9.5 Windowed Watchdog Timer (WWDT) Reset
The Windowed Watchdog Timer generates a Reset if the firmware does
         not issue a CLRWDT instruction within the time-out
         period or window set. The TO and
            PD bits in the STATUS register and the
            RWDT bit are changed
         to indicate a WDT Reset. The WDTWV bit indicates if the
         WDT Reset has occurred due to a time-out or a window violation.
