Window Mode

In Window mode operation, the WDT uses two different time-out periods: A closed window time-out period (TOWDTW) and an open window time-out period (TOWDT):

When enabling the Window mode or going out of the Debug mode, the window is activated after the first WDR instruction.

The figure below shows a typical timing scheme for the WDT operating in Window mode.

Figure 1. Window Mode Operation

The Window mode is enabled by writing a non-zero value to the WINDOW bit field in the Control A (WDT.CTRLA) register and disabled by writing it to 0x0.