[参考译文] TMS320F280025C：3个 ePWM 之间的相移有问题

您可以看到另一个函数、用于根据所需的频率和占空比计算 TBPRD 和 CMPA。 很抱歉我的英语水平！ 如果我正确理解 TBPHS 最大值= TBPRD 最大值并且我确定这些值。 TBPRD 和 CMPA 正确。  

例如、如果我希望 PWM1和 PWM2之间的相移为90°、PWM1和 PWM3之间的相移为180°

=> TBPHS (主器件 PWM1)= 0

=> TBPHS (从器件 PWM2)=((相位= 90°)* TBPRD)/ 360；在我的案例中 TBPRD = 156、因此 TBPHS = 39

=> TBPHS (从器件 PWM3)=((相位= 180°)* TBPRD)/360在我的案例中 TBPRD = 156、因此 TBPHS = 78

可以帮帮我吗？ 我的错在哪里？  

谢谢

Damien

void set_phase(uint32_t base, uint16_t phi)
{
    uint16_t phase;

    if(base == myEPWM2_BASE)
    {
        phase = ((float)phi * HWREGH(base + EPWM_O_TBPRD) / 360);
    }

    if(base == myEPWM3_BASE)
    {
        phase = ((float)phi * HWREGH(base + EPWM_O_TBPRD) * 2 / 360);
    }

    //EPWM_selectPeriodLoadEvent(base, EPWM_SHADOW_LOAD_MODE_SYNC);
    EPWM_enableSyncOutPulseSource(base, EPWM_SYNC_OUT_PULSE_ON_SOFTWARE);
    EPWM_forceSyncPulse(base);

    EPWM_setPhaseShift(base, phase);
    EPWM_setTimeBaseCounter(base, phase);
    EPWM_enablePhaseShiftLoad(base);
}

*TBPRD_boost_3 = PWM_Freq_TBCLK / (PWM_FREQ * 2);
*CMPA_boost_3 = ((float) (100 - duty_boost_3) / 100) * (*TBPRD_boost_3);

void epwm_init(uint32_t base)
{
    float PWM_TBPRD_1;
    float PWM_TBPRD_2;
    float PWM_TBPRD_3;
    float PWM_CMPA_1;
    float PWM_CMPA_2;
    float PWM_CMPA_3;
    EPWM_ClockDivider PWM_PARAM_PRESCALER;
    EPWM_HSClockDivider PWM_PARAM_HIGHSPEEDPRESCALER;
    float TBCLK;

    if(base == myEPWM1_BASE)
    {
        get_pwm_clock_from_freq(base , &PWM_TBPRD_1 , &PWM_TBPRD_2 , &PWM_TBPRD_3 , &PWM_CMPA_1 , &PWM_CMPA_2 , &PWM_CMPA_3 , &PWM_PARAM_PRESCALER , &PWM_PARAM_HIGHSPEEDPRESCALER, &TBCLK);

        // Parameters
        EPWM_setTimeBasePeriod(base, (uint16_t)PWM_TBPRD_1);
        EPWM_setCounterCompareValue(base, EPWM_COUNTER_COMPARE_B, (uint16_t)PWM_CMPA_1);
        EPWM_setPhaseShift(base, 0U);
        EPWM_disablePhaseShiftLoad(base);
        EPWM_setTimeBaseCounter(base, 0U);
        EPWM_enableSyncOutPulseSource(myEPWM1_BASE, EPWM_SYNC_OUT_PULSE_ON_CNTR_ZERO);
    }

    else if (base == myEPWM2_BASE)
    {
        get_pwm_clock_from_freq(base , &PWM_TBPRD_1 , &PWM_TBPRD_2 , &PWM_TBPRD_3 , &PWM_CMPA_1 , &PWM_CMPA_2 , &PWM_CMPA_3 , &PWM_PARAM_PRESCALER , &PWM_PARAM_HIGHSPEEDPRESCALER, &TBCLK);

        // Parameters
        EPWM_setTimeBasePeriod(base, (uint16_t)PWM_TBPRD_2);
        EPWM_setCounterCompareValue(base, EPWM_COUNTER_COMPARE_A, (uint16_t)PWM_CMPA_2);
        EPWM_setPhaseShift(base, 0U);
        EPWM_disablePhaseShiftLoad(base);
        EPWM_setTimeBaseCounter(base, 0U);
        EPWM_setSyncInPulseSource(base, EPWM_SYNC_IN_PULSE_SRC_SYNCOUT_EPWM1);

        set_phase(base, PHI);

    }

    else if(base == myEPWM3_BASE)
    {
        get_pwm_clock_from_freq(base , &PWM_TBPRD_1 , &PWM_TBPRD_2 , &PWM_TBPRD_3 , &PWM_CMPA_1 , &PWM_CMPA_2 , &PWM_CMPA_3 , &PWM_PARAM_PRESCALER , &PWM_PARAM_HIGHSPEEDPRESCALER, &TBCLK);

