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  • eMMC CSD Register ECC field

    From Buzz McCool@21:1/5 to All on Tue Apr 12 17:54:16 2022
    Anyone here knowledgeable about eMMC memory?

    I have a high reliability application where there is concern about
    memory corruption. What would happen if I changed the ECC field in the
    eMMC's Card Specific Data (CSD) register from the default no ECC to the optional BCH(542,512) encoding? Would I still be able to write/read new
    values to the eMMC normally with the eMMC internally protecting the
    contents with BCH ECC at the cost of reduced memory capacity, or would a special driver on the host be needed to encode/decode ECC reads/writes?

    I've asked around and haven't found a definitive answer so far. Let me
    know if you can help ... Buzz

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  • From Boudewijn Dijkstra@21:1/5 to Buzz McCool on Thu Jun 9 16:06:40 2022
    Buzz McCool schreef:
    Anyone here knowledgeable about eMMC memory?

    I have a high reliability application where there is concern about
    memory corruption. What would happen if I changed the ECC field in the
    eMMC's Card Specific Data (CSD) register from the default no ECC to the optional BCH(542,512) encoding? Would I still be able to write/read new values to the eMMC normally with the eMMC internally protecting the
    contents with BCH ECC at the cost of reduced memory capacity, or would a special driver on the host be needed to encode/decode ECC reads/writes?

    I've asked around and haven't found a definitive answer so far. Let me
    know if you can help ... Buzz

    Asked around? Why not consult the standard? From there I gather that
    eMMC devices may implement internal ECC (that is why the DEVICE_ECC_
    FAILED status exists) and that the "ECC" configuration field may be used
    for external ECC. If nonzero, your driver should handle the ECC encoding/decoding.


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