21.3.3.1.2 Time-Out Check Mode

In the Time-Out Check mode, the peripheral starts counting on the first signal edge and stops on the next signal edge detected on the event input channel. Start or Stop edge is determined by the Event Edge (EDGE) bit in the Event Control (TCBn.EVCTRL) register. If the Count (TCBn.CNT) register reaches TOP before the second edge, a CAPT interrupt and event will be generated. In Freeze state, after a Stop edge is detected, the counter will restart on a new Start edge. If TOP is updated to a value lower than the Count (TCBn.CNT) register upon reaching MAX the counter restarts from BOTTOM. Reading the Count (TCBn.CNT) register or Compare/Capture (TCBn.CCMP) register, or writing the Run (RUN) bit in the Status (TCBn.STATUS) register in Freeze state will have no effect.

This mode requires TCB to be configured as an event user and is explained in the Events section.
Figure 21-4. Time-Out Check Mode