DFI-ITOX 586ITOX, User Manual

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E
Watchdog Timer
83
Using the Watchdog Timer Function
The following are the parameters for enabling or disabling the
Watchdog Timer function when using the GWBASIC or
ASSEMBLY applications.
When enabled, the application accesses read port 443 (HEX).
When disabled, it accesses read port 43 (HEX).
GWBASIC
To enable Watchdog Timer and reload the timer, type:
A = INP (&H443)
To disable, type:
A = INP (&H43)
ASSEMBLY
To enable Watchdog Timer and reload the timer, type:
MOV DX, 0443H
IN AL, DX
To disable, type:
MOV DX, 043H
IN AL, DX
Please note that your custom software must regularly reload the
timer (by reading that por t) before the Watchdog Timer times
out. Otherwise, the system will think the machine has already
hung-up and will next reboot. Remember to disable it before the
software ends/exits.