MC908JL8CDWE Datasheet, PDF (173/212 Pages) Freescale Semiconductor, Inc – Microcontrollers

Chapter 14
Computer Operating Properly (COP)
14.1 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.
14.2 Functional Description
Figure 14-1 shows the structure of the COP module.
SIM
ICLK
12-BIT SIM COUNTER
SIM RESET CIRCUIT
RESET STATUS REGISTER
INTERNAL RESET SOURCES⁽¹⁾
RESET VECTOR FETCH
COPCTL WRITE
COPEN (FROM SIM)
COPD (FROM CONFIG1)
RESET
COPCTL WRITE
COP RATE SEL
(COPRS FROM CONFIG1)
COP CLOCK
COP MODULE
6-BIT COP COUNTER
CLEAR
COP COUNTER
NOTE: See SIM section for more details.
Figure 14-1. COP Block Diagram
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor
173