28.5.2.4 Event System Channel
An event channel can select one event from a list of event generators. Depending on configuration, the selected event could be synchronized, resynchronized or asynchronously sent to users. When synchronization or resynchronization is required, the channel includes an internal edge detector, allowing the Event System to generate internal events when rising, falling or both edges are detected on the selected event generator. After the event channel is configured and enabled, the Channel Busy bit (CHSTATUS.CHBUSYn) will not be set for one generic clock (GCLK_EVSYS_CHANNELn) cycle. Before the first event is exercised, the application must wait one clock cycle for the channel to finalize the configuration when synchronous channels are used.
An event channel is able to generate internal events for specific software commands, see channel Block Diagram.