Datasheet

Figure 18-3. Cycle presentation in Centered mode.
One PS C cycle
UPDATE
PS C counter value
The figures above graphically illustrate the values held in the PSC counter. Centered mode is like One
Ramp mode which counts down and then up.
Notice that the update of the waveform generator registers is done regardless of ramp mode at the end of
the PSC cycle.
18.5.3. Operation mode descriptions
Waveforms and duration of output signals are determined by parameters held in the registers (POCRnSA,
POCRnRA, POCRnSB, POCR_RB) and by the running mode. Two modes are possible:
• One Ramp Mode. In this mode, all the three PSCOUTnB outputs are edge-aligned and the three
PSCOUTnA can be also edge-aligned when setting the same values in the dedicated registers.
In this mode, the PWM frequency is twice the Center Aligned mode PWM frequency
• Center Aligned Mode. In this mode, all the six PSC outputs are aligned at the center of the period.
Except when using the same duty cycles on the three modules, the edges of the outputs are not
aligned. So the PSC outputs do not commute at the same time, thus the system which is driven by
these outputs will generate less commutation noise.
In this mode, the PWM frequency is twice as slow as in One Ramp mode
18.5.3.1. One Ramp mode (edge-aligned)
The following figure shows the resultant outputs PSCOUTnA and PSCOUTnB operating in one ramp
mode over a PSC cycle.
Atmel ATmega16M1/32M1/64M1 [DATASHEET]
Atmel-8209F-ATmega16M1/32M1/64M1_Datasheet_Complete-10/2016
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