The watchdog timer is used to reset the processor, when the software gets blocked.
Once enabled, the 32bit watchdog timer register gets decremented every clock cycle. If the Toggle Watchdog C-Node is executed, the watchdog timer register is reloaded with the value given by the Enable Watchdog C-Node.
If the watchdog timer register reaches zero before it is toggled or stopped the processor is reseted and the flashed program is booted and executed from start.