        // Parameters
        EPWM_setTimeBasePeriod(base, (uint16_t)PWM_TBPRD_3);
        EPWM_setCounterCompareValue(base, EPWM_COUNTER_COMPARE_A, (uint16_t)PWM_CMPA_3);

        EPWM_setPhaseShift(base, 0U);
        EPWM_disablePhaseShiftLoad(base);
        EPWM_setTimeBaseCounter(base, 0U);

        EPWM_setSyncInPulseSource(base, EPWM_SYNC_IN_PULSE_SRC_SYNCOUT_EPWM1);

        set_phase(base, PHI);

    }

    //EPWM_setTimeBaseCounter(base, 0U);
    EPWM_setTimeBaseCounterMode(base, EPWM_COUNTER_MODE_UP_DOWN);

    EPWM_setClockPrescaler(base, PWM_PARAM_PRESCALER, PWM_PARAM_HIGHSPEEDPRESCALER);

    // Set up shadowing
    EPWM_setCounterCompareShadowLoadMode(base, EPWM_COUNTER_COMPARE_A, EPWM_COMP_LOAD_ON_CNTR_ZERO);

    // Set actions
    EPWM_setActionQualifierAction(base, EPWM_AQ_OUTPUT_A, EPWM_AQ_OUTPUT_HIGH, EPWM_AQ_OUTPUT_ON_TIMEBASE_UP_CMPA);
    EPWM_setActionQualifierAction(base, EPWM_AQ_OUTPUT_A, EPWM_AQ_OUTPUT_LOW, EPWM_AQ_OUTPUT_ON_TIMEBASE_DOWN_CMPA);
    EPWM_setActionQualifierAction(base, EPWM_AQ_OUTPUT_B, EPWM_AQ_OUTPUT_HIGH, EPWM_AQ_OUTPUT_ON_TIMEBASE_UP_CMPA);
    EPWM_setActionQualifierAction(base, EPWM_AQ_OUTPUT_B, EPWM_AQ_OUTPUT_LOW, EPWM_AQ_OUTPUT_ON_TIMEBASE_DOWN_CMPA);

    // Trip zone
    // Configure ePWM1x to output low on TZx TRIP
    EPWM_setTripZoneAction(base, EPWM_TZ_ACTION_EVENT_TZA, EPWM_TZ_ACTION_LOW);
    EPWM_setTripZoneAction(base, EPWM_TZ_ACTION_EVENT_TZB, EPWM_TZ_ACTION_LOW);
    // Trigger event when DCBH is high
    EPWM_setTripZoneDigitalCompareEventCondition(base, EPWM_TZ_DC_OUTPUT_B1, EPWM_TZ_EVENT_DCXH_HIGH);
    // Configure DCBH to use TRIP4 as an input
    EPWM_enableDigitalCompareTripCombinationInput(base, EPWM_DC_COMBINATIONAL_TRIPIN4, EPWM_DC_TYPE_DCBH);
    // Enable DCB as OST
    EPWM_enableTripZoneSignals(base, EPWM_TZ_SIGNAL_DCBEVT1);
    // Configure the DCB path to be unfiltered and asynchronous
    EPWM_setDigitalCompareEventSource(base, EPWM_DC_MODULE_B, EPWM_DC_EVENT_1, EPWM_DC_EVENT_SOURCE_ORIG_SIGNAL);

    // Clear trip flags
    EPWM_clearTripZoneFlag(base, EPWM_TZ_INTERRUPT | EPWM_TZ_FLAG_OST);

    // Calculate delays
    get_delays_FED_RED(myEPWM1_BASE, &TBCLK);
    get_delays_FED_RED(myEPWM2_BASE, &TBCLK);
    get_delays_FED_RED(myEPWM3_BASE, &TBCLK);
}

您好、如果您使用向上/向下计数模式、则 PWM 周期将是配置的周期值的两倍。 因此、您需要相应地调整相移。
请注意、您还可以在相位同步期间设置计数器方向(使用 PHSDIR 位)。
因此、对于需要240deg 的相位、您必须使用 PHSDIR 反转方向。

你好 ，苏布拉赫曼尼亚 ，

感谢您的回复。 如果我理解正确，我们必须反转方向，因为 TBPHS 的值将超过最大 TBPRD ? 是否可以通过 driverlib 函数来反转方向？ 还是仅按位字段？

谢谢  

Damien

您好！

我找不到您的函数、但找到了该函数"ePWM_setCountModeAfterSync (myEPWM3_base、ePWM_COUNT_MODE_UP_After_SYNC)"。 当我希望 ePWM2°180°、而在 ePWM3上自然相位> 180°时、它不起作用

您能不能向我解释一下、在向上 和向下计数模式下、如何在 EPWM2和 EPWM3上实现更大的相位？

谢谢

Damien

你好  ，苏布拉赫曼尼亚 ，

很抱歉、我迟到了响应、最后我将 TBCTR 寄存器设置为向上计数模式、因为它在同步后不能在计数模式下工作。

我继续进行我的项目、稍后我将回到这个问题。

谢谢！

Damien