TMS570LS1224: Syncing 3 EPWMs ,left aligned PWM based ADC conversion - Code example

Hi SB,

The ePWM modules are chained together via a clock synchronization scheme that allows them to operate as a single system when required. Each ePWM has a synchronization input (EPWMxSYNCI) and a synchronization output (EPWMxSYNCO). The input synchronization for the first instance (ePWM1) comes from an external pin. Each ePWM module can be configured to use or ignore the synchronization input.

You can also force a sync pulse (SWFSYNC) to OR the EPWMxSYNCI.

Hi QJ,

How do you configure PWMs as left aligned?

Hi QJ,

Could you please share any example code if you have any?

Hi Sachin,

Sorry I don't have example code.

Up-count mode.Do you have any example code for it?

_enable_interrupt_();
/* Setup ADCs */
adcStartConversion(adcREG1, adcGROUP1);
adcStartConversion(adcREG2, adcGROUP1);
kickerReg->KICKER0 = 0x83E70B13U;
kickerReg->KICKER1 = 0x95A4F1E0U;
pinMuxReg->PINMMR35 = 0x0000;
kickerReg->KICKER0 = 0x00000000U;
kickerReg->KICKER1 = 0x00000000U;
/* setup etPWM */
etpwmSetCount(etpwmREG1, 1000);
etpwmSetCount(etpwmREG2,500);
etpwmSetCount(etpwmREG3, 300);
etpwmSetCounterMode(etpwmREG1, CounterMode_UpDown);
etpwmSetCounterMode(etpwmREG2, CounterMode_UpDown);
etpwmSetCounterMode(etpwmREG3, CounterMode_UpDown);
etpwmSetSyncOut(etpwmREG1,SyncOut_CtrEqZero);
etpwmSetSyncOut(etpwmREG2,SyncOut_EPWMxSYNCI);
etpwmSetSyncOut(etpwmREG3,SyncOut_EPWMxSYNCI);
etpwmREG2->TBCTL |= (uint16)2U << 1U; // PHSEN
etpwmREG3->TBCTL |= (uint16)2U << 1U;
/* Configure mthe module to set PWMA value as 1 when CTR=0 and as 0 when CTR=CmpA */
etpwmActionQualConfig_t configPWM;
configPWM.CtrEqPeriod_Action = ActionQual_Disabled;
configPWM.CtrEqZero_Action = ActionQual_Disabled;
configPWM.CtrEqCmpAUp_Action = ActionQual_Set;
configPWM.CtrEqCmpADown_Action = ActionQual_Clear;
configPWM.CtrEqCmpBUp_Action = ActionQual_Disabled;
configPWM.CtrEqCmpBDown_Action = ActionQual_Disabled;
etpwmSetActionQualPwmA(etpwmREG1, configPWM);
etpwmSetActionQualPwmA(etpwmREG2, configPWM);
etpwmSetActionQualPwmA(etpwmREG3, configPWM);
/* Enable trigger for SOC */
etpwmEnableSOCA(etpwmREG1, CTR_ZERO, EventPeriod_FirstEvent);
etpwmClearEventFlag(etpwmREG1, Event_SOCA);
etpwmTriggerEvent(etpwmREG1,Event_SOCA);
etpwmDisableCounterLoadOnSync(etpwmREG1);
etpwmEnableCounterLoadOnSync(etpwmREG2, 0, 0x2000);
etpwmEnableCounterLoadOnSync(etpwmREG3, 0, 0x2000);
etpwmEnableTimebasePeriodShadowMode(etpwmREG1);
etpwmEnableTimebasePeriodShadowMode(etpwmREG2);
etpwmEnableTimebasePeriodShadowMode(etpwmREG3);
etpwmEnableCmpAShadowMode(etpwmREG1, LoadMode_CtrEqZero);
etpwmEnableCmpAShadowMode(etpwmREG2, LoadMode_CtrEqZero);
etpwmEnableCmpAShadowMode(etpwmREG3, LoadMode_CtrEqZero);
etpwmDeadBandConfig_t deadbandconfig;
deadbandconfig.halfCycleEnable = true;
deadbandconfig.inputmode = PWMA_RED_FED;
deadbandconfig.outputmode = PWMB_FED_PWMA_RED;
deadbandconfig.polarity = Invert_PWMB;
etpwmSetDeadBandDelay(etpwmREG1,112,112);
etpwmSetDeadBandDelay(etpwmREG2,112,112);
etpwmSetDeadBandDelay(etpwmREG3,112,112);
etpwmEnableDeadBand(etpwmREG1, deadbandconfig);
etpwmEnableDeadBand(etpwmREG2, deadbandconfig);
etpwmEnableDeadBand(etpwmREG3, deadbandconfig)

Do you think this will work? How can we verify?