19.6.3 WDT Operation in Idle Mode
The WDT, if enabled, continues operation in the Idle mode. The WDT may be used to wake the device from the Idle mode. When the WDT times out in Idle, an NMI is generated and the WDTO bit (RCON[4]) is set. The NMI vectors execution to the CPU start-up address but does not Reset registers or peripherals. The IDLE status bit (RCON[2]) is set, indicating the device was in the Idle mode. These bits allow the start-up code to determine the cause of the wake-up.