27.2.3 Early Warning
In some cases it is desirable to receive an early warning that the Watchdog is about to expire, so that some system action (such as saving any system configuration data for failure analysis purposes) can be performed before the system reset occurs. The Early Warning feature of the Watchdog module allows such a notification to be requested; after the configured early warning time (but before the expiry of the Watchdog counter) the Early Warning flag will become set, so that the user application can take an appropriate action.
Note: It is important to note that the purpose of the Early Warning feature is not to allow the user application to reset the Watchdog; doing so will defeat the safety the module gives to the user application. Instead, this feature should be used purely to perform any tasks that need to be undertaken before the system reset occurs.