Normal Mode

In Normal mode operation, a single time-out period is set for the WDT. If the WDT is not reset from software using the WDR any time before the time-out occurs, the WDT will issue a system Reset.

A new WDT time-out period will be started each time the WDT is reset by WDR.

There are 11 possible WDT time-out periods (TOWDT), selectable from 8 ms to 8s by writing to the Period (PERIOD) bit field in the Control A (WDT.CTRLA) register.

Figure 1. Normal Mode Operation

Normal mode is enabled as long as the WINDOW bit field in the Control A (WDT.CTRLA) register is 0x0.