AXIOMTEK NANO820, User Manual

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NANO840/842 Nano-ITX Board
58 Watchdog Timer
A.3 Sample Program
Assembly sample code :
;Enable WDT:
mov
dx,2Eh
mov al,87 ;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,07h
out dx,al
;Enable WDT base address:
mov
dx,2Eh
mov al,30h
out dx,al
mov dx,2Fh
mov al,01h
out dx,al
;Activate WDT:
mov
dx,2Eh
mov al,0F0h
out dx,al
mov dx,2Fh
mov al,80h
out dx,al
;Set base timer :
mov
dx,2Eh
mov al,0F6h
out dx,al
mov dx,2Fh
mov al,Mh ;M=00h,01h,...FFh (hex),Value=0 to 255
out dx,al ;(see Note below)
;Set Second or Minute :
mov
dx,2Eh
mov al,0F5h
out dx,al
mov dx,2Fh
mov al,Nh ;N=71h or 79h(see
Note
below)
out dx,al
Note:
If
N =71h, the time base is set to second.
M = time value
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
.
.
FFh: Time-out occurs after 255 seconds