Part Number: TMS320C28346
Tool/software: Code Composer Studio
Hi to everyone,
I have three cascaded ePWM modules, which they are synchronized -and dephased- with one another. I want the first PWM to be synchronized to software
More specifically: everytime the angle produced by a PLL resets, I want to create an software event in ePWM1, which then will synchronize accordingly the other two ePWMs.
The PLL itself and the resetting function are programmed in C++.
I have also written a class for setting up the PWMs. Voila:
Firing::Firing(volatile struct EPWM_REGS *APwmRegs, unsigned int PWM_PRD, unsigned int PWM_PHASE, bool PWM_SYNC)
{
ThePwm=APwmRegs;
EALLOW;
SysCtrlRegs.PCLKCR0.bit.TBCLKSYNC = 0; // Disable ePWM clocks
EDIS;
ThePwm->TBPRD=PWM_PRD; // Set timer period
ThePwm->TBCTR = 0; // clear-reset TB counter to 0
ThePwm->CMPA.half.CMPA = ThePwm->TBPRD; // initial duty ratio for CMPA (RS+,ST+,TR+)
ThePwm->CMPB = 0; // initial duty ratio for CMPB (RS-,ST-,TR-)
ThePwm->TBPHS.half.TBPHS = PWM_PHASE; // phase register value
ThePwm->TBCTL.bit.CTRMODE=TB_COUNT_UP; // set triangular waveform as count up
ThePwm->TBCTL.bit.PHSEN = TB_ENABLE; // enable loading phase register value
ThePwm->TBCTL.bit.SYNCOSEL= TB_SYNC_IN; // synchronization
ThePwm->TBCTL.bit.PRDLD=TB_SHADOW; // enable shadow register for period register
ThePwm->CMPCTL.bit.SHDWAMODE=CC_SHADOW; // enable Shadows for CMPA
ThePwm->CMPCTL.bit.SHDWBMODE=CC_SHADOW; // enable Shadows for CMPB
ThePwm->CMPCTL.bit.LOADAMODE=CC_CTR_ZERO; // load reference for ePWMA - on ZERO
ThePwm->CMPCTL.bit.LOADBMODE=CC_CTR_ZERO; // load reference for ePWMB - on ZERO
//TBCLK = SYSCLKOUT / (HSPCLKDIV * CLKDIV) = 300MHz / (12 * 8) = 3.125MHz
ThePwm->TBCTL.bit.HSPCLKDIV = 0x6; //HSPCLKDIV: divide by 12
ThePwm->TBCTL.bit.CLKDIV = 0x3; // CLKDIV: divide by 8
// disable action qualifier - AQ_NO_ACTION
ThePwm->AQCTLA.bit.CAU = AQ_NO_ACTION;
ThePwm->AQCTLB.bit.CBU = AQ_NO_ACTION;
ThePwm->ETSEL.bit.INTEN = 1; // enable ePWM Interrupts
ThePwm->ETPS.bit.INTPRD = ET_1ST; // number of events needed to generate an interrupt (here: every event)
ThePwm->ETSEL.bit.INTSEL = ET_CTR_ZERO; // when active trigger interrupt at ZERO
ThePwm->ETCLR.bit.INT = 1; // clear the INT flag if any
EALLOW;
SysCtrlRegs.PCLKCR0.bit.TBCLKSYNC = 1; // Enable ePWM clocks
EDIS;
}
void Firing::Synchronize(bool zeroCrossing_)
{
ThePwm->TBCTL.bit.SWFSYNC = zeroCrossing_; //zero crossing is a function that returns 1 or 0 every time the angle resets (from 2pi to 0 again)
}
Could you please indicate possible reasons for which I don't manage to create the SWFSYNC event?
