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TUSB4041I: Any register or error count for CRC error?

Sean Wang
Prodigy 30 points

Part Number: TUSB4041I

Hi Expert,

Is there any register or error counter built into TUSB4041I that can indicate if CRC or other errors have occurred in the downstream ports?

The downstream ports will receive video streams via NCM in our application and transmit them to a wireless router via the upstream port. Although we can use "ifconfig" to check for packet loss, we are wondering if we could distinguish whether the packet loss is caused by the network layer or the lower USB layer.

Thank you.

  • 0
    TI__Guru**** 154260 points

    Do you know what data format transfer for video streams? Isochronous  or bulk?

    Also can you send schematic for review?

    Best

    Brian

  • 0 in reply to Brian Zhou
    Prodigy 30 points

    No, I'm not sure about the format, and I'm checking internally. I learned that bulk transfer is the default format of NCM. Assuming we use bulk transfer, is there any log or error counter that can indicate if something is wrong in the USB layer?

    Regarding the schematics, Allan will help to provide them. But I believe you have already reviewed them.

    cc  

  • 0 in reply to Sean Wang
    TI__Guru**** 154260 points

    Hi Sean:

       for bulk transfer, it will guarantee to transfer all data but long latency.

       For  Isochronous  transfer, it will guarantee  enough bandwidth to transfer data, but not guarantee  all data get transferred.

      What is NCM?

    Regards

    Brian

       

  • 0 in reply to Brian Zhou
    Prodigy 30 points

    Hi Brian,

    We use bulk transfer. I understand it will guarantee to transfer all data. If there's a CRC error, the receiver will send NAK and the transmitter will re-send the data, right? I'm just wondering if there's any message regarding the CRC error I can get from TUSB4041 instead of our SOC receiver.

    NCM means Network Control Mode, a subclass of USB CDC.

  • 0 in reply to Sean Wang
    TI__Guru**** 154260 points

    HI Sean:

       There is no  register or status  bit for TUSB4041 to indicate data transfer successful or  with CRC error. 

    Sean Wang said:
    If there's a CRC error, the receiver will send NAK and the transmitter will re-send the data, right?

    this is correct.

        Do you see any issue for data transfer?

    Best

    Brian

  • 0 in reply to Brian Zhou
    Prodigy 30 points

    Thanks.

    Brian Zhou said:
    Do you see any issue for data transfer?

    No, I haven't received our EVT samples. Will let you know if there are any related issues.