Chapter 13
Computer Operating Properly (COP)
13.1 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
CONFIG1 register.
13.2 Functional Description
shows the structure of the COP module.
SIM
2OSCOUT
12-BIT SIM COUNTER
CLEAR STAGES 5–12
SIM RESET CIRCUIT
RESET STATUS REGISTER
CLEAR ALL STAGES
INTERNAL RESET SOURCES
(1)
RESET VECTOR FETCH
COPCTL WRITE
COP CLOCK
COP MODULE
6-BIT COP COUNTER
COPEN (FROM SIM)
COPD (FROM CONFIG1)
RESET
COPCTL WRITE
COP RATE SEL
(COPRS FROM CONFIG1)
CLEAR
COP COUNTER
NOTE: See
for more details.
Figure 13-1. COP Block Diagram
MC68HC908JL3E Family Data Sheet, Rev. 4
Freescale Semiconductor
123
COP TIMEOUT
FREESCALE [ FREESCALE SEMICONDUCTOR, INC ]
