Datasheet

When a pause is detected, the counter can stop immediatly maintaining its current value and all
waveforms keep their current state, as long as a start event action is detected: Input Event Action 0 bits in
Event Control register (EVCTRL.EVACT0=0x3, START).
Re-Trigger Command and Event Action
A re-trigger command can be issued from software by using TCC Command bits in Control B Set register
(CTRLBSET.CMD=0x1, RETRIGGER), or from event when the re-trigger event action is configured in the
Input Event 0/1 Action bits in Event Control register (EVCTRL.EVACTn=0x1, RETRIGGER).
When the command is detected during counting operation, the counter will be reloaded or cleared,
depending on the counting direction (CTRLBSET.DIR or CTRLBCLR.DIR). The Re-Trigger bit in the
Interrupt Flag Status and Clear register will be set (INTFLAG.TRG). It is also possible to generate an
event by writing a '1' to the Re-Trigger Event Output Enable bit in the Event Control register
(EVCTRL.TRGEO). If the re-trigger command is detected when the counter is stopped, the counter will
resume counting operation from the value in COUNT.
Note:
When a re-trigger event action is configured in the Event Action bits in the Event Control register
(EVCTRL.EVACTn=0x1, RETRIGGER), enabling the counter will not start the counter. The counter will
start on the next incoming event and restart on corresponding following event.
Start Event Action
The start action can be selected in the Event Control register (EVCTRL.EVACT0=0x3, START) and can
start the counting operation when previously stopped. The event has no effect if the counter is already
counting. When the module is enabled, the counter operation starts when the event is received or when a
re-trigger software command is applied.
Note:
When a start event action is configured in the Event Action bits in the Event Control register
(EVCTRL.EVACT0=0x3, START), enabling the counter will not start the counter. The counter will start on
the next incoming event, but it will not restart on subsequent events.
Count Event Action
The TCC can count events. When an event is received, the counter increases or decreases the value,
depending on direction settings (CTRLBSET.DIR or CTRLBCLR.DIR).
The count event action is selected by the Event Action 0 bit group in the Event Control register
(EVCTRL.EVACT0=0x5, COUNT).
Direction Event Action
The direction event action can be selected in the Event Control register (EVCTRL.EVACT1=0x2, DIR).
When this event is used, the asynchronous event path specified in the event system must be configured
or selected. The direction event action can be used to control the direction of the counter operation,
depending on external events level. When received, the event level overrides the Direction settings
(CTRLBSET.DIR or CTRLBCLR.DIR) and the direction bit value is updated accordingly.
Increment Event Action
The increment event action can be selected in the Event Control register (EVCTRL.EVACT0=0x4, INC)
and can change the counter state when an event is received. When the TCE0 event (TCCx_EV0) is
received, the counter increments, whatever the direction setting (CTRLBSET.DIR or CTRLBCLR.DIR) is.
Decrement Event Action
SAM D21 Family
TCC – Timer/Counter for Control Applications
© 2018 Microchip Technology Inc.
Datasheet Complete
DS40001882D-page 712