35.6.3.4 Maximum Capture (SAM C20/C21 N only)

The maximum capture is enabled by writing the CAPTMAX mode in the Channel n Capture Mode bits in the Control A register (CTRLA.CAPTMODEn = CAPTMAX).

CCx Content:

In CAPTMAX operations, CCx keeps the Maximum captured values. Before enabling this mode of capture, the user must initialize the corresponding CCx register value to a value different from TOP. If the CCx register initial value is TOP, no captures will be performed using the corresponding channel.

MCx Behaviour:

In CAPTMAX operation, capture is performed only when on capture event time, the counter value is upper than the last captured value. The MCx interrupt flag is set only when on capture event time, the counter value is lower or equal to the value captured on the previous event. So interrupt flag is set when a new absolute local Maximum value has been detected.