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Controlling Multiple Buck Converters With Same Frequencies
Example 3-2. Code Snippet for Configuration in Figure 3-5
//=====================================================================
// Config
//=====================================================================
// Initialization Time
//========================
// EPWM Module 1 config
EPwm1Regs.TBPRD = 600; // Period = 1200 TBCLK counts
EPwm1Regs.TBPHS = 0; // Set Phase register to zero
EPwm1Regs.TBCTL.bit.CTRMODE = TB_COUNT_UPDOWN; // Symmetrical mode
EPwm1Regs.TBCTL.bit.PHSEN = TB_DISABLE; // Master module
EPwm1Regs.TBCTL.bit.PRDLD = TB_SHADOW;
EPwm1Regs.TBCTL.bit.SYNCOSEL = TB_CTR_ZERO; // Sync down-stream module
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.CAU = AQ_SET; // set actions for EPWM1A
EPwm1Regs.AQCTLA.bit.CAD = AQ_CLEAR;
EPwm1Regs.AQCTLB.bit.CBU = AQ_SET; // set actions for EPWM1B
EPwm1Regs.AQCTLB.bit.CBD = AQ_CLEAR;
// EPWM Module 2 config
EPwm2Regs.TBPRD = 600; // Period = 1200 TBCLK counts
EPwm2Regs.TBPHS = 0; // Set Phase register to zero
EPwm2Regs.TBCTL.bit.CTRMODE = TB_COUNT_UPDOWN; // Symmetrical mode
EPwm2Regs.TBCTL.bit.PHSEN = TB_ENABLE; // Slave module
EPwm2Regs.TBCTL.bit.PRDLD = TB_SHADOW;
EPwm2Regs.TBCTL.bit.SYNCOSEL = TB_SYNC_IN; // sync flow-through
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.CAU = AQ_SET; // set actions for EPWM2A
EPwm2Regs.AQCTLA.bit.CAD = AQ_CLEAR;
EPwm2Regs.AQCTLB.bit.CBU = AQ_SET; // set actions for EPWM2B
EPwm2Regs.AQCTLB.bit.CBD = AQ_CLEAR;
//
// Run Time (Note: Example execution of one run-time instance)
//===========================================================
EPwm1Regs.CMPA.half.CMPA = 400; // adjust duty for output EPWM1A
EPwm1Regs.CMPB = 200; // adjust duty for output EPWM1B
EPwm2Regs.CMPA.half.CMPA = 500; // adjust duty for output EPWM2A
EPwm2Regs.CMPB = 300; // adjust duty for output EPWM2B
SPRU791D – November 2004 – Revised October 2007 Applications to Power Topologies 77
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