AXIOMTEK SBC8232, User Manual

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SBC8232 386SX ISA Half-size CPU Card Family User’s Manual
Watchdog Timer
23
A p p e n d i x A
Watchdog Timer
Watchdog Timer Configuration
The watchdog timer will reset the system automatically once
the system program fails to refresh the watchdog timer during
the watchdog time out interval. It is defined at I/O port 0443H
and 043H to enable/disable watchdog time out function.
To operate the watchdog function, user must have a program
to set the watchdog time out value, and refresh the watchdog
timer cycle. If the system program goes into a dead loop or
operates at an abnormal cycle, the watchdog timer cannot be
refreshed immediately. Meanwhile, the system will be reset by
watchdog timer automatically. The watchdog timer will be
refresh by
disable watchdog output then enable watchdog
output
The following examples show the normal structure of system
program.