AXIOMTEK EP100, User Manual

Page: 62 / 68

EP100 AMD Embedded G-Series Processor EPIC Board with LVDS
56 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