AXIOMTEK PICO300, User Manual, Page: 90 / 96

PICO300 Pico-ITX Board
84 Watchdog Timer
B.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