TMS320F28P550SG: 互补HRPWM的Duty不完全一样

我使用syscfg配置了一个互补的HRPWM1，使用示波器发现这个互补的波形高电平时间并不一样，一个是476ns左右，另一个是454ns左右。请问原因是什么？以下是利用syscfg配置的DebugCode：
 HRPWM_enableGlobalLoad(LLC_A_BASE);    
    HRPWM_enableGlobalLoadOneShotMode(LLC_A_BASE);    
    HRPWM_setGlobalLoadOneShotLatch(LLC_A_BASE);    
    HRPWM_setEmulationMode(LLC_A_BASE, EPWM_EMULATION_FREE_RUN);    
    HRPWM_setClockPrescaler(LLC_A_BASE, EPWM_CLOCK_DIVIDER_1, EPWM_HSCLOCK_DIVIDER_1);    
    EPWM_setTimeBasePeriod(LLC_A_BASE, 75);    
    HRPWM_setTimeBaseCounter(LLC_A_BASE, 0);    
    HRPWM_setTimeBaseCounterMode(LLC_A_BASE, EPWM_COUNTER_MODE_UP_DOWN);    
    EPWM_disablePhaseShiftLoad(LLC_A_BASE);
    HRPWM_disablePhaseShiftLoad(LLC_A_BASE);    
    HRPWM_setPhaseShift(LLC_A_BASE, 0);    
    EPWM_setSyncInPulseSource(LLC_A_BASE, EPWM_SYNC_IN_PULSE_SRC_DISABLE);    
    EPWM_enableSyncOutPulseSource(LLC_A_BASE, EPWM_SYNC_OUT_PULSE_ON_CNTR_ZERO);    
    EPWM_setCounterCompareValue(LLC_A_BASE, EPWM_COUNTER_COMPARE_A, 37);    
    HRPWM_enableGlobalLoadRegisters(LLC_A_BASE, EPWM_GL_REGISTER_CMPA_CMPAHR);    
    HRPWM_setCounterCompareShadowLoadMode(LLC_A_BASE, EPWM_COUNTER_COMPARE_A, EPWM_COMP_LOAD_ON_CNTR_ZERO_PERIOD);    
    EPWM_setCounterCompareValue(LLC_A_BASE, EPWM_COUNTER_COMPARE_B, 37);    
    HRPWM_enableGlobalLoadRegisters(LLC_A_BASE, EPWM_GL_REGISTER_CMPB_CMPBHR);    
    HRPWM_setCounterCompareShadowLoadMode(LLC_A_BASE, EPWM_COUNTER_COMPARE_B, EPWM_COMP_LOAD_ON_CNTR_ZERO_PERIOD);    
    HRPWM_enableGlobalLoadRegisters(LLC_A_BASE, EPWM_GL_REGISTER_AQCTLA_AQCTLA2);    
    HRPWM_setActionQualifierAction(LLC_A_BASE, EPWM_AQ_OUTPUT_A, EPWM_AQ_OUTPUT_NO_CHANGE, EPWM_AQ_OUTPUT_ON_TIMEBASE_ZERO);    
    HRPWM_setActionQualifierAction(LLC_A_BASE, EPWM_AQ_OUTPUT_A, EPWM_AQ_OUTPUT_NO_CHANGE, EPWM_AQ_OUTPUT_ON_TIMEBASE_PERIOD);    
    HRPWM_setActionQualifierAction(LLC_A_BASE, EPWM_AQ_OUTPUT_A, EPWM_AQ_OUTPUT_HIGH, EPWM_AQ_OUTPUT_ON_TIMEBASE_UP_CMPA);    
    HRPWM_setActionQualifierAction(LLC_A_BASE, EPWM_AQ_OUTPUT_A, EPWM_AQ_OUTPUT_LOW, EPWM_AQ_OUTPUT_ON_TIMEBASE_DOWN_CMPA);    
    HRPWM_setActionQualifierAction(LLC_A_BASE, EPWM_AQ_OUTPUT_A, EPWM_AQ_OUTPUT_NO_CHANGE, EPWM_AQ_OUTPUT_ON_TIMEBASE_UP_CMPB);    
