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CCS/PGA411-Q1: PGA411-Q1 communication with TMS320F28335 via SPI

Part Number: PGA411-Q1

Tool/software: Code Composer Studio


I use DSP28335 communication with PGA411 via SPI , sending data correctly, but without receiving any data.

(1)Reference example TIDA-00796-LIGHT , thePGA411 will reset after SPI configuration, I don't have reset PGA411, is this step necessary?

(2)The other problem is

"The NCS pin is kept low when sending a 32-bit command. One byte is loaded to the SPI shift registers
and then sent to the slave device, which occurs 4 times to maintain the 32-bit time frame."

Does it need a delay(200ns) between one byte and another byte?

(3) When I single step debug, as soon as the data is sent, the FAULT pin isHi-Z state. It means there is a fault.

Can you help me?

Best Regards,

Volinca Na

  • I am sorry to say that I made a low-level error,SDO and SDI were connected reversely.
    The first question " thePGA411 will reset after SPI configuration" is not necessary.
  • Volinca,

    1.) I'm glad that you were able to debug the first question yourself! That is an easy mistake to make.

    2.) You have to wait 200ns between consecutive frames (when NCS goes from low to high and then low again to start the next frame). The four bytes for one SPI frame can happen as quickly as possible. It can be implemented so that they are all back-to-back.

    3.) If a fault is occurring, the first thing to do is read the fault status registers to determine which fault is being set. If you are stepping through the code, it is probably the SPI_ERR flag. You can check the SPI error code by reading the SPI_STAT bits. Also, sometimes during development and debugging, it is helpful to ignore the faults, which can be done by keeping FAULTRES low. If you need help debugging why certain faults are occurring, please check the troubleshooting guide:

    Please continue to reach out to us if you have other questions.