15.3.2.5 Synchronization
Events can be either synchronous or asynchronous to the peripheral clock. Each Event System channel has two subchannels: one asynchronous and one synchronous.
The asynchronous subchannel is identical to the event output from the generator. If the event generator generates a signal asynchronous to the peripheral clock, the signal on the asynchronous subchannel will be asynchronous. If the event generator generates a signal synchronous to the peripheral clock, the signal on the asynchronous subchannel will also be synchronous.
The synchronous subchannel is identical to the event output from the generator, if the event generator generates a signal synchronous to the peripheral clock. If the event generator generates a signal asynchronous to the peripheral clock, this signal is first synchronized before being routed onto the synchronous subchannel. Depending on when it occurs, synchronization will delay the event by two to three clock cycles. The Event System automatically performs this synchronization if an asynchronous generator is selected for an event channel.