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6174B–ATARM–07-Nov-05
AT91FR40162S Preliminary
• Software Trigger: Each channel has a software trigger, available by setting SWTRG in
TC_CCR.
• 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 TC_BCR (Block Control) with SYNC set.
• Compare RC Trigger: RC is implemented in each channel and can provide a trigger when the
counter value matches the RC value if CPCTRG is set in TC_CMR.
The Timer Counter channel can also be configured to have an external trigger. In Capture Mode,
the external trigger signal can be selected between TIOA and TIOB. In Waveform Mode, an
external event can be programmed on one of the following signals: TIOB, XC0, XC1 or XC2.
This external event can then be programmed to perform a trigger by setting ENETRG in
TC_CMR.
If an external trigger is used, the duration of the pulses must be longer than the system clock
(MCK) period in order to be detected.
Whatever the trigger used, it will be taken into account at the following active edge of the
selected clock. This means that the counter value may not read zero just after a trigger, espe-
cially when a low frequency signal is selected as the clock.