25.3.3.4 Noise Canceler

The Noise Canceler improves noise immunity by using a simple digital filter scheme. When the Noise Filter (FILTERA) bit in the Event Control (TCFn.EVCTRL) register is enabled, the peripheral monitors the event channel and keeps the last four observed samples. If four consecutive samples are equal, the input is considered stable, and the signal is fed to the edge detector.

When enabled, the Noise Canceler introduces an additional delay of five clock cycles between a change applied to the input and the event action.

The Noise Canceler uses the Timer/Counter clock and is not affected by the prescaler.