Datasheet
Table Of Contents
- List of Sections
- Table of Contents
- List of Figures
- List of Tables
- Section 1. General Description
- 1.1 Contents
- 1.2 Introduction
- 1.3 Features
- 1.4 MCU Block Diagram
- 1.5 Pin Assignments
- 1.6 Pin Functions
- 1.6.1 Power Supply Pins (Vdd and Vss)
- 1.6.2 Oscillator Pins (OSC1 and OSC2)
- 1.6.3 External Reset Pin (RST)
- 1.6.4 External Interrupt Pin (IRQ)
- 1.6.5 Analog Power Supply Pin (VDDA)
- 1.6.6 Analog Ground Pin (VSSA)
- 1.6.7 Analog Ground Pin (AVSS/VREFL)
- 1.6.8 ADC Voltage Reference Pin (VREFH)
- 1.6.9 Analog Supply Pin (VDDAREF)
- 1.6.10 External Filter Capacitor Pin (CGMXFC)
- 1.6.11 Port A Input/Output (I/O) Pins (PTA7-PTA0)
- 1.6.12 Port B I/O Pins (PTB7/ATD7-PTB0/ATD0)
- 1.6.13 Port C I/O Pins (PTC5-PTC0)
- 1.6.14 Port D I/O Pins (PTD7-PTD0)
- 1.6.15 Port E I/O Pins (PTE7/SPSCK-PTE0/TxD)
- 1.6.16 Port F I/O Pins (PTF7-PTF0/TACH2)
- 1.6.17 Port G I/O Pins (PTG2/KBD2-PTG0/KBD0)
- 1.6.18 Port H I/O Pins (PTH1/KBD4-PTH0/KBD3)
- 1.7 I/O Pin Summary
- 1.8 Signal Name Conventions
- 1.9 Clock Source Summary
- Section 2. Memory Map
- Section 3. Random-Access Memory (RAM)
- Section 4. FLASH Memory
- Section 5. EEPROM
- Section 6. Configuration Register (CONFIG)
- Section 7. Central Processor Unit (CPU)
- Section 8. System Integration Module (SIM)
- Section 9. Clock Generator Module (CGM)
- 9.1 Contents
- 9.2 Introduction
- 9.3 Features
- 9.4 Functional Description
- 9.5 I/O Signals
- 9.5.1 Crystal Amplifier Input Pin (OSC1)
- 9.5.2 Crystal Amplifier Output Pin (OSC2)
- 9.5.3 External Filter Capacitor Pin (CGMXFC)
- 9.5.4 PLL Analog Power Pin (VDDA)
- 9.5.5 Oscillator Enable Signal (SIMOSCEN)
- 9.5.6 Crystal Output Frequency Signal (CGMXCLK)
- 9.5.7 CGM Base Clock Output (CGMOUT)
- 9.5.8 CGM CPU Interrupt (CGMINT)
- 9.6 CGM Registers
- 9.7 Interrupts
- 9.8 Low-Power Modes
- 9.9 CGM During Break Interrupts
- 9.10 Acquisition/Lock Time Specifications
- Section 10. Monitor ROM (MON)
- Section 11. Timer Interface Module A (TIMA)
- Section 12. Timer Interface Module B (TIMB)
- Section 13. Programmable Interrupt Timer (PIT)
- Section 14. Analog-to-Digital Converter (ADC)
- Section 15. Serial Communications Interface Module (SCI)
- Section 16. Serial Peripheral Interface Module (SPI)
- 16.1 Contents
- 16.2 Introduction
- 16.3 Features
- 16.4 Pin Name Conventions and I/O Register Addresses
- 16.5 Functional Description
- 16.6 Transmission Formats
- 16.7 Queuing Transmission Data
- 16.8 Error Conditions
- 16.9 Interrupts
- 16.10 Resetting the SPI
- 16.11 Low-Power Modes
- 16.12 SPI During Break Interrupts
- 16.13 I/O Signals
- 16.14 I/O Registers
- Section 17. Input/Output (I/O) Ports
- Section 18. External Interrupt (IRQ)
- Section 19. Keyboard Interrupt Module (KBI)
- Section 20. Computer Operating Properly (COP)
- Section 21. Low-Voltage Inhibit (LVI)
- Section 22. Break Module (BRK)
- Section 23. Electrical Specifications
- 23.1 Contents
- 23.2 Introduction
- 23.3 Absolute Maximum Ratings
- 23.4 Functional Operating Range
- 23.5 Thermal Characteristics
- 23.6 5.0-V DC Electrical Characteristics
- 23.7 EEPROM and Memory Characteristics
- 23.8 5.0-V Control Timing
- 23.9 Timer Interface Module Characteristics
- 23.10 ADC Characteristics
- 23.11 SPI Characteristics
- 23.12 Clock Generation Module Characteristics
- 23.13 FLASH Memory Characteristics
- Section 24. Mechanical Specifications
- Section 25. Ordering Information
System Integration Module (SIM)
Technical Data MC68HC908AB32 — Rev. 1.1
118 System Integration Module (SIM) Freescale Semiconductor
8.5.1 SIM Counter during Power-On Reset
The power-on reset (POR) module detects power applied to the MCU.
At power-on, the POR circuit asserts the signal PORRST. Once the SIM
is initialized, it enables the clock generation module (CGM) to drive the
bus clock state machine.
8.5.2 SIM Counter during Stop Mode Recovery
The SIM counter is also used for stop mode recovery. The STOP
instruction clears the SIM counter. After an interrupt, break, or reset, the
SIM senses the state of the short STOP recovery bit, SSREC, in the
configuration register 1 (CONFIG1). If the SSREC bit is a logic 1, then
the stop recovery is reduced from the normal delay of 4096 CGMXCLK
cycles down to 32 CGMXCLK 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.
8.5.3 SIM Counter and Reset States
External reset has no effect on the SIM counter. (See 8.7.2 Stop Mode
for details.) The SIM counter is free-running after all reset states. (See
8.4.2 Active Resets from Internal Sources for counter control and
internal reset recovery sequences.)
8.6 Exception Control
Normal, sequential program execution can be changed in three different
ways:
• Interrupts
– Maskable hardware CPU interrupts
– Non-maskable software interrupt instruction (SWI)
• Reset
• Break interrupts
