AXIOMTEK SBC84833 Series, User Manual

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SBC84833 Series All-In-One Capa Board User’s Manual
Watchdog Timer
69
APPENDIX A
WATCHDOG TIMER
What is Watchdog Timer
The integrated Watchdog Timer can be set up by programming.
There are 1~255 levels available. As long as the vaule of timer
is set, after enabling, the countdown of the value is starting. It
needs to reset or disable watchdog, otherwise auto-reset will be
running when the value is counted to 0.
How to Use the Watchdog Timer
z Assembler Sample Code
;Enable WDT:
Mov dx,2Eh
Mov
al,87h ;Un-lock super I/O
out dx,al
out dx,al
;Select Logic device:
mov dx,2Eh
mov
al,07h
out dx,al
mov dx,2Fh
mov
al,08h
out dx,al
;Activate WDT:
mov
dx,2Eh
Mov al,30h
out dx,al
mov dx,2Fh
mov al,01h
out dx,al
;Set Second or Minute :
Mov
dx,2Eh
Mov al,0F5h
out dx,al
mov dx,2Fh