SBC82621 Socket370 Half-size All-in-One CPU Card User’s Manual
A p p e n d i x A
Watchdog Timer
Using the Watchdog Function
The
SBC82621
CPU card uses version 2.0 of the watchdog
timer. This onboard WDT generates either a system reset or
non-maskable interrupt (NMI), depending on the settings made
on jumper
JP3
of
SBC82621
. Follow the steps below to enable
and program the watchdog function of
SBC82621
.
Start
↓
Un-Lock WDT
:
OUT 120H 0AH ; enter WDT function
OUT 120H 0BH ; enable WDT function
↓
Set multiple (1~4)
:
OUT 120 0NH ; N=1,2,3 or 4
↓
Set base timer (0~F) :
OUT 121 0MH ; M=0,1,2,…F
↓
WDT counting
↓
re-set timer
:
OUT 121 0MH ; M=0,1,2,…F
↓
IF No re-set timer
:
WDT time-out, generate RESET or NMI
↓
IF to disable WDT
:
OUT 120 00H ; Can be disable at any time
Watchdog Timer
59
