . . . . . . . . . . . . . . . 266 20.5 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266 20.5.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .266 20.5.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .267 20.6 Break Module Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267 20.6.1 Break Status and Control Register. . . . . . . . . . . . . . . . . . . 267 20.6.2 Break Address Registers . . . . . . . . . . . . . . . . . . . . . . . . . . 268 20.6.3 SIM Break Status Register . . . . . . . . . . . . . . . . . . . . . . . . . 268 20.6.4 SIM Break Flag Control Register . . . . . . . . . . . . . . . . . . . . 270 20.2 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. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Break Module (BRK) 263 Break Module (BRK) 20.3 Features Features of the break module include: • Accessible input/output (I/O) registers during the break interrupt • CPU-generated break interrupts • Software-generated break interrupts • COP disabling during break interrupts 20.4 Functional Description When the internal address bus matches the value written in the break address registers, the break module issues a breakpoint signal to the CPU. The CPU then loads 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). The following 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 20-1 shows the structure of the break module. Data Sheet 264 MC68HC908BD48 — Rev. 2.0 Break Module (BRK) MOTOROLA Break Module (BRK) Functional Description IAB15–IAB8 BREAK ADDRESS REGISTER HIGH 8-BIT COMPARATOR IAB15–IAB0 BREAK CONTROL 8-BIT COMPARATOR BREAK ADDRESS REGISTER LOW IAB7–IAB0 Figure 20-1. Break Module Block Diagram Table 20-1. Break Module I/O Register Summary Addr. Register Name Read: SIM Break Status Register $FE00 Write: (SBSR) Reset: $FE03 $FE0C $FE0D Read: SIM Break Flag Control Write: Register (SBFCR) Reset: Read: Break Address Register Write: High (BRKH) Reset: Read: Break Address Register Write: Low (BRKL) Reset: Read: Break Status and Control $FE0E Write: Register (BRKSCR) Reset: Note: Writing a logic 0 clears SBSW. Bit 7 6 5 4 3 2 R R R R R R 0 0 0 0 0 0 0 0 BCFE R R R R R R R Bit 15 14 13 12 11 10 9 Bit 8 0 0 0 0 0 0 0 0 Bit 7 6 5 4 3 2 1 Bit 0 0 0 0 0 0 0 0 0 BRKE BRKA 0 0 0 0 0 0 0 0 0 0 0 0 0 0 SBSW Note Bit 0 R 0 = Unimplemented MC68HC908BD48 — Rev. 2.0 MOTOROLA 1 R = Reserved Data Sheet Break Module (BRK) 265 Break Module (BRK) 20.4.1 Flag Protection During Break Interrupts The BCFE bit in the SIM break flag control register (SBFCR) enables software to clear status bits during the break state. 20.4.2 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. 20.4.3 TIM During Break Interrupts A break interrupt stops the timer counters. 20.4.4 COP During Break Interrupts The COP is disabled during a break interrupt when VTST is present on the RST pin. 20.5 Low-Power Modes The WAIT and STOP instructions put the MCU in low powerconsumption standby modes. 20.5.1 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 Section 7. System Integration Module (SIM)). Clear the SBSW bit by writing logic 0 to it. Data Sheet 266 MC68HC908BD48 — Rev. 2.0 Break Module (BRK) MOTOROLA Break Module (BRK) Break Module Registers 20.5.2 Stop Mode A break interrupt causes exit from stop mode and sets the SBSW bit in the break status register. 20.6 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) • SIM Break status register (SBSR) • SIM Break flag control register (SBFCR) 20.6.1 Break Status and Control Register The break status and control register (BRKSCR) 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 20-2. 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 on 16-bit address match MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Break Module (BRK) 267 Break Module (BRK) 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 = (When read) Break address match 0 = (When read) No break address match 20.6.2 Break Address Registers The break address registers (BRKH and BRKL) 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 20-3. 