Other Parts Discussed in Thread: CONTROLSUITE
Hi everyone,
I am using a F28027 Piccolo Launchpad and am now trying to implement a buck converter. I need to use the microcontroller to control the pwm duty cycle for buck controller. I followed the code from document SPRUGE9 page 82.
//initialazation
// EPWM Module 3 config
EPwm3Regs.TBPRD = 800; // Period = 801 TBCLK counts
EPwm3Regs.TBPHS.half.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;
//runtime
EPwm3Regs.CMPA.half.CMPA = 500; // adjust duty for output EPWM3A
However, there is no PWM output from either EPWM3A or EPWM3B. Is there any chance that I missed some part of the codes? Are there any potential problems that I might need to notice?
Thanks.
Jingzhe
