Programming the watchdog timer – Adaptec SBC-599 User Manual
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SBC-596/599 User's Manual
Programming the Watchdog Timer
In order to program the watchdog timer, you must write a program
which writes I/O port address 443 (hex). The output data is a
value of time interval. The value range is from 01(hex) to 3F(hex),
and the related time interval is 1 sec. to 63 sec.
Data
Time Interval
01
1 sec.
02
2 sec.
03
3 sec.
04
4 sec.
.
.
.
3F
63 sec.
After data entry, your program must refresh the watchdog timer
by rewriting the I/O port 443 (hex) while simultaneously setting
it. When you want to disable the watchdog timer, your program
should read I/O port 043 (hex).
The following example shows how you might program the
watchdog timer in BASIC:
10
REM Watchdog timer example program
20
OUT &H443, data REM Start and restart the
watchdog
30
GOSUB 1000 REM Your application task #1
40
OUT &H443, data REM Reset the timer
50
GOSUB 2000 REM Your application task #2
60
OUT &H443, data REM Reset the timer
70
X=INP (&H043) REM Disable the watchdog
timer
80
END
1000
REM Subroutine #1, you application task
.
.
.
1070
RETURN
2000
REM Subroutine #2, you application task
.
.
.
2090
RETURN