Texas Instruments TMS320x28xx, 28xxx manual EPWMxB-Active Low, Action-Qualifier AQ Submodule

Models: 28xxx TMS320x28xx

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EPWMxB—Active Low

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Action-Qualifier (AQ) Submodule

Figure 2-22. Up, Single Edge Asymmetric Waveform With Independent Modulation on EPWMxA and

EPWMxB—Active Low

TBCTR

 

 

 

 

TBPRD

 

 

 

 

value

 

 

 

 

P

CA

P

CA

P

EPWMxA

P

EPWMxB

CB

P

CB

P

APWM period = (TBPRD + 1 ) × TTBCLK

BDuty modulation for EPWMxA is set by CMPA, and is active low (that is, the low time duty is proportional to CMPA).

CDuty modulation for EPWMxB is set by CMPB and is active low (that is, the low time duty is proportional to CMPB).

DThe Do Nothing actions ( X ) are shown for completeness here, but will not be shown on subsequent diagrams.

EActions at zero and period, although appearing to occur concurrently, are actually separated by one TBCLK period. TBCTR wraps from period to 0000.

Example 2-3contains a code sample showing initialization and run time for the waveforms in Figure 2-22.

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ePWM Submodules

SPRU791D–November 2004–Revised October 2007

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Page 44
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Texas Instruments TMS320x28xx, 28xxx manual EPWMxB-Active Low, Action-Qualifier AQ Submodule