Datasheet
Table Of Contents
- Revision History
- List of Chapters
- Table of Contents
- Chapter 1 General Description
- 1.1 Introduction
- 1.2 Features
- 1.3 MCU Block Diagram
- 1.4 Pin Assignments
- 1.5 Pin Functions
- 1.5.1 Power Supply Pins (VDD and VSS)
- 1.5.2 Oscillator Pins (OSC1 and OSC2)
- 1.5.3 External Reset Pin (RST)
- 1.5.4 External Interrupt Pin (IRQ)
- 1.5.5 CGM Power Supply Pins (VDDA and VSSA)
- 1.5.6 External Filter Capacitor Pin (CGMXFC)
- 1.5.7 ADC Power Supply/Reference Pins (VDDAD/VREFH and VSSAD/VREFL)
- 1.5.8 Port A Input/Output (I/O) Pins (PTA7/KBD7/AD15-PTA0/KBD0/AD8)
- 1.5.9 Port B I/O Pins (PTB7/AD7-PTB0/AD0)
- 1.5.10 Port C I/O Pins (PTC6-PTC0)
- 1.5.11 Port D I/O Pins (PTD7/T2CH1-PTD0/SS)
- 1.5.12 Port E I/O Pins (PTE5-PTE2, PTE1/RxD, and PTE0/TxD)
- 1.5.13 Port F I/O Pins (PTF7/T2CH5-PTF0)
- 1.5.14 Port G I/O Pins (PTG7/AD23-PTBG0/AD16)
- 1.5.15 Unused Pin Termination
- Chapter 2 Memory
- 2.1 Introduction
- 2.2 Unimplemented Memory Locations
- 2.3 Reserved Memory Locations
- 2.4 Input/Output (I/O) Section
- 2.5 Random-Access Memory (RAM)
- 2.6 FLASH-1 Memory (FLASH-1)
- 2.7 FLASH-2 Memory (FLASH-2)
- Chapter 3 Analog-to-Digital Converter (ADC)
- Chapter 4 Clock Generator Module (CGM)
- 4.1 Introduction
- 4.2 Features
- 4.3 Functional Description
- 4.4 I/O Signals
- 4.4.1 Crystal Amplifier Input Pin (OSC1)
- 4.4.2 Crystal Amplifier Output Pin (OSC2)
- 4.4.3 External Filter Capacitor Pin (CGMXFC)
- 4.4.4 PLL Analog Power Pin (Vdda)
- 4.4.5 PLL Analog Ground Pin (Vssa)
- 4.4.6 Oscillator Enable Signal (SIMOSCEN)
- 4.4.7 Oscillator Enable in Stop Mode Bit (OSCENINSTOP)
- 4.4.8 Crystal Output Frequency Signal (CGMXCLK)
- 4.4.9 CGM Base Clock Output (CGMOUT)
- 4.4.10 CGM CPU Interrupt (CGMINT)
- 4.5 CGM Registers
- 4.6 Interrupts
- 4.7 Special Modes
- 4.8 Acquisition/Lock Time Specifications
- Chapter 5 Configuration Register (CONFIG)
- Chapter 6 Computer Operating Properly (COP) Module
- Chapter 7 Central Processor Unit (CPU)
- Chapter 8 External Interrupt (IRQ)
- Chapter 9 Keyboard Interrupt Module (KBI)
- Chapter 10 Low-Power Modes
- 10.1 Introduction
- 10.2 Analog-to-Digital Converter (ADC)
- 10.3 Break Module (BRK)
- 10.4 Central Processor Unit (CPU)
- 10.5 Clock Generator Module (CGM)
- 10.6 Computer Operating Properly Module (COP)
- 10.7 External Interrupt Module (IRQ)
- 10.8 Keyboard Interrupt Module (KBI)
- 10.9 Low-Voltage Inhibit Module (LVI)
- 10.10 Enhanced Serial Communications Interface Module (ESCI)
- 10.11 Serial Peripheral Interface Module (SPI)
- 10.12 Timer Interface Module (TIM1 and TIM2)
- 10.13 Timebase Module (TBM)
- 10.14 Exiting Wait Mode
- 10.15 Exiting Stop Mode
- Chapter 11 Low-Voltage Inhibit (LVI)
- Chapter 12 Input/Output (I/O) Ports
- Chapter 13 Enhanced Serial Communications Interface (ESCI) Module
