Lanner NCA-5520, Руководство пользователя

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Appendix B: Programming Watchdog Timer
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APPENDIX B: 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
resumed 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.
To execute the sample code: enter the number of seconds to start countdown 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)
Watchdog Timer
Processor
Reset
Restart
Clock