Why data shifted in but no INT triggered for FlexIO

[kenmux]

Based on code of flexio_uart, I try to do some waveform simulation on the board IMXRT050-EVKB.

I use 1 shifter and 1 timer for sending, and the baud rate is 125000, and sending 1 bit each time.

The config code as below:

/* Do hardware configuration. */
/* 1. Configure the shifter 0 for tx. */
shifterConfig.timerSelect = base->timerIndex[0];
shifterConfig.timerPolarity = kFLEXIO_ShifterTimerPolarityOnPositive;
shifterConfig.pinConfig = kFLEXIO_PinConfigOutput;
shifterConfig.pinSelect = base->TxPinIndex;
shifterConfig.pinPolarity = kFLEXIO_PinActiveLow;
shifterConfig.shifterMode = kFLEXIO_ShifterModeTransmit;
shifterConfig.inputSource = kFLEXIO_ShifterInputFromPin;
shifterConfig.shifterStop = kFLEXIO_ShifterStopBitDisable;
shifterConfig.shifterStart = kFLEXIO_ShifterStartBitDisabledLoadDataOnEnable;

FLEXIO_SetShifterConfig(base->flexioBase, base->shifterIndex[0], &shifterConfig);

/* 2. Configure the timer 0 for tx. */
timerConfig.triggerSelect = FLEXIO_TIMER_TRIGGER_SEL_SHIFTnSTAT(base->shifterIndex[0]);
timerConfig.triggerPolarity = kFLEXIO_TimerTriggerPolarityActiveLow;
timerConfig.triggerSource = kFLEXIO_TimerTriggerSourceInternal;
timerConfig.pinConfig = kFLEXIO_PinConfigOutput; //kFLEXIO_PinConfigOutputDisabled;
timerConfig.pinSelect = base->TxPinIndex +2; //base->TxPinIndex;
timerConfig.pinPolarity = kFLEXIO_PinActiveHigh;
timerConfig.timerMode = kFLEXIO_TimerModeDual8BitBaudBit;
timerConfig.timerOutput = kFLEXIO_TimerOutputOneNotAffectedByReset;
timerConfig.timerDecrement = kFLEXIO_TimerDecSrcOnFlexIOClockShiftTimerOutput;
timerConfig.timerReset = kFLEXIO_TimerResetNever;
timerConfig.timerDisable = kFLEXIO_TimerDisableOnTimerCompare;
timerConfig.timerEnable = kFLEXIO_TimerEnableOnTriggerHigh;
timerConfig.timerStop = kFLEXIO_TimerStopBitDisabled;
timerConfig.timerStart = kFLEXIO_TimerStartBitDisabled;
timerConfig.timerCompare = timerCmp;

FLEXIO_SetTimerConfig(base->flexioBase, base->timerIndex[0], &timerConfig);‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

For receive, I use 1 shiftier and 1 timer too, and the baud rate is the same, and also receiving 1 bit each time.

The config code as below:

    /* 3. Configure the shifter 1 for rx. */
    shifterConfig.timerSelect   = base->timerIndex[1];
    shifterConfig.timerPolarity = kFLEXIO_ShifterTimerPolarityOnNegitive;
    shifterConfig.pinConfig     = kFLEXIO_PinConfigOutputDisabled;
    shifterConfig.pinSelect     = base->RxPinIndex;
    shifterConfig.pinPolarity   = kFLEXIO_PinActiveHigh;
    shifterConfig.shifterMode   = kFLEXIO_ShifterModeReceive;
    shifterConfig.inputSource   = kFLEXIO_ShifterInputFromPin;
    shifterConfig.shifterStop   = kFLEXIO_ShifterStopBitDisable;
    shifterConfig.shifterStart  = kFLEXIO_ShifterStartBitDisabledLoadDataOnEnable;

    FLEXIO_SetShifterConfig(base->flexioBase, base->shifterIndex[1], &shifterConfig);

    /* 4. Configure the timer 1 for rx. */
    timerConfig.triggerSelect   = FLEXIO_TIMER_TRIGGER_SEL_PININPUT(base->RxPinIndex);
    timerConfig.triggerPolarity = kFLEXIO_TimerTriggerPolarityActiveHigh;
    timerConfig.triggerSource   = kFLEXIO_TimerTriggerSourceExternal;
    timerConfig.pinConfig       = kFLEXIO_PinConfigOutputDisabled;
    timerConfig.pinSelect       = base->RxPinIndex;
    timerConfig.pinPolarity     = kFLEXIO_PinActiveHigh;
    timerConfig.timerMode       = kFLEXIO_TimerModeDisabled;
    timerConfig.timerOutput     = kFLEXIO_TimerOutputOneNotAffectedByReset;
    timerConfig.timerDecrement  = kFLEXIO_TimerDecSrcOnFlexIOClockShiftTimerOutput;
    timerConfig.timerReset      = kFLEXIO_TimerResetNever;
    timerConfig.timerEnable     = kFLEXIO_TimerEnableOnPinRisingEdge;
    timerConfig.timerDisable    = kFLEXIO_TimerDisableNever;
    timerConfig.timerStop       = kFLEXIO_TimerStopBitDisabled;
    timerConfig.timerStart      = kFLEXIO_TimerStartBitDisabled;
    timerConfig.timerCompare    = timerCmp;

    FLEXIO_SetTimerConfig(base->flexioBase, base->timerIndex[1], &timerConfig);‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

The code for sending:

            /* Enable RX interrupt. */
            FLEXIO_J1850_EnableInterrupts(base, kFLEXIO_J1850_RxDataRegFullInterruptEnable);

            /* Enable Rx timer */
            FLEXIO_J1850_SetTimerMode(base, base->timerIndex[1], kFLEXIO_TimerModeDual8BitBaudBit);

            /* Enable transmiter interrupt. */
            FLEXIO_J1850_EnableInterrupts(base, kFLEXIO_J1850_TxDataRegEmptyInterruptEnable);‍‍‍‍‍‍‍‍

Then I do some echo test, but the result is NG. Refer to the attached.

(Sorry I cannot insert the images)

Some description:

1->TX

2->TX Timer Output

3->RX

4->GPIO Triggered in RX_INT

It seems the first 2 RX_INTs are missing.

For I can find the data in the shifter buffer.

Reason is unknown. Any ideas?

Thanks in advance!

[kenmux]

Sorry for the stupid question. This delay is fine.

For only when all data written to SHIFTBUF should there be an INT.

That's it.

[Sabina_Bruce]

Hello Kenmux,

Hope you are doing well.

From my understanding you are trying to create a waveform. Could you please try to use the pwm example. Could you please confirm if the results or the same or you are attempting something different?

Best Regards,

Sabina

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