Appendix A: Programming Watchdog Timer - Lanner FW-8877 User Manual

Appendix A
Programming Watchdog Timer
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 watchdog folder on the
Driver and Manual CD
To execute the sample code: enter the number of seconds
to start count down before the system can be reset. Press
start to start the counter and stop to stop the counter..
Dwd_tst --swt xxx (Set Watchdog Timer 1-255 seconds)
wd_tst[*] --start (Start Watchdog Timer)
wd_tst --stop (Stop Watchdog Timer)
For sample watchdog code, see watchdog folder on the
Driver and Manual CD
31
Network Application Platforms