SAM7S16_14 Datasheet, PDF (462/775 Pages) ATMEL Corporation – Internal High-speed Flash

33.5.12 External Event/Trigger Conditions
An external event can be programmed to be detected on one of the clock sources (XC0, XC1, XC2) or TIOB. The
external event selected can then be used as a trigger.
The EEVT parameter in TC_CMR selects the external trigger. The EEVTEDG parameter defines the trigger edge
for each of the possible external triggers (rising, falling or both). If EEVTEDG is cleared (none), no external event is
defined.
If TIOB is defined as an external event signal (EEVT = 0), TIOB is no longer used as an output and the compare
register B is not used to generate waveforms and subsequently no IRQs. In this case the TC channel can only gen-
erate a waveform on TIOA.
When an external event is defined, it can be used as a trigger by setting bit ENETRG in TC_CMR.
As in Capture Mode, the SYNC signal and the software trigger are also available as triggers. RC Compare can also
be used as a trigger depending on the parameter WAVSEL.
33.5.13 Output Controller
The output controller defines the output level changes on TIOA and TIOB following an event. TIOB control is used
only if TIOB is defined as output (not as an external event).
The following events control TIOA and TIOB: software trigger, external event and RC compare. RA compare con-
trols TIOA and RB compare controls TIOB. Each of these events can be programmed to set, clear or toggle the
output as defined in the corresponding parameter in TC_CMR.
SAM7S Series [DATASHEET]
6175M–ATARM–26-Oct-12
462