- Chapter 14 System Integration Module (SIM)
- Chapter 15 Serial Peripheral Interface (SPI) Module
- Chapter 16 Timebase Module (TBM)
- Chapter 17 Timer Interface Module (TIM1)
- Chapter 18 Timer Interface Module (TIM2)
- Chapter 19 Development Support
- Chapter 20 Electrical Specifications
- 20.1 Introduction
- 20.2 Absolute Maximum Ratings
- 20.3 Functional Operating Range
- 20.4 Thermal Characteristics
- 20.5 5.0-Vdc Electrical Characteristics
- 20.6 3.3-Vdc Electrical Characteristics
- 20.7 5.0-Volt Control Timing
- 20.8 3.3-Volt Control Timing
- 20.9 Clock Generation Module (CGM) Characteristics
- 20.10 5.0-Volt ADC Characteristics
- 20.11 3.3-Volt ADC Characteristics
- 20.12 5.0-Volt SPI Characteristics
- 20.13 3.3-Volt SPI Characteristics
- 20.14 Timer Interface Module Characteristics
- 20.15 Memory Characteristics
- Chapter 21 Ordering Information and Mechanical Specifications
- Appendix A MC68HC908GR48A
- Appendix B MC68HC908GR32A
Interrupts
MC68HC908GR60A • MC68HC908GR48A • MC68HC908GR32A Data Sheet, Rev. 5
Freescale Semiconductor 213
In a slave SPI (MSTR = 0), MODF generates an SPI receiver/error CPU interrupt request if the ERRIE bit
is set. The MODF bit does not clear the SPE bit or reset the SPI in any way. Software can abort the SPI
transmission by clearing the SPE bit of the slave.
NOTE
A high on the SS
pin of a slave SPI puts the MISO pin in a high impedance
state. Also, the slave SPI ignores all incoming SPSCK clocks, even if it was
already in the middle of a transmission.
To clear the MODF flag, read the SPSCR with the MODF bit set and then write to the SPCR register. This
entire clearing mechanism must occur with no MODF condition existing or else the flag is not cleared.
15.7 Interrupts
Four SPI status flags can be enabled to generate CPU interrupt requests. See Table 15-1.
Reading the SPI status and control register with SPRF set and then reading the receive data register
clears SPRF. The clearing mechanism for the SPTE flag is always just a write to the transmit data register.
The SPI transmitter interrupt enable bit (SPTIE) enables the SPTE flag to generate transmitter CPU
interrupt requests, provided that the SPI is enabled (SPE = 1).
The SPI receiver interrupt enable bit (SPRIE) enables SPRF to generate receiver CPU interrupt requests,
regardless of the state of SPE. See Figure 15-12.
Figure 15-12. SPI Interrupt Request Generation
Table 15-1. SPI Interrupts
Flag Request
SPTE
Transmitter empty
SPI transmitter CPU interrupt request
(SPTIE = 1, SPE = 1)
SPRF
Receiver full
SPI receiver CPU interrupt request
(SPRIE = 1)
OVRF
Overflow
SPI receiver/error interrupt request
(ERRIE = 1)
MODF
Mode fault
SPI receiver/error interrupt request
(ERRIE = 1)
SPTE SPTIE
SPRFSPRIE
SPE
CPU INTERRUPT REQUEST
CPU INTERRUPT REQUEST
SPI TRANSMITTER
SPI RECEIVER/ERROR
ERRIE
MODF
OVRF
