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工具与软件:
您好!
我需要能够使用 DMA 运行 ePWM 模块、但 速度要快两倍。 后台情况是、我想使用 DMA 更新 ePWM 模块、以实现中心对齐的 PWM。
FOC (场定向控制)使用大约20kHz 完成、PWM 为40kHz。 现在、要计算高速应用的相位延迟、DMA 应该已经包含4组 PWM。 因此、我也希望中心对齐 PWM 的更新位于中间。
我已经在 TI 示例中尝试了 epwm_ex9_dma 示例、但我无法实现。 有什么想法如何做到这一点吗?
EDIT1: 我曾在第一步尝试在每个 PWM 周期中更新 DMA、并将 FOC ISR 的速度减半、但无法实现:
EPWM INIT (来自通用电机控制):
// USER_M1_NUM_PWM_TICKS_PER_ISR_TICK = 2 uint16_t pwmPeriodCycles = (uint16_t)(USER_M1_PWM_TBPRD_NUM); uint16_t pwmPeriodBCCycles = (uint16_t)(USER_M1_BC_TBPRD_NUM); uint16_t numPWMTicksPerISRTick = USER_M1_NUM_PWM_TICKS_PER_ISR_TICK; // setup the Time-Base Control Register (TBCTL) EPWM_setTimeBaseCounterMode(obj->pwmHandle[cnt], EPWM_COUNTER_MODE_UP_DOWN); EPWM_disablePhaseShiftLoad(obj->pwmHandle[cnt]); // EPWM_setPeriodLoadMode(obj->pwmHandle[cnt], EPWM_PERIOD_SHADOW_LOAD); //EPWM_PERIOD_SHADOW_LOAD //EPWM_PERIOD_DIRECT_LOAD EPWM_setPeriodLoadMode(obj->pwmHandle[cnt], EPWM_PERIOD_SHADOW_LOAD); //EPWM_PERIOD_SHADOW_LOAD //EPWM_PERIOD_DIRECT_LOAD EPWM_enableSyncOutPulseSource(obj->pwmHandle[cnt], EPWM_SYNC_OUT_PULSE_ON_SOFTWARE); EPWM_setClockPrescaler(obj->pwmHandle[cnt], EPWM_CLOCK_DIVIDER_1, EPWM_HSCLOCK_DIVIDER_1); EPWM_setCountModeAfterSync(obj->pwmHandle[cnt], EPWM_COUNT_MODE_UP_AFTER_SYNC); EPWM_setEmulationMode(obj->pwmHandle[cnt], EPWM_EMULATION_FREE_RUN); // setup the Timer-Based Phase Register (TBPHS) EPWM_setPhaseShift(obj->pwmHandle[cnt], 0); // setup the Time-Base Counter Register (TBCTR) EPWM_setTimeBaseCounter(obj->pwmHandle[cnt], 0); // setup the Time-Base Period Register (TBPRD) // set to zero initially EPWM_setTimeBasePeriod(obj->pwmHandle[cnt], 0); // setup the Counter-Compare Control Register (CMPCTL) EPWM_setCounterCompareShadowLoadMode(obj->pwmHandle[cnt], EPWM_COUNTER_COMPARE_A, EPWM_COMP_LOAD_ON_CNTR_ZERO); //EPWM_COMP_LOAD_ON_CNTR_ZERO EPWM_setCounterCompareShadowLoadMode(obj->pwmHandle[cnt], EPWM_COUNTER_COMPARE_B, EPWM_COMP_LOAD_ON_CNTR_ZERO); EPWM_setCounterCompareShadowLoadMode(obj->pwmHandle[cnt], EPWM_COUNTER_COMPARE_C, EPWM_COMP_LOAD_ON_CNTR_ZERO); EPWM_setCounterCompareShadowLoadMode(obj->pwmHandle[cnt], EPWM_COUNTER_COMPARE_D, EPWM_COMP_LOAD_ON_CNTR_ZERO); // setup the Action-Qualifier Output A Register (AQCTLA) EPWM_setActionQualifierAction(obj->pwmHandle[cnt], EPWM_AQ_OUTPUT_A, EPWM_AQ_OUTPUT_HIGH, EPWM_AQ_OUTPUT_ON_TIMEBASE_UP_CMPA); EPWM_setActionQualifierAction(obj->pwmHandle[cnt], EPWM_AQ_OUTPUT_A, EPWM_AQ_OUTPUT_HIGH, EPWM_AQ_OUTPUT_ON_TIMEBASE_PERIOD); EPWM_setActionQualifierAction(obj->pwmHandle[cnt], EPWM_AQ_OUTPUT_A, EPWM_AQ_OUTPUT_LOW, EPWM_AQ_OUTPUT_ON_TIMEBASE_DOWN_CMPA); EPWM_setActionQualifierAction(obj->pwmHandle[cnt], EPWM_AQ_OUTPUT_A, EPWM_AQ_OUTPUT_LOW, EPWM_AQ_OUTPUT_ON_TIMEBASE_ZERO); // setup the Dead-Band Generator Control Register (DBCTL) EPWM_setDeadBandDelayMode(obj->pwmHandle[cnt], EPWM_DB_RED, true); EPWM_setDeadBandDelayMode(obj->pwmHandle[cnt], EPWM_DB_FED, true); // select EPWMA as the input to the dead band generator EPWM_setRisingEdgeDeadBandDelayInput(obj->pwmHandle[cnt], EPWM_DB_INPUT_EPWMA); // configure the right polarity for active high complementary config. EPWM_setDeadBandDelayPolarity(obj->pwmHandle[cnt], EPWM_DB_RED, EPWM_DB_POLARITY_ACTIVE_HIGH); EPWM_setDeadBandDelayPolarity(obj->pwmHandle[cnt], EPWM_DB_FED, EPWM_DB_POLARITY_ACTIVE_LOW); // setup the Dead-Band Rising Edge Delay Register (DBRED) EPWM_setRisingEdgeDelayCount(obj->pwmHandle[cnt], MTR1_PWM_DBRED_CNT); // setup the Dead-Band Falling Edge Delay Register (DBFED) EPWM_setFallingEdgeDelayCount(obj->pwmHandle[cnt], MTR1_PWM_DBFED_CNT); // setup the PWM-Chopper Control Register (PCCTL) EPWM_disableChopper(obj->pwmHandle[cnt]); // setup the Trip Zone Select Register (TZSEL) EPWM_disableTripZoneSignals(obj->pwmHandle[cnt], HAL_TZSEL_SIGNALS_ALL); // setup the Event Trigger Selection Register (ETSEL) EPWM_setInterruptSource(obj->pwmHandle[0], EPWM_INT_TBCTR_ZERO); //EPWM_INT_TBCTR_ZERO EPWM_enableInterrupt(obj->pwmHandle[0]); //Initial ADC trigger --> used for FOC EPWM_setADCTriggerSource(obj->pwmHandle[0], EPWM_SOC_A, EPWM_SOC_TBCTR_D_CMPC); //EPWM_SOC_TBCTR_D_CMPC EPWM_enableADCTrigger(obj->pwmHandle[0], EPWM_SOC_A); EPWM_setInterruptEventCount(obj->pwmHandle[0], numPWMTicksPerISRTick); EPWM_setADCTriggerEventPrescale(obj->pwmHandle[0], EPWM_SOC_A, numPWMTicksPerISRTick); EPWM_setADCTriggerEventPrescale(obj->pwmHandle[0], EPWM_SOC_B, numPWMTicksPerISRTick); // setup the Event Trigger Clear Register (ETCLR) EPWM_clearEventTriggerInterruptFlag(obj->pwmHandle[0]); EPWM_clearADCTriggerFlag(obj->pwmHandle[0], EPWM_SOC_A); EPWM_clearADCTriggerFlag(obj->pwmHandle[0], EPWM_SOC_B); // since the PWM is configured