mc68hc908gt8 Freescale Semiconductor, Inc, mc68hc908gt8 Datasheet - Page 61

• Manufacturer Part Number: mc68hc908gt8
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Chapter 5
Computer Operating Properly (COP) Module
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
CONFIG register.
5.2 Functional Description
Figure 5-1
shows the structure of the COP module.
SIM MODULE
SIM RESET CIRCUIT
COPCLK
12-BIT SIM COUNTER
RESET STATUS REGISTER
INTERNAL RESET SOURCES
RESET VECTOR FETCH
COPCTL WRITE
COP CLOCK
COP MODULE
6-BIT COP COUNTER
COPEN (FROM SIM)
COPD (FROM CONFIG1)
CLEAR
RESET
COP COUNTER
COPCTL WRITE
COP RATE SELECT
(COPRS FROM CONFIG1)
Figure 5-1. COP Block Diagram
MC68HC908GT16 • MC68HC908GT8 • MC68HC08GT16 Data Sheet, Rev. 5.0
Freescale Semiconductor
61