Watchdog Timer - BOSER Technology HS-4610 Manual

3.18 Watchdog Timer

Once the Enable cycle is active a Refresh cycle is requested before the
time-out period. This restarts counting of the WDT period. When the
time counting goes over the period preset of WDT, it will assume that
the program operation is abnormal. A reset system signal will restart
when such error happens.
The following sample programs show how to enable, disable and
refresh the watchdog timer:
.286
.MODEL SMALL
.DATA
x1 db '------------------------------------------------------',0ah,0dh,'$'
copyright db '|Copyright by Boser technology write by Richard |',0ah,0dh,'$'
x2 db '------------------------------------------------------',0ah,0dh,'$'
port equ
datao equ
.CODE
print macro
mov
mov
int
endm
begin proc
mov
mov
STI
mov
mov
out
jmp
out
mov
mov
out
jmp
mov
mov
out
jmp
mov
mov
out
jmp
mov
mov
out
18
;this is data area
04Eh ;W83697H Chipset port
04Fh ;data port
buff
dx,offset buff;
ah,09h
21h
near
ax,@data
ds,ax
; W83697H
dx,port ; Unlock registor
al,087H ;
dx,al
$+2
dx,al
dx,port ;
al,07H ;
dx,al
$+2
dx,datao ; set device 8
al,08H ;
dx,al
$+2
dx,port ; Watchdog IO function
al,030H ; registor
dx,al
$+2
dx,datao ; set 01h toactivate
al,01H ;
dx,al