as an up/down counter, the period register is // set to one-half of the desired PWM period EPWM_setTimeBasePeriod(obj->pwmHandle[0], pwmPeriodCycles); EPWM_setTimeBasePeriod(obj->pwmHandle[1], pwmPeriodCycles); EPWM_setTimeBasePeriod(obj->pwmHandle[2], pwmPeriodCycles); // write the PWM data value for ADC trigger EPWM_setCounterCompareValue(obj->pwmHandle[0], EPWM_COUNTER_COMPARE_C, 10);
DMA 初始化:
// // DMA CH4 // DMA_configAddresses(DMA_CH4_BASE, (uint16_t *)(MTR1_PWM_U_BASE + EPWM_O_CMPA), dma_epwm_config.dmaConfigsCycleU); DMA_configBurst(DMA_CH4_BASE, 2, 1, 1); //4 bursts --> One for for each up and down of the center aligned PWM DMA_configTransfer(DMA_CH4_BASE, 1, 1, -2); //4 Transfers, CMPAHR , CMPA , CMPBHR , CMPB DMA_configMode(DMA_CH4_BASE, DMA_TRIGGER_EPWM1SOCA, DMA_CFG_ONESHOT_DISABLE | DMA_CFG_CONTINUOUS_ENABLE | DMA_CFG_SIZE_16BIT); // // DMA CH5 // DMA_configAddresses(DMA_CH5_BASE, (uint16_t *)(MTR1_PWM_V_BASE + EPWM_O_CMPA), dma_epwm_config.dmaConfigsCycleV); DMA_configBurst(DMA_CH5_BASE, 2, 1, 1); //4 bursts --> One for for each up and down of the center aligned PWM DMA_configTransfer(DMA_CH5_BASE, 1, 1, -2); //4 Transfers, CMPAHR , CMPA , CMPBHR , CMPB DMA_configMode(DMA_CH5_BASE, DMA_TRIGGER_EPWM1SOCA, DMA_CFG_ONESHOT_DISABLE | DMA_CFG_CONTINUOUS_ENABLE | DMA_CFG_SIZE_16BIT); //Every channel triggers on the 1SOCA or same trigger // // DMA CH6 // DMA_configAddresses(DMA_CH6_BASE, (uint16_t *)(MTR1_PWM_W_BASE + EPWM_O_CMPA), dma_epwm_config.dmaConfigsCycleW); DMA_configBurst(DMA_CH6_BASE, 2, 1, 1); //4 bursts --> One for for each up and down of the center aligned PWM DMA_configTransfer(DMA_CH6_BASE, 1, 1, -2); //4 Transfers, CMPAHR , CMPA , CMPBHR , CMPB DMA_configMode(DMA_CH6_BASE, DMA_TRIGGER_EPWM1SOCA, DMA_CFG_ONESHOT_DISABLE | DMA_CFG_CONTINUOUS_ENABLE | DMA_CFG_SIZE_16BIT); DMA_enableTrigger(DMA_CH6_BASE); //Start DMA_startChannel(DMA_CH4_BASE); DMA_startChannel(DMA_CH5_BASE); DMA_startChannel(DMA_CH6_BASE);
谢谢
尊敬的 Hans:
这些是 DMA 触发源。 如果您希望在 PWM 周期内生成两个 DMA 传输、您应该从 PWM 配置另一个 SOC 事件、并使用另一个 DMA 通道将此触发作为源。 当 TBCTR =CMPC 发生递减事件时、低字节片段可以从 PWM 生成 SOC_A。
您可以生成另一个触发来针对 TBCTR =CMPC 递增事件生成 SOC_B。 然后、您将需要配置另一个 DMA 通道。
//初始 ADC 触发-->用于 FOC
ePWM_setADCTriggerSource (obj->pwmHandle[0]、ePWM_SOC_A、ePWM_SOC_TBCTR_D_CMPC);//ePWM_SOC_TBCTR_D_CMPC
ePWM_enableADCTrigger (obj->pwmHandle[0]、ePWM_SOC_A);