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 20-4. Break Address Register Low (BRKL) 20.6.3 SIM Break Status Register The SIM break status register (SBSR) contains a flag to indicate that a break caused an exit from wait mode. The flag is useful in applications requiring a return to wait mode after exiting from a break interrupt. Data Sheet 268 MC68HC908BD48 — Rev. 2.0 Break Module (BRK) MOTOROLA Break Module (BRK) Break Module Registers Address: $FE00 Bit 7 6 5 4 3 2 R R R R R R Read: Bit 0 SBSW Write: Reset: 1 R Note 0 0 Note: Writing a logic 0 clears SBSW. 0 0 R = Reserved 0 0 0 0 Figure 20-5. SIM Break Status Register (SBSR) SBSW — SIM Break Stop/Wait Bit 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 SBSW can be read within the break interrupt routine. The user can modify the return address on the stack by subtracting one from it. The following code is an example. ; 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,SBSR, 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. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Break Module (BRK) 269 Break Module (BRK) 20.6.4 SIM Break Flag Control Register The SIM break flag control register (SBFCR) 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 20-6. SIM Break Flag Control Register (SBFCR) 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 Data Sheet 270 MC68HC908BD48 — Rev. 2.0 Break Module (BRK) MOTOROLA Data Sheet – MC68HC908BD48 Section 21. Electrical Specifications 21.1 Contents 21.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271 21.3 Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . 272 21.4 Functional Operating Range. . . . . . . . . . . . . . . . . . . . . . . . . . 273 21.5 Thermal Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273 21.6 DC Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . 274 21.7 Control Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275 21.8 Oscillator Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275 21.9 ADC Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276 21.10 USB DC Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . 277 21.11 USB Low Speed Source Electrical Characteristics. . . . . . . . . 278 21.12 Timer Interface Module Characteristics . . . . . . . . . . . . . . . . . 278 21.13 DDC12AB/MMIIC Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . 279 21.13.1 DDC12AB/MMIIC Interface Input Signal Timing . . . . . . . . 279 21.13.2 DDC12AB/MMIIC Interface Output Signal Timing . . . . . . . 279 21.14 Sync Processor Timing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 280 21.15 Memory Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 281 21.2 Introduction This section contains electrical and timing specifications. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Electrical Specifications 271 Electrical Specifications 21.3 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 21.6 DC Electrical Characteristics for guaranteed operating conditions. Characteristic Symbol Value Unit Supply Voltage VDD –0.3 to +5.5 V Input Voltage VIN VSS –0.3 to VDD +0.3 V I ±25 mA Storage Temperature TSTG –55 to +150 °C Maximum Current Out of VSS IMVSS 100 mA Maximum Current Into VDD IMVDD 100 mA Maximum Current Per Pin Excluding VDD and VSS NOTE: 1. Voltages referenced to VSS. NOTE: 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) ≤ VDD. Reliability of operation is enhanced if unused inputs are connected to an appropriate logic voltage level (for example, either VSS or VDD.) Data Sheet 272 MC68HC908BD48 — Rev. 2.0 Electrical Specifications MOTOROLA Electrical Specifications Functional Operating Range 21.4 Functional Operating Range Characteristic Symbol Value Unit TA 0 to 85 °C VDD 4.5 to 5.5 V Symbol Value Unit Thermal Resistance QFP (44 Pins) SDIP (42 Pins) θJA 95 60 °C/W 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 PD × (TA + 273 °C) + PD2 × θJA W/°C Average Junction Temperature TJ TA + (PD × θJA) °C TJM 100 °C Operating Temperature Range Operating Voltage Range 21.5 Thermal Characteristics Characteristic Maximum Junction Temperature 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. MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Electrical Specifications 273 Electrical Specifications 21.6 DC Electrical Characteristics Symbol Min Typ(2) Max Unit Output High Voltage (ILOAD = –2.0mA) All ports (except PTD0 and PTD1) VOH VDD – 0.8 — — V Output Low Voltage (ILOAD = 1.6mA) All ports (except PTD0 and PTD1) VOL — — 0.4 V Input High Voltage