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
Enhanced Serial Communications Interface (ESCI) Module
MC68HC908GR60A • MC68HC908GR48A • MC68HC908GR32A Data Sheet, Rev. 5
172 Freescale Semiconductor
Figure 13-14. Flag Clearing Sequence
In applications that are subject to software latency or in which it is important to know which byte is lost
due to an overrun, the flag-clearing routine can check the OR bit in a second read of SCS1 after
reading the data register.
NF — Receiver Noise Flag Bit
This clearable, read-only bit is set when the ESCI detects noise on the RxD pin. NF generates an NF
CPU interrupt request if the NEIE bit in SCC3 is also set. Clear the NF bit by reading SCS1 and then
reading the SCDR. Reset clears the NF bit.
1 = Noise detected
0 = No noise detected
FE — Receiver Framing Error Bit
This clearable, read-only bit is set when a 0 is accepted as the stop bit. FE generates an ESCI error
CPU interrupt request if the FEIE bit in SCC3 also is set. Clear the FE bit by reading SCS1 with FE set
and then reading the SCDR. Reset clears the FE bit.
1 = Framing error detected
0 = No framing error detected
PE — Receiver Parity Error Bit
This clearable, read-only bit is set when the ESCI detects a parity error in incoming data. PE generates
a PE CPU interrupt request if the PEIE bit in SCC3 is also set. Clear the PE bit by reading SCS1 with
PE set and then reading the SCDR. Reset clears the PE bit.
1 = Parity error detected
0 = No parity error detected
BYTE 1
NORMAL FLAG CLEARING SEQUENCE
SCRF = 1
SCRF = 1
BYTE 2 BYTE 3 BYTE 4
SCRF = 0
SCRF = 1
SCRF = 0
SCRF = 0
BYTE 1
SCRF = 1
SCRF = 1
BYTE 2 BYTE 3 BYTE 4
DELAYED FLAG CLEARING SEQUENCE
OR = 1
SCRF = 1
OR = 1
SCRF = 0
OR = 1
SCRF = 0
OR = 0
READ SCS1
SCRF = 1
OR = 0
READ SCS1
SCRF = 1
OR = 0
READ SCS1
SCRF = 1
OR = 0
READ SCDR
BYTE 1
READ SCDR
BYTE 2
READ SCDR
BYTE 3
READ SCS1
SCRF = 1
OR = 0
READ SCS1
SCRF = 1
OR = 1
READ SCDR
BYTE 1
READ SCDR
BYTE 3
