SAM4L Datasheet, PDF (801/1185 Pages) ATMEL Corporation – ATSAM ARM-based Flash MCU

Figure 30-2. Clock Control
Selected
Clock
Trigger
ATSAM4L4/L2
Q
S
R
CLKSTA CLKEN CLKDIS
Q
S
R
Counter
Clock
Stop Disable
Event Event
30.6.1.5
30.6.1.6
TC operating modes
Each channel can independently operate in two different modes:
• Capture mode provides measurement on signals.
• Waveform mode provides wave generation.
The TC operating mode selection is done by writing to the Wave bit in the CCRn register
(CCRn.WAVE).
In Capture mode, TIOA and TIOB are configured as inputs.
In Waveform mode, TIOA is always configured to be an output and TIOB is an output if it is not
selected to be the external trigger.
Trigger
A trigger resets the counter and starts the counter clock. Three types of triggers are common to
both modes, and a fourth external trigger is available to each mode.
The following triggers are common to both modes:
• Software Trigger: each channel has a software trigger, available by writing a one to the
Software Trigger Command bit in CCRn (CCRn.SWTRG).
• SYNC: each channel has a synchronization signal SYNC. When asserted, this signal has the
same effect as a software trigger. The SYNC signals of all channels are asserted
simultaneously by writing a one to the Synchro Command bit in the BCR register
(BCR.SYNC).
• Compare RC Trigger: RC is implemented in each channel and can provide a trigger when the
counter value matches the RC value if the RC Compare Trigger Enable bit in CMRn
(CMRn.CPCTRG) is written to one.
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