MSPM0G1106: SPI Read and Write

Your previous code has

>  SPI_ClearRxFIFO(SPI0);

to clear out the Rx byte you got back from sending the command. I don't see an exact equivalent, but since you know there's only one byte in the Rx FIFO you could use:

> (void)DL_SPI_receiveData8(SPI_0_INST); // Read and throw away

(void)DL_SPI_receiveData8(SPI_0_INST); // Read and throw I am trying to use this code, but there is no data retrieval, what code should I write?

Try to add :

while (DL_SPI_isRXFIFOEmpty(spi));

before SPI_Received_data= DL_SPI_receiveData8(SPI_0_INST);

uint8_t DUMMY=0x00;


unsigned char MFRC522_SPIreceive(uint8_t address_rcv)
{

    uint8_t SPI_receive_address = (((address_rcv << 1) & 0x7E) | 0x80);

   

    DL_SPI_transmitData8(SPI_0_INST, SPI_receive_address);

    while (DL_SPI_isBusy(SPI_0_INST));

    while (DL_SPI_isRXFIFOEmpty(SPI_0_INST));




    DL_SPI_transmitData8(SPI_0_INST, DUMMY);

    while (DL_SPI_isBusy(SPI_0_INST));

    SPI_Received_data= DL_SPI_receiveData8(SPI_0_INST);




    return SPI_Received_data;
}






int main(void)
{
    SYSCFG_DL_init();

    while (1) {

       MFRC522_SPIreceive(0x11);
        delay_cycles(500000);

    }
}

I can see 0x3f in other MCU, but I can't see it in Texas, it doesn't appear in the debug.

I'm not sure I understand what you mean by "no data retrieval".

That line should be inserted just before the second call to DL_SPI_transmitData8 (just as it was in your original code).

In the SPI, every Tx byte gets back an Rx byte. Even if you're not interested in the Rx byte, you need to deal with it, usually by reading it and throwing it away.

I don't understand why I don't have it. I'm constantly reading 0xff from the buffer. I checked my hardware. Did I do the SPI configuration wrong? Could you check it?

If you're getting back 0xFF rather than the 0x00 shown in your analyzer trace, I suppose that means you have leftover bytes in the (Rx) FIFO from some earlier transactions. If so, you should do a full empty of the FIFO with something like:

> while (!DL_SPI_isRXFIFOEmpty(SPI_0_INST)) {(void)DL_SPI_receiveData8(SPI_0_INST);} // Empty the Rx FIFO

The value I need to read from FIFO is 0x3f, but I always read 0xff. I will implement what you said tomorrow and let you know the situation.

We are reading, but we need to read the mathematical process as follows. Why might it be?

uint8_t SPI_receive_address = (((address_rcv << 1) & 0x7E) | 0x80);



    DL_SPI_transmitData8(SPI_0_INST, SPI_receive_address);

    while (DL_SPI_isBusy(SPI_0_INST));


    while (DL_SPI_isRXFIFOEmpty(SPI_0_INST));

    DL_SPI_transmitData8(SPI_0_INST, DUMMY);

    while (DL_SPI_isBusy(SPI_0_INST));



    while (!DL_SPI_isRXFIFOEmpty(SPI_0_INST)) {
        SPI_Received_data= DL_SPI_receiveData8(SPI_0_INST);
}
    SPI_Received_data=0xff-SPI_Received_data;<-------------

That wasn't exactly what I was suggesting, but it seems that it should work.

It almost sounds like you've somehow set "invert" in your Iomux configuration. In sysconfig, what does it show under "Communications->SPI->Pin Configuration->SPI POCI [Enable pin configuration checkbox]->Digital IOMUX Features->Invert"?

Hello, I think we have come a long way, but I am telling you my problem right away because it is not working exactly as desired. I solved the problem of reading data correctly, but some of the data I read in the FIFO is old data. Let me explain it like this: The field I read in the attachment I sent is not the same as the field I read in the debug. I think it's a data read slip, I can't be sure that the FIFO is emptied and I can't empty it manually. By the way TxControlReg= 0x14 . Do you have new recomandation ?

...

unsigned char MFRC522_SPIreceive(unsigned char address_rcv)
{
    // Okuma işlemi için adres
    uint8_t SPI_receive_address = (((address_rcv << 1) & 0x7E) | 0x80);

    MFRC_NSS_OFF;


    DL_SPI_transmitData8(SPI_0_INST, SPI_receive_address);

    while (DL_SPI_isBusy(SPI_0_INST));


    //while (!DL_SPI_isRXFIFOEmpty(SPI_0_INST));

    DL_SPI_transmitData8(SPI_0_INST, DUMMY);
    while (DL_SPI_isBusy(SPI_0_INST));


    while (!DL_SPI_isRXFIFOEmpty(SPI_0_INST)) {
    SPI_Received_data= DL_SPI_receiveData8(SPI_0_INST);
}
    //SPI_Received_data=0xff-SPI_Received_data;


MFRC_NSS_ON;


delay_cycles(200);



    return SPI_Received_data;
}

You can read SPI data to empty fifo

I'm glad you got it working.