MC908JL3ECPE Datasheet, PDF (123/180 Pages) Freescale Semiconductor, Inc – Microcontrollers

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
Figure 13-1 shows the structure of the COP module.
2OSCOUT
SIM
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 SEL
(COPRS FROM CONFIG1)
COP MODULE
6-BIT COP COUNTER
CLEAR
COP COUNTER
NOTE: See Chapter 5 System Integration Module (SIM) for more details.
Figure 13-1. COP Block Diagram
MC68HC908JL3E Family Data Sheet, Rev. 4
Freescale Semiconductor
123