•
Normal Pulse-Width Modulation (NPWM)
•
Dual-slope, interrupt/event at TOP (DSTOP)
•
Dual-slope, interrupt/event at ZERO (DSBOTTOM)
•
Dual-slope, interrupt/event at Top and ZERO (DSBOTH)
•
Dual-slope, critical interrupt/event at ZERO (DSCRITICAL)
When using MFRQ configuration, the TOP value is defined by the CC0 register value. For the other
waveform operations, the TOP value is defined by the Period (PER) register value.
For dual-slope waveform operations, the update time occurs when the counter reaches ZERO. For the
other waveforms generation modes, the update time occurs on counter wraparound, on overflow,
underflow, or re-trigger.
The table below shows the update counter and overflow event/interrupt generation conditions in different
operation modes.
Table 36-2. Counter Update and Overflow Event/interrupt Conditions
Name
Operation
TOP
Update
Output Waveform
OVFIF/Event
On Match
On Update Up
Down
NFRQ
Normal
Frequency
PER
TOP/
ZERO
Toggle
Stable
TOP
ZERO
MFRQ
Match
Frequency
CC0
TOP/
ZERO
Toggle
Stable
TOP
ZERO
NPWM
Single-
slope PWM
PER
TOP/
ZERO
See section 'Output
Polarity' below
TOP
ZERO
DSCRITICAL
Dual-slope
PWM
PER
ZERO
-
ZERO
DSBOTTOM
Dual-slope
PWM
PER
ZERO
-
ZERO
DSBOTH
Dual-slope
PWM
PER
TOP
ZERO
TOP
ZERO
DSTOP
Dual-slope
PWM
PER
ZERO
TOP
–
1.
The UPDATE condition on TOP only will occur when circular buffer is enabled for the channel.
Related Links
on page 812
on page 538
Normal Frequency (NFRQ)
For Normal Frequency generation, the period time (T) is controlled by the period register (PER). The
waveform generation output (WO[x]) is toggled on each compare match between COUNT and CCx, and
the corresponding Match or Capture Channel x Interrupt Flag (EVCTRL.MCEOx) will be set.
Atmel SAM L22G / L22J / L22N [DATASHEET]
Atmel-42402E-SAM L22G / L22J / L22N_Datasheet_Complete-07/2016
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