Watchdog

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Depends on Real TimeReset

A watchdog timer is a feature of many high-reliability real-time systems. It takes the place of the (depressingly familiar) “try switching it off and on again” approach in far too many interactive, computerised goods.

A watchdog relies on an automated fail-safe process; it only comes into effect when something doesn’t happen. A successfully running system is expected to tell some supervisory layer – and eventually the real-time operating system – that it is still okay. If it fails to do this within a certain time it is assumed to have gone wrong and the hardware forces a reset.

Here’s a little anecdote.