Specifications

© 2008-2012 Microchip Technology Inc. DS70323E-page 43-67
Section 43. High-Speed PWM
High-Speed PWM
43
43.9.4 True Independent PWM Output Mode
In True Independent PWM Output mode (PMOD = 11), the PWM outputs (PWMxH and PWMxL)
can have different duty cycles. The PDCx register specifies the duty cycle for the PWMxH output,
whereas the SDCx register specifies the duty cycle for the PWMxL output. In addition, the
PWMxH and PWMxL outputs can either have different periods or they can be phase-shifted
relative to each other.
• When ITB = 1, the PHASEx register specifies the PWM period for the PWMxH output and
the SPHASEx register specifies the PWM period for the PWMxL output
• When ITB = 0, the PHASEx register specifies the phase shift for the PWMxH output and
the SPHASEx register specifies the phase shift for the PWMxL output
Independent PWM Output mode is illustrated in Figure 43-32. PWM Output Pin mode selection
is shown in Example 43-19.
Figure 43-32: True Independent PWM Output Mode
Note: In Independent Time Base mode (ITB = 1), there may not be a deterministic phase
relationship between the PWMxH and PWMxL outputs.
Duty Cycle 2
PWMxL
Duty Cycle 1
PWMxH
Period
PMTMR = 0
Duty Cycle 2
PWMxL
Duty Cycle 1
PWMxH
Period
Phase 2
PMTMR = 0
Duty Cycle 2
PWMxL
Duty Cycle 1
PWMxH
Period 2
Period 1
.
Master Time Base
Phase = 0
SPHASE = 0
Master Time Base
ITB = 1
with Phase Shift