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TMS320C6657: 4bit ECC nand error

Genius 13655 points
Part Number: TMS320C6657

Hello Champs,

6657 EMIF's ce0 connect to nandflash (MT29F8G08ABBCAH4), details as shown below, total (4K + 224) byte per page. 

Reference evmc665x nand example, select the EMIF 4bit ECC as ce0, read and write every 512 bytes, read and write a page from 4 times to 8 times.

It was found that when the first data read nandflash error occurred after the power failure was restarted, the software error correction read the NANDFSR register to make a judgment, it goes to the over 4 bit error branch, which is case 1 in the figure below.

However, when judging what data is read and what is written, only a 1bit error is found, but the error in the hardware judgment causes the error to fail. What is the cause of this?



Thanks
Regards
Shine

  • Hello, The engineer (Sankari) responsible is currently out of office for next few weeks.

    Please expect 2 week delay in response.

    Thanks.

  • Shine,

    Just to understand your problem better, please answer the questions below.

    1. Are you testing 4 bit NAND ECC errors ? or while doing data transfer, you are experiencing this error?

    2. Atleast for one time, are you able to transfer data to nand memory without any errors ? 

    3. Have you tried the sample NAND examples of processor SDK 6.3 with the TI-C6657 EVM ?

    Because, this will give some good understanding before we move on to the custom board ( i.e., own board)

    4. Please mention the name of the example code and version of the SDK you use for this test.

    Regards

    Shankari G 

  • Hi Shankari G,

    Sorry for the late response.

    Below is the reply from customer.

    1.While doing data transfer, I expect to encounter less than 4 bit data error to check whether EMIF Ecc Correct works. When the first 1 bit error comes, it seems like EMIF Ecc Correct doesn't work. However, the other times, EMIF Ecc Correct works.

    2.Yes, Most of the time the test is correct.

    About Question 3 and 4, because of the NAND difference between TI-C6657 EVM and our board, we reprogram based on SDK(c665x-evm-06.03.00.106-Windows-x86-Install) and routine(evmc665x_nand.h).



    Thanks
    Regards
    Shine

  • Shine,

    Let me look into the first one.

    Regarding my questions on 3 and 4, I understand, you re-program for your custom board.

    My question is " Do you have TI-C6657 EVM ? 

    Did you happen to run the sample NAND examples of processor SDK 6.3 on Ti-C6657 EVM ? 

    Is it possible to reproduce the same data transfer test on the TI EVM and reproduce the same error ?

    Because, this will narrow down whether it is a NAND flash memory issue which you use in your custom board......

    Regards

    Shankari G