AT32UC3C1512C Automotive Atmel Corporation, AT32UC3C1512C Automotive Datasheet - Page 832

• Manufacturer Part Number: AT32UC3C1512C Automotive
• Manufacturer: Atmel Corporation

31.6.1.6
31.6.1.7
31.6.2
31.6.2.1
9166C–AVR-08/11
Capture Operating Mode
Trigger
Peripheral events on TIOA/TIOB inputs
Capture registers A and B
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.
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:
The 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 to be one of the following signals: TIOB, XC0, XC1, or XC2. This external
event can then be programmed to perform a trigger by writing a one to the External Event Trig-
ger Enable bit in CMRn (CMRn.ENETRG).
If an external trigger is used, the duration of the pulses must be longer than the CLK_TC period
in order to be detected.
Regardless of the trigger used, it will be taken into account at the following active edge of the
selected clock. This means that the counter value can be read differently from zero just after a
trigger, especially when a low frequency signal is selected as the clock.
The TIOA/TIOB input lines are ored internally with peripheral events from the Peripheral Event
System. To capture using events the user must ensure that the corresponding pin functions for
the TIOA/TIOB line are disabled. When capturing on the external TIOA/TIOB pin the user must
ensure that no peripheral events are generated on this pin.
This mode is entered by writing a zero to the CMRn.WAVE bit.
Capture mode allows the TC channel to perform measurements such as pulse timing, fre-
quency, period, duty cycle and phase on TIOA and TIOB signals which are considered as
inputs.
Figure 31-4 on page 834
ture mode.
Registers A and B (RA and RB) are used as capture registers. This means that they can be
loaded with the counter value when a programmable event occurs on the signal TIOA.
• Software Trigger: each channel has a software trigger, available by writing a one to the
• SYNC: each channel has a synchronization signal SYNC. When asserted, this signal has the
• Compare RC Trigger: RC is implemented in each channel and can provide a trigger when the
Software Trigger Command bit in CCRn (CCRn.SWTRG).
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).
counter value matches the RC value if the RC Compare Trigger Enable bit in CMRn
(CMRn.CPCTRG) is written to one.
shows the configuration of the TC channel when programmed in Cap-
AT32UC3C
832