Up, Single Edge Asymmetric Waveform, With Independent Modulation On Epwmxa And Epwmxb-Active High - Texas Instruments Concerto F28M35 Series Technical Reference Manual

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Figure 7-24. Up, Single Edge Asymmetric Waveform, With Independent Modulation on EPWMxA and
TBCTR
TBPRD
value
Z P
EPWMxA
Z P
EPWMxB
A PWM period = (TBPRD + 1 ) × T
B Duty modulation for EPWMxA is set by CMPA, and is active high (that is, high time duty proportional to CMPA).
C Duty modulation for EPWMxB is set by CMPB and is active high (that is, high time duty proportional to CMPB).
D The "Do Nothing" actions ( X ) are shown for completeness, but will not be shown on subsequent diagrams.
E Actions at zero and period, although appearing to occur concurrently, are actually separated by one TBCLK period.
TBCTR wraps from period to 0000.
Example 7-1 contains a code sample showing initialization and run time for the waveforms in
Example 7-1. Code Sample for
// Initialization Time
// = = = = = = = = = = = = = = = = = = = = = = = =
EPwm1Regs.TBPRD = 600;
EPwm1Regs.CMPA.half.CMPA = 350;
EPwm1Regs.CMPB = 200;
EPwm1Regs.TBPHS = 0;
EPwm1Regs.TBCTR = 0;
EPwm1Regs.TBCTL.bit.CTRMODE = TB_COUNT_UP;
EPwm1Regs.TBCTL.bit.PHSEN = TB_DISABLE;
EPwm1Regs.TBCTL.bit.PRDLD = TB_SHADOW;
EPwm1Regs.TBCTL.bit.SYNCOSEL = TB_SYNC_DISABLE;
EPwm1Regs.TBCTL.bit.HSPCLKDIV = TB_DIV1;
EPwm1Regs.TBCTL.bit.CLKDIV = TB_DIV1;
EPwm1Regs.CMPCTL.bit.SHDWAMODE = CC_SHADOW;
EPwm1Regs.CMPCTL.bit.SHDWBMODE = CC_SHADOW;
EPwm1Regs.CMPCTL.bit.LOADAMODE = CC_CTR_ZERO; // load on CTR = Zero
EPwm1Regs.CMPCTL.bit.LOADBMODE = CC_CTR_ZERO; // load on CTR = Zero
EPwm1Regs.AQCTLA.bit.ZRO = AQ_SET;
EPwm1Regs.AQCTLA.bit.CAU = AQ_CLEAR;
EPwm1Regs.AQCTLB.bit.ZRO = AQ_SET;
EPwm1Regs.AQCTLB.bit.CBU = AQ_CLEAR;
//
// Run Time
// = = = = = = = = = = = = = = = = = = = = = = = =
EPwm1Regs.CMPA.half.CMPA = Duty1A;
SPRUH22I – April 2012 – Revised November 2019
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EPWMxB—Active High
CB CA
CB CA
TBCLK
Figure 7-24
// Period = 601 TBCLK counts
// Compare A = 350 TBCLK counts
// Compare B = 200 TBCLK counts
// Set Phase register to zero
// clear TB counter
// Phase loading disabled
// TBCLK = SYSCLK
// adjust duty for output EPWM1A
Copyright © 2012–2019, Texas Instruments Incorporated
Z P CB
Z P CB
C28 Enhanced Pulse Width Modulator (ePWM) Module
ePWM Submodules
CA Z P
CA Z P
Figure 7-24.
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