User's Manual

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Controlling Multiple Buck Converters With Independent Frequencies
Example 3-1. Configuration for Example in Figure 3-4
//=====================================================================
// (Note: code for only 3 modules shown)
// Initialization Time
//========================
// EPWM Module 1 config
EPwm1Regs.TBPRD = 1200; // Period = 1201 TBCLK counts
EPwm1Regs.TBPHS = 0; // Set Phase register to zero
EPwm1Regs.TBCTL.bit.CTRMODE = TB_COUNT_UP; // Asymmetrical mode
EPwm1Regs.TBCTL.bit.PHSEN = TB_DISABLE; // Phase loading disabled
EPwm1Regs.TBCTL.bit.PRDLD = TB_SHADOW;
EPwm1Regs.TBCTL.bit.SYNCOSEL = TB_SYNC_DISABLE;
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.PRD = AQ_CLEAR;
EPwm1Regs.AQCTLA.bit.CAU = AQ_SET;
// EPWM Module 2 config
EPwm2Regs.TBPRD = 1400; // Period = 1401 TBCLK counts
EPwm2Regs.TBPHS = 0; // Set Phase register to zero
EPwm2Regs.TBCTL.bit.CTRMODE = TB_COUNT_UP; // Asymmetrical mode
EPwm2Regs.TBCTL.bit.PHSEN = TB_DISABLE; // Phase loading disabled
EPwm2Regs.TBCTL.bit.PRDLD = TB_SHADOW;
EPwm2Regs.TBCTL.bit.SYNCOSEL = TB_SYNC_DISABLE;
EPwm2Regs.CMPCTL.bit.SHDWAMODE = CC_SHADOW;
EPwm2Regs.CMPCTL.bit.SHDWBMODE = CC_SHADOW;
EPwm2Regs.CMPCTL.bit.LOADAMODE = CC_CTR_ZERO; // load on CTR=Zero
EPwm2Regs.CMPCTL.bit.LOADBMODE = CC_CTR_ZERO; // load on CTR=Zero
EPwm2Regs.AQCTLA.bit.PRD = AQ_CLEAR;
EPwm2Regs.AQCTLA.bit.CAU = AQ_SET;
// EPWM Module 3 config
EPwm3Regs.TBPRD = 800; // Period = 801 TBCLK counts
EPwm3Regs.TBPHS = 0; // Set Phase register to zero
EPwm3Regs.TBCTL.bit.CTRMODE = TB_COUNT_UP;
EPwm3Regs.TBCTL.bit.PHSEN = TB_DISABLE; // Phase loading disabled
EPwm3Regs.TBCTL.bit.PRDLD = TB_SHADOW;
EPwm3Regs.TBCTL.bit.SYNCOSEL = TB_SYNC_DISABLE;
EPwm3Regs.CMPCTL.bit.SHDWAMODE = CC_SHADOW;
EPwm3Regs.CMPCTL.bit.SHDWBMODE = CC_SHADOW;
EPwm3Regs.CMPCTL.bit.LOADAMODE = CC_CTR_ZERO; // load on CTR=Zero
EPwm3Regs.CMPCTL.bit.LOADBMODE = CC_CTR_ZERO; // load on CTR=Zero
EPwm3Regs.AQCTLA.bit.PRD = AQ_CLEAR;
EPwm3Regs.AQCTLA.bit.CAU = AQ_SET;
//
// Run Time (Note: Example execution of one run-time instant)
//=========================================================
EPwm1Regs.CMPA.half.CMPA = 700; // adjust duty for output EPWM1A
EPwm2Regs.CMPA.half.CMPA = 700; // adjust duty for output EPWM2A
EPwm3Regs.CMPA.half.CMPA = 500; // adjust duty for output EPWM3A
74 Applications to Power Topologies SPRU791D – November 2004 – Revised October 2007
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