MC908GR32AVFAE Datasheet, PDF (93/314 Pages) Freescale Semiconductor, Inc – Microcontrollers

Chapter 6
Computer Operating Properly (COP) Module
6.1 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.
6.2 Functional Description
Figure 6-1 shows the structure of the COP module.
CGMXCLK
12-BIT SIM COUNTER
RESET CIRCUIT
RESET STATUS REGISTER
STOP INSTRUCTION
INTERNAL RESET SOURCES
COPCTL WRITE
COPEN (FROM SIM)
COP DISABLE
(FROM CONFIG)
RESET
COPCTL WRITE
COP RATE SEL
(FROM CONFIG)
COP CLOCK
COP MODULE
6-BIT COP COUNTER
CLEAR
COP COUNTER
Figure 6-1. COP Block Diagram
MC68HC908GR60A • MC68HC908GR48A • MC68HC908GR32A Data Sheet, Rev. 5
Freescale Semiconductor
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