22.3.4 Events
| Generator Name | Description | Event Type | Generating Clock Domain | Length of Event | |
|---|---|---|---|---|---|
| Peripheral | Event | ||||
| TCBn | CAPT | CAPT flag set | Pulse | CLK_PER | One CLK_PER period |
| OVF | OVF flag set | ||||
The conditions for generating the CAPT and OVF events are identical to those that will raise the corresponding interrupt flags in the Timer/Counter Interrupt Flags (TCBn.INTFLAGS) register. Refer to the EVSYS - Event System section for more details regarding event users and configuration.
| User Name | Description | Input Detection | Async/Sync | |
|---|---|---|---|---|
| Peripheral | Input | |||
| TCBn | CAPT | Time-Out Check Count mode | Edge | Sync |
| Input Capture on Event Count mode | ||||
| Input Capture Frequency Measurement Count mode | ||||
| Input Capture Pulse-Width Measurement Count mode | ||||
| Input Capture Frequency and Pulse-Width Measurement Count mode | ||||
| Single-Shot Count mode | Both | |||
| COUNT | Event as clock source in combination with a count mode | Sync | ||
CAPT and COUNT are TCB event users that detect and act upon input events.
The COUNT event user is enabled on the peripheral by modifying the Clock Select (CLKSEL) bit field in the Control A (TCBn.CTRLA) register to EVENT and setting up the Event System accordingly.
If the Capture Event Input Enable (CAPTEI) bit in the Event Control (TCBn.EVCTRL) register
is written to ‘1’, incoming events will result in an event action as
defined by the Event Edge (EDGE) bit in Event Control (TCBn.EVCTRL) register, and the Timer
Mode (CNTMODE) bit field in Control B (TCBn.CTRLB) register. The event must last for at
least one CLK_PER cycle to be recognized.
If the Asynchronous mode is enabled for Single-Shot mode, the event is edge-triggered and will capture changes on the event input shorter than one peripheral clock cycle.