Teknor Industrial Computers VIPer 821 Technical Reference Manual page 42

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The Watchdog is provided to monitor the processor's inactivity. It issues a failure signal if
the processor fails to refresh the watchdog within a timeout period (1.6 seconds).
SETUPS
Related Jumpers
The watchdog can be enabled/disabled onboard using the W8 jumper.
BIOS Level
No setting required.
OPERATION
When operating with the watchdog, be aware of the following:
1. The watchdog timer must be enabled by setting High (Enable) the Watchdog status bit
(Bit 0 – Supervisor Register x90h).
2. The watchdog timer must be refreshed (reset) by software. This operation is controlled
by Bit 1 – Supervisor Register x90h that must be toggled from 0 to 1 every 1.6 seconds.
3. If a failure occurs, the watchdog generates a system reset.
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