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Compiler/TMS570LS3137: Bit error rate FlexRay TMS570LS337

user4769780
Intellectual 260 points
Part Number: TMS570LS3137

Tool/software: TI C/C++ Compiler

HELLO ,

My FlexRay Bus driver chip is TJA1080ATS,and use twisted pair  to communication,but my node Bit error rate is 1e-7，can you give me about FlexRAY Bit error rate data。I think is a normal error

  • 0
    TI__Guru 59540 points
    Hello User,

    I believe this is not a device level issue. It is a system level concern which should be handled via associated board and network level efforts.

    If you are using twisted pair, how long is the cabling? What is the bit rate/baud rate you are using? Is the cabling shielded? Do you have correct terminators?

    If you slow to a slower bit rate do the bit errors decrease? If you shorten the cable does it reduce?

    This may also be a timing optimization issue. i.e., how well have you aligned the bit rates between different nodes on the network. If there are tolerance issues this could contribute.

    I will also forward this to our FlexRay expert so he can add additional measures to either reduce line noise or improve message reliability in general.
  • 0 in reply to Chuck Davenport
    Intellectual 260 points

    This is my signal to GND ,can you think the signal is not clean？and my system communication Twisted pair all is about 5 Meters.

  • 0 in reply to Chuck Davenport
    Intellectual 260 points
    Thanks,In addition,I want to know which register can report the data link layer CRC error ,because i want to know the Bottom chip error , I just record in my Application layer code
  • 0 in reply to user4769780
    TI__Guru**** 193086 points

    Hello,

    The CRC of the received data is in Read Header Section Register.

  • 0 in reply to QJ Wang
    Intellectual 260 points
    And I want to know if the receive buffer head CRC or tail CRC error , the CC will discard the frame ,but the NDAT register about this buffer will set or not ?or which register can show this frame is a broken frame?
  • 0 in reply to user4769780
    TI__Guru**** 193086 points
    Hello,

    The CC transfers payload data of valid received messages from the shift registers to the receive buffer with the matching filter configuration.
    A receive buffer stores all frame elements except the frame CRC.

    The frame CRC calculation is done inside the CC before transmission or after reception of a frame. When a CC receives a frame it shall perform the frame CRC computations based on the header and payload field values received and check the computed value against the frame CRC value received in the frame. if the calculated and received values doesn't match, the CRC check fails. But there is no register to show the CRC error.