SAM3A8C Atmel Corporation, SAM3A8C Datasheet - Page 990

• Manufacturer Part Number: SAM3A8C
• Manufacturer: Atmel Corporation

990
990
SAM3X/A
SAM3X/A
Figure 38-4. Non Overlapped Center Aligned Waveforms
Note:
When center aligned, the channel counter increases up to CPRD and decreases down to 0. This
ends the period.
When left aligned, the channel counter increases up to CPRD and is reset. This ends the period.
Thus, for the same CPRD value, the period for a center aligned channel is twice the period for a
left aligned channel.
Waveforms are fixed at 0 when:
Waveforms are fixed at 1 (once the channel is enabled) when:
The waveform polarity must be set before enabling the channel. This immediately affects the
channel output level. Changes on channel polarity are not taken into account while the channel
is enabled.
• the waveform polarity. At the beginning of the period, the signal can be at high or low level.
• the waveform alignment. The output waveform can be left or center aligned. Center aligned
• CDTY = CPRD and CPOL = 0
• CDTY = 0 and CPOL = 1
• CDTY = 0 and CPOL = 0
• CDTY = CPRD and CPOL = 1
If the waveform is left aligned then:
If the waveform is center aligned, then:
This property is defined in the CPOL field of the PWM_CMRx register. By default the signal
starts by a low level.
waveforms can be used to generate non overlapped waveforms. This property is defined in
the CALG field of the PWM_CMRx register. The default mode is left aligned.
duty cycle
duty cycle
OC0
OC1
1. See
Figure 38-5 on page 992
=
=
No overlap
----------------------------------------------------------------------------------------------------------- -
----------------------------------------------------------------------------------------------------------------------------- -
period 1
period
Period
–
2
fchannel_x_clock
–
1
period
period
fchannel_x_clock
for a detailed description of center aligned waveforms.
2
CDTY
CDTY
11057A–ATARM–17-Feb-12
11057A–ATARM–17-Feb-12