20.4.2.2 Window Mode

In Window mode operation, the WDT uses two different time specifications: The WDT can only be cleared by writing 0xA5 to the CLEAR register after the closed window time-out period (TO_WDTW), during the subsequent Normal time-out period (TO_WDT). If the WDT is cleared before the time window opens (before TO_WDTW is over), the WDT will issue a system Reset request.

The TO_WDTW and TO_WDT parameters are periods that range from 8 ms to 16s. The total duration of the WDT time-out period is the sum of the two parameters.

The closed window period is defined by the Window Mode Time-Out Period bit field in the Configuration register (CONFIG.WINDOW), and the open window period is defined by the Time-Out Period bit field in the Configuration register (CONFIG.PER).