MC68HC908GR8CD Freescale Semiconductor, MC68HC908GR8CD Datasheet - Page 93

• Manufacturer Part Number: MC68HC908GR8CD
• Description: 8-bit Microcontrollers - MCU 8 Bit 8MHz
• Manufacturer: Freescale Semiconductor

Specifications of MC68HC908GR8CD

• Product Category: 8-bit Microcontrollers - MCU
• Rohs: yes
• Core: HC08
• Data Bus Width: 8 bit
• Maximum Clock Frequency: 8 MHz
• Program Memory Size: 64 KB
• Data Ram Size: 384 B
• Operating Supply Voltage: 3 V to 5 V
• Package / Case: SOIC-28
• Mounting Style: SMD/SMT
• Data Rom Size: 64 KB
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: - 40 C
• Number Of Programmable I/os: 21
• Program Memory Type: Flash

Chapter 9
Computer Operating Properly (COP)
9.1 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.
9.2 Functional Description
Figure 9-1
Freescale Semiconductor
INTERNAL RESET SOURCES
shows the structure of the COP module.
RESET VECTOR FETCH
STOP INSTRUCTION
COPEN (FROM SIM)
(FROM CONFIG)
COP RATE SEL
(FROM CONFIG)
COPCTL WRITE
COPCTL WRITE
COP DISABLE
CGMXCLK
RESET
MC68HC908GR8 • MC68HC908GR4 Data Sheet, Rev. 7
COP MODULE
COP CLOCK
12-BIT COP PRESCALER
Figure 9-1. COP Block Diagram
COP COUNTER
6-BIT COP COUNTER
CLEAR
RESET STATUS REGISTER
RESET CIRCUIT
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