Datasheet

General Description
MCU Block Diagram
MC68HC908GR8 — Rev 4.0 Technical Data
MOTOROLA General Description 29
Figure 1-1. MCU Block Diagram
SINGLE BRKPT BREAK
MODULE
CLOCK GENERATOR MODULE 24 INTR SYSTEM INTEGRATION
MODULE
PROGR. TIMEBASE
MODULE
MONITOR MODULE
SERIAL PERIPHERAL
1-CHANNEL TIMER INTERFACE
MODULE 2
DUAL V. LOW-VOLTAGE INHIBIT
MODULE
4-BIT KEYBOARD
ARITHMETIC/LOGIC
UNIT (ALU)
CPU
REGISTERS
M68HC08 CPU
CONTROL AND STATUS REGISTERS — 64 BYTES
MC68HC908GR8 USER FLASH — 7680 BYTES
USER RAM — 384 BYTES
MONITOR ROM — 310 BYTES
USER FLASH VECTOR SPACE — 36 BYTES
SINGLE EXTERNAL IRQ
MODULE
PORTA
DDRA
DDRD
PORTD
DDRE
PORTE
INTERNAL BUS
OSC1 OSC2
CGMXFC
* RST
* IRQ
INTERFACE MODULE
INTERRUPT MODULE
COMPUTER OPERATING
PROPERLY MODULE
PTA3/KBD3
–PTA0/KBD0 †
V
DDAD /
V
REFH
8-BIT ANALOG-TO-DIGITAL
CONVERTER MODULE
PTD6/T2CH0 † PTD5/T1CH1 † PTD4/T1CH0 † PTD3/SPSCK † PTD2/MOSI † PTD1/MISO † PTD0/SS
†
PTE1/RxD PTE0/TxD
V
SSAD
/ V
REFL
2-CHANNEL TIMER INTERFACE
MODULE 1
32-kHz OSCILLATOR
PHASE-LOCKED LOOP
SERIAL COMMUNICATIONS
INTERFACE MODULE
DATA BUS SWITCH
MODULE
MEMORY MAP
MODULE
MASK OPTION REGISTER1
MODULE
SECURITY
MODULE
POWER
V
SS
V
DD
V
SSA
V
DDA
† Ports are software configurable with pullup device if input port. ‡ Higher current drive port pins * Pin contains integrated pullup device
MONITOR MODE ENTRY
MODULE
PORTB
DDRB
PTB5/AD5–PTB0/AD0
PORTC
DDRC
PTC1–PTC0 † ‡
POWER-ON RESET
MODULE
FLASH PROGRAMMING (BURN-IN) ROM — 544 BYTES
MASK OPTION REGISTER2
MODULE
MC68HC908GR4 USER FLASH — 4096BYTES
Frees
cale Semiconductor,
I
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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