Datasheet

• 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 31-2. 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
(1)
&
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
31.6.3.2 Circular Buffer
23. PORT - I/O Pin Controller
31.6.2.5.2 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.
SAM D21 Family
TCC – Timer/Counter for Control Applications
© 2018 Microchip Technology Inc.
Datasheet Complete
DS40001882D-page 714