Reset the system if software stops responding.
A watchdog timer resets the MCU unless software kicks it periodically, recovering from hangs. Window watchdogs also catch too-fast kicking. Kick only from a healthy supervisory task, not an ISR. Independent oscillator makes it robust.
If the main loop deadlocks, the watchdog reboots the device.
Watchdog timers reset a stuck system automatically, which is an important safety feature in remote and safety-related products.
Reset the system if software stops responding.
Watchdog timers reset a stuck system automatically, which is an important safety feature in remote and safety-related products.
Software must regularly refresh the timer, and if it stops refreshing, the timer expires and resets the processor.
A watchdog that must be refreshed only within a set time window, which catches software that runs too fast as well as software that stops.
Typical applications include resetting a remote sensor that freezes after an unexpected input, protecting a motor controller from software lock-up and recovering a medical device from a fault without a user needing to intervene.
Study "Power management" first (topic 74 of 104 in Electronics & Embedded). It covers the groundwork this topic builds on.
Timeout selection. Reset reason register. Safety standards require it.
If the main loop deadlocks, the watchdog reboots the device.
The next topic is "Debugging tools", which builds directly on this one.
It is classed as Advanced in Electronics & Embedded (topic 75 of 104). It is an advanced topic. It assumes you are comfortable with the intermediate topics in Electronics & Embedded.
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