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TDA4VEN-Q1: SPI rx fifo overflow problem.

haijun
Intellectual 575 points

Part Number: TDA4VEN-Q1

I am developping on TDA4VEN using rtos sdk 11.01. 

We have 2 TDA4VEN on our custom board connected via SPI. I am developing full-duplex communication between them.

Currently, I am facing an issue on spi slave side: MCSPI_transfer returns ok but the trasaction status is MCSPI_TRANSFER_CANCELLED. After checking further, I found that this is due to an RX FIFO OVERFLOW on slave side. 

So I would like to know under which conditions would an RX FIFO OVERFLOW occurs? and what is the recommended way to avoid it?

For reference, I have attached my SPI syscfg settings for both slave and master:

image.png

image.png

and the rx fifo overflow is from this code branch:

image.png

  • 0
    TI__Guru 62936 points

    Hello,

    RX FIFO overflow in MCSPI slave mode occurs when data arrives faster than it can read it . The master sends data while the slave hasn't consumed previous data from the FIFO and RX FIFO is full and new data arrives .If using interrupt mode, the CPU takes too long to service the FIFO read interrupt and the slave application doesn't process received data quickly enough between transfers.

    what are your Rx fifo trigger levels ? keep it at minimum 8 or something.

    Are there any high priority events happening on slave other than SPI ?

    Regards

    Tarun Mukesh 

  • 0 in reply to Tarun Mukesh Puvvada
    Intellectual 575 points

    Rx Fifo trigger level is 16.

    interrupt priority is 4.

    I would like to know further:

    1. is priority number the smaller the number, the higher the priority? what is the recommended SPI priority?

    2. Would this problem be solved if I change it from interrupt mode to DMA mode?

  • +1 in reply to haijun
    TI__Guru 62936 points

    Hello,

    haijun said:
    is priority number the smaller the number, the higher the priority? what is the recommended SPI priority?

    Yes smaller the number higher the priority. You can go with the possible as lowest as possible. Rx FIFO trigger level you can change to 8.

    if these don't work out yet then you can also go with DMA Mode for faster operations

    Regards

    Tarun Mukesh

  • 0 in reply to Tarun Mukesh Puvvada
    Intellectual 575 points

    switched to DMA mode, and this problem disappears.

    thanks.