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MC68HC908GZ16 Datasheet, PDF (85/314 Pages) Motorola, 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.
BUSCLKX4
SIM MODULE
12-BIT SIM COUNTER
SIM RESET CIRCUIT
RESET STATUS REGISTER
INTERNAL RESET SOURCES(1)
RESET VECTOR FETCH
COPCTL WRITE
COP CLOCK
COPEN (FROM SIM)
COPD (FROM CONFIG1)
RESET
COPCTL WRITE
COP RATE SELECT
(COPRS FROM CONFIG1)
COP MODULE
6-BIT COP COUNTER
CLEAR
COP COUNTER
1. See Chapter 16 System Integration Module (SIM) for more details.
Figure 6-1. COP Block Diagram
MC68HC908GZ16 • MC68HC908GZ8 Data Sheet, Rev. 1
Freescale Semiconductor
85