AXIOMTEK tBOX311-820-FL Series, User Manual

Page: 77 / 88

tBOX311-820-FL Series User
’
s Manual
Watchdog Timer
69
;Disable WDT:
mov
dx,2Eh
mov al,30h
out dx,al
mov dx,2Fh
mov al, 00h ;Can be disable at ant time
out dx,al
Note :
When
N’s value is 00h, the time base is set second.
M = 00: Time-out Disable
01: Time-out occurs after 1 second
02: Time-out occurs after 2 seconds
03: Time-out occurs after 3 seconds
FF: Time-out occurs after 255 seconds
Sample of Watchdog application
Assume there is program A which needs to maintain running in a
system. The value of W atchdog Timer must be set bigger than
the running time of program A. Then, after the running time of
program A is finished, either to disable or to reset watchdog
timer.
W hen program A has problems to make system shut down, the
system can be rebooted by W atchdog timer when the value of
watchdog timer is countdowned to 0 .
The below flowchart can be referred to edit program A