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weid's avatar
weid
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6 years ago

CRC_ERROR of Cyclone IV E device

Hi, My design use Cyclone IV E device with Nios as processer, the board be used on power plant as control board. Until now, we have near 10000 pcs board used on power plant. From February to now, ...
ShafiqY_Intel's avatar
ShafiqY_Intel
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6 years ago

Hi Weidong,

1- Based on my observation, 5 out of 10000 pcs (0.05%) is consider normal.

2- CRC only check FPGA configuration bits, which mean only 30% of your CRAM is checked.

3- I have not face the problem where CRC_ERROR will active sometimes mistakenly. CRC_ERROR only active if CRC valus do not match with pre-computed CRC.

  • When a data frame is loaded into the FPGA during configuration, the pre-computed CRC value shifts into the CRC circuitry in the FPGA. At the same time, the CRC engine in the FPGA computes the CRC value for the data frame received, and stores the CRC value into the configuration RAM (CRAM). The pre-computed CRC value is compared against the CRC value computed by the CRC engine. If the CRC values do not match, nSTATUS is set low to flag a configuration error.

4- If CRAM bit fault, your logic generate and design will not behave as you expected (fault result).

Thanks.😉

  • weid's avatar
    weid
    Icon for New Contributor rankNew Contributor
    6 years ago

    hi, very thanks for your reply.

    Could i check one item with you again about your point 3.

    You means that "i have face" or "i have not face" the problem CRC_ERROR will active sometimes mistakenly? do you know that whether clyone 4 e device have this case(no CRAM fault but CRC_ERROE active) also.

    • ShafiqY_Intel's avatar
      ShafiqY_Intel
      Icon for Frequent Contributor rankFrequent Contributor
      6 years ago

      I'm sorry for typo. I means "I have not face".