The corresponding capture is done only if the channel is enabled in capture mode (CTRLA.CPTENx=1). If
not, the capture action will be ignored and the channel will be enabled in compare mode of operation.
When only one of these channel is required, the other channel can be used for other purposes.
The TCC can detect capture overflow of the input capture channels: When a new capture event is
detected while the INTFLAG.MCx is still set, the new timestamp will not be stored and INTFLAG.ERR will
be set.
Note:
When up-counting (CTRLBSET.DIR=0), counter values lower than 1 cannot be captured in
Capture Minimum mode (FCTRLn.CAPTURE=CAPTMIN). To capture the full range including value 0, the
TCC must be configured in down-counting mode (CTRLBSET.DIR=0).
Note:
In dual-slope PWM operation, and when TOP is lower than MAX/2, the CCx MSB captures the
CTRLB.DIR state to identify the ramp on which the capture has been done. For rising ramps CCx[MSB] is
zero, for falling ramps CCx[MSB]=1.
36.6.3. Additional Features
36.6.3.1. One-Shot Operation
When one-shot is enabled, the counter automatically stops on the next counter overflow or underflow
condition. When the counter is stopped, the Stop bit in the Status register (STATUS.STOP) is set and the
waveform outputs are set to the value defined by DRVCTRL.NREx and DRVCTRL.NRVx.
One-shot operation can be enabled by writing a '1' to the One-Shot bit in the Control B Set register
(CTRLBSET.ONESHOT) and disabled by writing a '1' to CTRLBCLR.ONESHOT. When enabled, the TCC
will count until an overflow or underflow occurs and stop counting. The one-shot operation can be
restarted by a re-trigger software command, a re-trigger event or a start event. When the counter restarts
its operation, STATUS.STOP is automatically cleared.
36.6.3.2. Circular Buffer
The Period register (PER) and the compare channels register (CC0 to CC3) support circular buffer
operation. When circular buffer operation is enabled, the PER or CCx values are copied into the
corresponding buffer registers at each update condition. Circular buffering is dedicated to RAMP2,
RAMP2A, and DSBOTH operations.
Figure 36-17. Circular Buffer on Channel 0
BUFV
UPDATE
"write enable"
"data write"
=
COUNT
"ma tch"
EN
EN
CCBUF0
CC0
UPDATE
CIRCC0EN
36.6.3.3. Dithering Operation
The TCC supports dithering on Pulse-width or Period on a 16, 32 or 64 PWM cycles frame.
Atmel SAM L22G / L22J / L22N [DATASHEET]
Atmel-42402E-SAM L22G / L22J / L22N_Datasheet_Complete-07/2016
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