    HRPWM_setActionQualifierAction(LLC_A_BASE, EPWM_AQ_OUTPUT_A, EPWM_AQ_OUTPUT_NO_CHANGE, EPWM_AQ_OUTPUT_ON_TIMEBASE_DOWN_CMPB);    
    HRPWM_setActionQualifierAction(LLC_A_BASE, EPWM_AQ_OUTPUT_B, EPWM_AQ_OUTPUT_NO_CHANGE, EPWM_AQ_OUTPUT_ON_TIMEBASE_ZERO);    
    HRPWM_setActionQualifierAction(LLC_A_BASE, EPWM_AQ_OUTPUT_B, EPWM_AQ_OUTPUT_NO_CHANGE, EPWM_AQ_OUTPUT_ON_TIMEBASE_PERIOD);    
    HRPWM_setActionQualifierAction(LLC_A_BASE, EPWM_AQ_OUTPUT_B, EPWM_AQ_OUTPUT_NO_CHANGE, EPWM_AQ_OUTPUT_ON_TIMEBASE_UP_CMPA);    
    HRPWM_setActionQualifierAction(LLC_A_BASE, EPWM_AQ_OUTPUT_B, EPWM_AQ_OUTPUT_NO_CHANGE, EPWM_AQ_OUTPUT_ON_TIMEBASE_DOWN_CMPA);    
    HRPWM_setActionQualifierAction(LLC_A_BASE, EPWM_AQ_OUTPUT_B, EPWM_AQ_OUTPUT_NO_CHANGE, EPWM_AQ_OUTPUT_ON_TIMEBASE_UP_CMPB);    
    HRPWM_setActionQualifierAction(LLC_A_BASE, EPWM_AQ_OUTPUT_B, EPWM_AQ_OUTPUT_NO_CHANGE, EPWM_AQ_OUTPUT_ON_TIMEBASE_DOWN_CMPB);    
    HRPWM_setDeadBandDelayPolarity(LLC_A_BASE, EPWM_DB_FED, EPWM_DB_POLARITY_ACTIVE_LOW);    
    HRPWM_setDeadBandDelayMode(LLC_A_BASE, EPWM_DB_RED, true);    
    HRPWM_setRisingEdgeDelayCountShadowLoadMode(LLC_A_BASE, EPWM_RED_LOAD_ON_CNTR_ZERO);    
    HRPWM_setRisingEdgeDelayCount(LLC_A_BASE, 10);    
    HRPWM_setDeadBandDelayMode(LLC_A_BASE, EPWM_DB_FED, true);    
    HRPWM_setFallingEdgeDeadBandDelayInput(LLC_A_BASE, EPWM_FED_LOAD_ON_CNTR_ZERO);    
    HRPWM_setFallingEdgeDelayCount(LLC_A_BASE, 10);    
    HRPWM_setDeadBandCounterClock(LLC_A_BASE, EPWM_DB_COUNTER_CLOCK_HALF_CYCLE);    
    HRPWM_enableAutoConversion(LLC_A_BASE);    
    HRPWM_setMEPEdgeSelect(LLC_A_BASE, HRPWM_CHANNEL_A, HRPWM_MEP_CTRL_RISING_AND_FALLING_EDGE);    
    HRPWM_setCounterCompareShadowLoadEvent(LLC_A_BASE, HRPWM_CHANNEL_A, HRPWM_LOAD_ON_CNTR_ZERO_PERIOD);    
    HRPWM_setMEPEdgeSelect(LLC_A_BASE, HRPWM_CHANNEL_B, HRPWM_MEP_CTRL_RISING_AND_FALLING_EDGE);    
    HRPWM_setCounterCompareShadowLoadEvent(LLC_A_BASE, HRPWM_CHANNEL_B, HRPWM_LOAD_ON_CNTR_ZERO_PERIOD);    
    HRPWM_enablePeriodControl(LLC_A_BASE);    
    HRPWM_setHiResTimeBasePeriodOnly(LLC_A_BASE, 127);    
    HRPWM_setDeadbandMEPEdgeSelect(LLC_A_BASE, HRPWM_DB_MEP_CTRL_RED_FED);