MC68HC908QY2CDW Datasheet, PDF (57/184 Pages) Freescale Semiconductor, Inc – Microcontrollers

Chapter 6
Computer Operating Properly (COP)
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
configuration 1 (CONFIG1) register.
6.2 Functional Description
BUSCLKX4
12-BIT SIM COUNTER
RESET CIRCUIT
RESET STATUS REGISTER
STOP INSTRUCTION
INTERNAL RESET SOURCES
COPCTL WRITE
COP CLOCK
COPEN (FROM SIM)
COP DISABLE (COPD FROM CONFIG1)
RESET
COPCTL WRITE
COP RATE SELECT
(COPRS FROM CONFIG1)
6-BIT COP COUNTER
CLEAR
COP COUNTER
Figure 6-1. COP Block Diagram
MC68HC908QY/QT Family Data Sheet, Rev. 6
Freescale Semiconductor
57