Event Users

The event channel to listen to is selected by configuring the event user. An event user may require the event signal to be either synchronous or asynchronous to the peripheral clock. An asynchronous event user can respond to events in Sleep modes when clocks are not running. Such events can be responded to outside the normal edges of the peripheral clock, making the event user respond faster than the clock frequency would suggest. For details on the requirements of each peripheral, refer to the documentation of the corresponding peripheral.

Most event users implement edge or level detection to trigger actions in the corresponding peripheral based on the incoming event signal. In both cases, a user can either be synchronous, which requires that the incoming event is generated from the peripheral clock (CLK_PER), or asynchronous, if not. Some asynchronous event users do not apply event input detection but use the event signal directly.

The different event user properties are described in the table below.

Table 1. Properties of Event Users
Input Detection	Async/Sync	Description
Edge	Sync	An event user is triggered by an event edge and requires that the incoming event is generated from CLK_PER
Edge	Async	An event user is triggered by an event edge and has asynchronous detection or an internal synchronizer
Level	Sync	An event user is triggered by an event level and requires that the incoming event is generated from CLK_PER
Level	Async	An event user is triggered by an event level and has asynchronous detection or an internal synchronizer
No detection	Async	An event user will use the event signal directly

The table below shows the available event users for this device family.

Table 2. Event Users
User	Module/Event Mode	Input Format	Asynchronous
TCAn	CNT_POSEDGE	Edge	No
	CNT_ANYEDGE	Edge	No
	CNT_HIGHLVL	Level	No
	UPDOWN	Level	No
TCBn	Time-out check	Edge	No
	Input Capture on Event	Edge	No
	Input Capture Frequency Measurement	Edge	No
	Input Capture Pulse-Width Measurement	Edge	No
	Input Capture Frequency and Pulse Width Measurement	Edge	No
	Single-Shot	Edge	Yes
USARTn	IrDA Mode	Level	No
CCLLUTnx	LUTn input x or clock signal	Level	Yes
ADCn	ADC start on event	Edge	Yes
EVOUTx	Forward event signal to pin	Level	Yes