Tool/software:
Hi expert,
Using F28069, we found when the duty cycle changes from non-0% to 0%, the EPWM4B output high lever for 1 PWM cycle. What could be the potential issue?
Configuration: configure the PWM switching period to 38.4K, trigger the PWM interrupt at the zero-crossing point, and configure the PWM interrupt to be triggered once every 2 PWM zero crossing events (EPwm4Regs.ETPS.bit.INTPRD = 2). Execute the control algorithm in the interrupt function and change the PWM comparison value.
Here is the configuration code:
EPwm4Regs.CMPCTL.bit.SHDWAMODE = 0; // Compare A Register Shadow mode
EPwm4Regs.CMPCTL.bit.SHDWBMODE = 0; // Compare B Register Shadow mode
EPwm4Regs.CMPCTL.bit.LOADAMODE = 0; // Load on CTR = ZERO
EPwm4Regs.CMPCTL.bit.LOADBMODE = 0; // Load on CTR = ZERO
EPwm4Regs.AQCTLA.all = 0;
EPwm4Regs.AQCTLB.all = 0;
EPwm4Regs.AQCTLA.bit.CAU = 2;
EPwm4Regs.AQCTLA.bit.CAD = 1;
EPwm4Regs.AQCTLA.bit.PRD = 2;
EPwm4Regs.AQCTLA.bit.ZRO = 1;
EPwm4Regs.AQCTLB.bit.CAU = 2;
EPwm4Regs.AQCTLB.bit.CAD = 1;
EPwm4Regs.AQCTLB.bit.PRD = 2;
EPwm4Regs.AQCTLB.bit.ZRO = 1;
EPwm4Regs.ETSEL.bit.INTEN = 1; // Enable EPWMxINT generation
EPwm4Regs.ETSEL.bit.INTSEL = 1; // Enable CTR = zero event
EPwm4Regs.ETSEL.bit.SOCAEN = 1; // Enable SOCA pulse
EPwm4Regs.ETSEL.bit.SOCASEL = 3; // Enable CTR = zero event
EPwm4Regs.ETPS.bit.INTPRD = 2; // generate interrupt on INTCNT=01(first event) trigger 1 interrupt every 2 cross zero events
EPwm4Regs.ETPS.bit.SOCAPRD = 1; // Generate pulse on SOCACNT=01(first event)
Please help with some suggestions, thanks!
Joyce
