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stevenoonan's avatar
stevenoonan
Copper Contributor
Mar 04, 2021

LevelX with SDCard

I am looking at LevelX to use with an SD Card. I see that LevelX uses the 'spare' byes on each page.

 

It appears that the extra, say, 16 bytes on a 512 byte nominal page means there is actually 528 bytes per page. This accords with my experience with small NAND Serial Data Flash chips where I have direct access to 528 bytes per page.

 

I'm new to using SD Cards so I'm not too familiar with the spec. Are the extra bytes available to read/write? The SD Card I'm using reports 512 bytes per page. I cannot see or find any way to access the extra bytes. I'm using the i.MXRT 1064 with NXP's SDK (fsl_sd.c, fsl_sdmmc.c, etc.)

 

Or, is LevelX not advisable for SD Cards? I understand that at least some SD Cards have wear leveling built in, but I didn't think it was universal. Am I wrong in this assumption?

2 Replies

  • XiuwenCai's avatar
    XiuwenCai
    Copper Contributor
    Mar 11, 2021
    stevenoonan, LevelX is not designed for SD cards. LevelX does use the spare bytes in NAND flash, but there is no way to access the spare bytes in SD card.
    • stevenoonan's avatar
      stevenoonan
      Copper Contributor
      Mar 11, 2021

      XiuwenCai Okay, that is what I was suspecting, after making the post. Thank you for the clarification.

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