User`s manual

CAPA831 Intel
®
Atom
TM
D2550/N2800/N2600 Processor 3.5” SBC
66 Watchdog Timer
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,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
mov al,Nh ;N=00h or 08h(see below Note )
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 below Note )
;Disable WDT:
mov dx,2Eh
mov al,30h
out dx,al
mov dx,2Fh
mov al,00h ;Can be disabled at any time
out dx,al
Note:
If N=00h, 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