Chapter 5
Computer Operating Properly (COP)
5.1 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
configuration 1 (CONFIG1) register.
5.2 Functional Description
SIM MODULE
BUSCLKX4
12-BIT SIM COUNTER
SIM RESET CIRCUIT
RESET STATUS REGISTER
CLEAR ALL STAGES
CLEAR STAGES 5–12
INTERNAL RESET SOURCES
(1)
STOP INSTRUCTION
COPCTL WRITE
COP CLOCK
COP MODULE
6-BIT COP COUNTER
COPEN (FROM SIM)
COPD (FROM CONFIG1)
RESET
COPCTL WRITE
COP RATE SELECT
(COPRS FROM CONFIG1)
CLEAR
COP COUNTER
1. See
for more details.
Figure 5-1. COP Block Diagram
MC68HC908QC16 • MC68HC908QC8 • MC68HC908QC4 Data Sheet, Rev. 5
Freescale Semiconductor
63
COP TIMEOUT
FREESCALE [ FREESCALE SEMICONDUCTOR, INC ]
