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Nand Flash driver model (FAL/FMD vs. MDD/PDD) concerning power loss RRS feed

  • General discussion

  • Hi.

    I am working on a NandFlash driver that uses the
    FAL/FMD model under Windows CE 6.0 R3. I have read different stories about
    problems with this model concerning power loss during file writes, but also
    about the new MDD/PDD model. My question: is the new MDD/PDD model more
    reliable than the old FAL/MDA model concerning power loss?

    I have made some tests to see what happens if the FMD
    layer return false when trying to read some sectors during startup and in worst
    case it will result in that the driver is unloaded again if certain sectors cannot
    be read.

    Does anyone have experience with both types of drivers and can say that it is
    worth spending the time to convert from the old FMD model to the new MDD/PDD
    model?

    Thanks for any comment.

    Best regards

    Frank.



    StrongIt - Frank Knudsen



    Tuesday, August 4, 2015 9:20 AM

All replies

  • Hi IoTGirl.

    Yes I have looked at that thread earlier, but thanks for the hint :). I have decided not to converting the driver because the information in the flash is structured differently and I need a solution that can be updated remotely and in a safe manner.

    Best regards

    Frank.


    StrongIt - Frank Knudsen

    Tuesday, September 8, 2015 9:14 AM
  • Both FAL-FMD and MDD-PDD model cover power loss case, in general. MDD-PDD model has better startup performance compared to FAL-FMD model. Also, the model to go for to cover power loss scenario depends on the NAND chip being used. FAL-FMD model uses Chip's "Partial Programming" capability to maintain information to cover power cut scenario, whereas MDD-PDD model do not use partial page programming concept. The reason being, FAL-FMD model was designed for SLC flash chips (which supports partial page programming), whereas MDD-PDD model is designed for MLC flash chip (which generally do not support partial page programming).

    Regards,

    Pranjal



    -Pranjal

    Saturday, September 26, 2015 3:39 PM