37
043
(hex)
Read
Disable the Watch-Dog Timer.
To enable the Watch-Dog Timer, a read from I/O port 443H
must be performed. This will enable and activate the countdown
timer which will eventually time out and either reset the CPU or
cause an NMI depending on the setting of JP9. To ensure that
this reset condition does not occur, the Watch-Dog Timer must
be periodically refreshed by reading the same I/O port 433H.
This must be done within the time out period that is selected by
jumper group JP11.
A tolerance of at least 30% must be maintained to avoid
unknown routines within the operating system (DOS), such as
disk I/O that can be very time consuming. Therefore if the time
out period has been set to 10 seconds, the I/O port 443H must
be read within 7 seconds.
Note: when exiting a program it is necessary to disable the Watch-
Dog Timer, otherwise the system will reset.
Summary of Contents for ROCKY-P218BXA Pentium II & Creative Sound
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