40.6.3.3 Minimum Capture
The minimum capture is enabled by writing the CAPTMIN mode in the Channel n Capture Mode bits in the Control A register (CTRLA.CAPTMODEn = CAPTMIN).
CCx Content:
In CAPTMIN operations, CCx keeps the minimum captured values. Before enabling this mode of capture, the user must initialize the corresponding CCx register value to a value different from zero. If the CCx register initial value is zero, no capture is performed using the corresponding channel.
MCx Behaviour:
In the CAPTMIN operation, the capture is performed only if, when on capture event time, the counter value is lower than the last captured value. The MCx interrupt flag is set only if, when on capture event time, the counter value is higher or equal to the value captured on the previous event. So the interrupt flag is set when a new absolute local minimum value is detected.