Appendix A: Programming Watchdog Timer - Lanner NCA-5210 User Manual

APPENDIX A: PROGRAMMING WATCHDOG TIMER

A watchdog timer is a piece of hardware that can be used to automatically detect system anomalies and
reset the processor in case there are any problems. Generally speaking, a watchdog timer is based on a
counter that counts down from an initial value to zero. The software selects the counter's initial value and
periodically restarts it. Should the counter reach zero before the software restarts it, the software is presumed
to be malfunctioning
and the processor's reset signal is asserted. Thus, the processor will be restarted as if a human operator had
cycled the power.
For sample watchdog code, see WD folder under Driver and Utility on the Driver and Manual CD.
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