Contec BX710 Series User Manual page 110

How to Use the Watchdog Timer
BIOS setting
Power ON
Set event
output control
Instruct
WDT to stop
Set timer value
Start & clear WDT
Application
NO
Modify timer
value?
*WDT: Watch Dog Timer
Figure 5.5. How to Use the Watchdog Timer
Example usage
Out 4004h 01h
In 4002h
Out 4003h 0Fh
Out 4002h A5h
In 4002h
BX710 series User's Manual
Output data to ports 4001h and 4004h to set the counter clock.
...
Read port 4002h, stop the WDT, and turn off alarm output.
...
...
Output set data to port 4003h.
Output of A5h to port 4002h starts the WDT and output
...
of A5h to the same port clears the timer.
To modify the timer value during operation, the WDT
...
needs to be stopped temporarily.
YES
: To assign IRQ5 to the event whose time-up value is 15sec:
: Set the event at the time of WDT expiration to IRQ5.
: Stop the WDT timer and cancel the alarm.
: Set the WDT expiration time to 15sec.
: Start and clear the WDT.
: Stop the WDT and cancel the alarm.
5. Each Component Function
103