Alternate RAMP2 (RAMP2A) Operation
Alternate RAMP2 operation is similar to RAMP2, but CC0 controls both WO[0] and WO[1] waveforms
when the corresponding circular buffer option is enabled (CIPEREN=1). The waveform polarity is the
same on both outputs. Channel 1 can be used in capture mode.
Figure 36-19. RAMP2 Alternate Operation
COUNT
"match"
ZERO
"clear" update
A
B
A
B
Ramp
WO[0]
WO[1]
TOP(A)
TOP(B)
CC0(A)
CC0(B)
TOP(B)
CC0(A)
CC0(B)
Retrigger
on
FaultA
CIPEREN = 1
POL0 = 1
CICCEN0 = 1
FaultA input
Keep on FaultB
FaultB input
36.6.3.5. Recoverable Faults
Recoverable faults can restart or halt the timer/counter. Two faults, called Fault A and Fault B, can trigger
recoverable fault actions on the compare channels CC0 and CC1 of the TCC. The compare channels'
outputs can be clamped to inactive state either as long as the fault condition is present, or from the first
valid fault condition detection on until the end of the timer/counter cycle.
Fault Inputs
The first two channel input events (TCCxMC0 and TCCxMC1) can be used as Fault A and Fault B inputs,
respectively. Event system channels connected to these fault inputs must be configured as
asynchronous. The TCC must work in a PWM mode.
Fault Filtering
There are three filters available for each input Fault A and Fault B. They are configured by the
corresponding Recoverable Fault n Configuration registers (FCTRLA and FCTRLB). The three filters can
either be used independently or in any combination.
Input
Filtering
By default, the event detection is asynchronous. When the event occurs, the fault system
will immediately and asynchronously perform the selected fault action on the compare
channel output, also in device power modes where the clock is not available. To avoid false
fault detection on external events (e.g. due to a glitch on an I/O port) a digital filter can be
enabled and configured by the Fault B Filter Value bits in the Fault n Configuration registers
(FCTRLn.FILTERVAL). If the event width is less than FILTERVAL (in clock cycles), the
event will be discarded. A valid event will be delayed by FILTERVAL clock cycles.
Fault
Blanking
This ignores any fault input for a certain time just after a selected waveform output edge.
This can be used to prevent false fault triggering due to signal bouncing, as shown in the
figure below. Blanking can be enabled by writing an edge triggering configuration to the
Fault n Blanking Mode bits in the Recoverable Fault n Configuration register
Atmel SAM L22G / L22J / L22N [DATASHEET]
Atmel-42402E-SAM L22G / L22J / L22N_Datasheet_Complete-07/2016
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