All ports (except PTD0 and PTD1), IRQ, RST OSC1, PTD0, PTD1 VSYNC, HSYNC VIH 0.7 × VDD 0.7 × VREG 2.0 — — — VDD VREG VDD V V Input Low Voltage All ports (except PTD0 and PTD1), IRQ, RST OSC1, PTD0, PTD1 VSYNC, HSYNC VIL VSS VSS VSS — — — 0.2 × VDD 0.2 × VREG 0.8 V V VDD Supply Current Run, USB active Run, USB suspended(3) Wait (4) Stop(5) 0°C to 85°C IDD — — — — 10 8 4 2 15 12 8 5 mA mA mA mA I/O Ports Hi-Z Leakage Current IIL — — ±10 µA Input Current IIN — — ±1 µA COUT CIN — — — — 12 8 pF VPOR 0 — 100 mV POR Rise Time Ramp Rate RPOR 0.035 — — V/ms Monitor Mode Entry Voltage VTST VDD + 2.5 9 V Pull-up Resistor RST, IRQ RPU 20 45 65 kΩ Low-Voltage Inhibit, trip falling voltage VTRIPF 3.4 3.6 3.8 V Low-Voltage Inhibit, trip rising voltage VTRIPR 3.6 3.8 4.0 V VHYS — 200 — mV Characteristic Capacitance Ports (as Input or Output) POR ReArm Voltage(6) (7) Low-Voltage Inhibit Reset/Recover Hysteresis NOTES: 1. VDD = 5.0 Vdc ± 10%, 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. All inputs 0.2 V from rail. No dc loads. Less than 100 pF on all outputs. CL = 15 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 (fOSCXCLK = 24MHz); all inputs 0.2 V from rail; no dc loads; less than 100 pF on all outputs. CL = 15pF on OSC2; USB in suspend mode, 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, 1.5 KΩ ± 1% pull-up resistor on D+ pin and 15 KΩ ± 1% pull-down resistors on D+ and D– pins, no port pins sourcing current. 6. Maximum is highest voltage that POR is guaranteed. 7. If minimum VDD is not reached before the internal POR reset is released, RST must be driven low externally until minimum VDD is reached. Data Sheet 274 MC68HC908BD48 — Rev. 2.0 Electrical Specifications MOTOROLA Electrical Specifications Control Timing 21.7 Control Timing Characteristic Symbol Min Max Unit Internal Operating Frequency(2) fOP — 6 MHz RST Input Pulse Width Low(3) tIRL 50 — ns NOTES: 1. VDD = 4.5 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. 21.8 Oscillator Characteristics Characteristic Symbol Min Typ Max Unit Crystal Frequency(1) fOSCXCLK — 24 — MHz External Clock Reference Frequency(1), (2) fOSCXCLK dc — 24 MHz Crystal Load Capacitance(3) CL — 30 — pF (3) C1 — 15 — pF Crystal Tuning Capacitance(3) C2 — 15 — pF Feedback Bias Resistor RB — 10 — MΩ Series Resistor(3), (4) RS — — — Crystal Fixed Capacitance NOTES: 1. The sync processor module is designed to function at fOSCXCLK = 24MHz. The values given here are oscillator specifications. 2. No more than 10% duty cycle deviation from 50% 3. Quoted values are for reference only. Actual values depend on application and crystal performance. Please consult crystal vendor data sheet 4. Not Required for high frequency crystals MC68HC908BD48 — Rev. 2.0 MOTOROLA Data Sheet Electrical Specifications 275 Electrical Specifications 21.9 ADC Characteristics Characteristic(1) Symbol Min Max Unit Supply voltage VDDAD 4.5 (VDD min) 5.5 (VDD max) V Input voltages VADIN 0 ------ VDD 2 3 V Resolution BAD 8 8 Bits Absolute accuracy (VSS = 0 V, VDD = 5 V ± 10%) AAD — ±2 LSB Includes quantization ADC internal clock fADIC 0.375 6 MHz tAIC = 1/fADIC, tested only at 1.5 MHz Conversion range RAD VSS ------ VDD V Power-up time tADPU 16 Conversion time tADC 12 13 tAIC cycles Sample time(2) tADS 4 — tAIC cycles Zero input reading(3) ZADI 00 02 Hex Full-scale reading(3) FADI FD FF Hex Input capacitance CADI — 8 pF — — ±1 µA Input leakage(4) Port C 2 3 Comments tAIC cycles Not tested NOTES: 1. VDD = 5.0 Vdc ± 10%, VSS = 0 Vdc, TA = TL to TH, unless otherwise noted. 2. Source impedances greater than 10 kΩ adversely affect internal RC charging time during input sampling. 3. Zero-input/full-scale reading requires sufficient decoupling measures for accurate conversions. 4. The external system error caused by input leakage current is approximately equal to the product of R source and input current. Data Sheet 276 MC68HC908BD48 — Rev. 2.0 Electrical Specifications MOTOROLA Electrical Specifications USB DC Electrical Characteristics Input Voltage, ADIN VDD = 5V @ 25°C, ADC Clock = 1.5MHz Offset is typically 22mV Steps Figure 21-1. ADC Input Voltage vs. Step Readings 21.10 USB DC Electrical Characteristics Characteristic Symbol Conditions Min Hi-Z State Data Line Leakage ILO 0V