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6678 high capacity NAND Flash support

Jeff Brower73
Genius 3420 points

TI Experts-

Our board has a NAND Flash device with 8x the capacity of the one on the EVM 6678 board.  I've read through this thread:

  http://e2e.ti.com/support/dsp/c6000_multi-core_dsps/f/639/t/178889.aspx

and I think we may not be able to use our current device as its requires an ECC calculate rate of 4-bits up to 528 bytes, and the 6678 NAND controller supports 4-bits up to 512 bytes.  My questions:

1) As a temporary measure, until we change our board design, is it possible to configure our device with identical page size as the EVM, but define more spare bytes per page?  For example, in our case we would have 1600 bytes (out of 2112 total bytes per page) defined as spare / not used.  In platform library NAND driver definitions, we would correctly set pages per block, blocks per device, and we would maintain all ECC constants.

2) Since ECC structure / support seems to be the main obstacle, would you recommend using a NAND Flash device with internal ECC support and then disabling ECC in the 6678 NAND controller?  Is this possible?

3) Is there a high capacity NAND Flash device that you can recommend for new 6678 designs?

Thanks.

-Jeff
Signalogic

  • 0
    TI__Mastermind 42545 points

    Hi Jeff,

    The hardware ECC within the C6678 was based on the lower capacity NAND flash devices and doesn't support the higher capacity NAND devices with larger ECC requirements. These NAND flash devices can be used but the ECC calculation would have to be made in software instead of using the hardware in the EMIF16. Example code for a software ECC is included in the MCSDK release. If software ECC is included there isn't a limit to the size of the NAND used. We don't currently have any recommendation for higher capacity parts.

    Regards, Bill

  • 0 in reply to Bill Taboada
    Genius 3420 points

    Bill-


    I want to follow-up on this.  It appears that platform_lib for the EVM 6678 contains ECC support in software, is this accurate?  I ask because I tried modifying platform_lib ECC software for our Flash device (with 8x higher capacity) and no luck so far -- I think Flash reads may be working, but not Flash writes.

    Do you guys have an example for disabling ECC in the EMIF16 controller?

    Thanks.

    -Jeff