Each TCC instance has up to four compare/capture channels (CCx).
The counter register (COUNT), period registers with buffer (PER and PERBUF), and compare and
capture registers with buffers (CCx and CCBUFx) are 16- or 24-bit registers, depending on each TCC
instance. Each buffer register has a buffer valid (BUFV) flag that indicates when the buffer contains a new
value.
Under normal operation, the counter value is continuously compared to the TOP or ZERO value to
determine whether the counter has reached TOP or ZERO. In either case, the TCC can generate
interrupt requests or generate events for the Event System. In waveform generator mode, these
comparisons are used to set the waveform period or pulse width.
A prescaled generic clock (GCLK_TCCx) and events from the event system can be used to control the
counter. The event system is also used as a source to the input capture.
The Recoverable Fault Unit enables event controlled waveforms by acting directly on the generated
waveforms of the TCC compare channels output. These events can restart, halt the timer/counter period,
shorten the output pulse active time, or disable waveform output as long as the fault condition is present.
This can typically be used for current sensing regulation, and zero-crossing and demagnetization re-
triggering.
The MCE0 and MCE1 event sources are shared with the Recoverable Fault Unit. Only asynchronous
events are used internally when fault unit extension is enabled. For further details on how to configure
asynchronous events routing, refer to
EVSYS – Event System
.
Recoverable fault sources can be filtered and/or windowed to avoid false triggering, for example from I/O
pin glitches, by using digital filtering, input blanking, and qualification options. See also
.
In addition, six optional independent and successive units primarily intended for use with different types of
motor control, ballast, LED, H-bridge, power converter, and other types of power switching applications,
are implemented in some of TCC instances. See also
The output matrix (OTMX) can distribute and route out the TCC waveform outputs across the port pins in
different configurations, each optimized for different application types. The Dead-Time Insertion (DTI) unit
splits the four lower OTMX outputs into two non-overlapping signals: the non-inverted low side (LS) and
inverted high side (HS) of the waveform output with optional dead-time insertion between LS and HS
switching. The SWAP unit can swap the LS and HS pin outputs, and can be used for fast decay motor
control.
The pattern generation unit can be used to generate synchronized waveforms with constant logic level on
TCC UPDATE conditions. This is useful for easy stepper motor and full bridge control.
The non-recoverable fault module enables event controlled fault protection by acting directly on the
generated waveforms of the timer/counter compare channel outputs. When a non-recoverable fault
condition is detected, the output waveforms are forced to a safe and pre-configured value that is safe for
the application. This is typically used for instant and predictable shut down and disabling high current or
voltage drives.
The count event sources (TCE0 and TCE1) are shared with the non-recoverable fault extension. The
events can be optionally filtered. If the filter options are not used, the non-recoverable faults provide an
immediate asynchronous action on waveform output, even for cases where the clock is not present. For
further details on how to configure asynchronous events routing, refer to section
EVSYS – Event System
.
Related Links
Atmel SAM L22G / L22J / L22N [DATASHEET]
Atmel-42402E-SAM L22G / L22J / L22N_Datasheet_Complete-07/2016
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