Blank pages/sectors ECC on Winbond W25N01GV?

[troed]

Hi,

I think I'm missing a setting in the software, either due to not finding it or it not being there When I flash the NAND with the chip's built-in ECC active FlashCat also writes the empty pages. The problem is that the ECC area will then be set to all zeroes for those sectors, while the chip "originally" has all 0xff throughout such sectors including the ECC.

This results in ECC errors when software later reads an empty sector. I've seen a technical note from Winbond that, unless I misunderstand, recommends either not programming these pages at all or turning of the built-in ECC when doing them: https://www.techdesign.com/market/w...k-with-winbond-serial-nand-flash-build-in-ecc

Any tips on how to sort this out?

regards,
Troed

 

[Pantheon]

So if I understand you correctly, you are writing data into the device, and in your existing data, you are NOT writing into OOB, but that data is page aligned and if the entire page is blank (0xFF), you DONT want to write it, as it will also update the OOB for that page. Or, does your data contain ALL data (main+OOB), but with the area that ECC goes is blank, and pages that are to be skipped will have both Main and OOB blank (0xFF)?

 

[troed]

So if I understand you correctly, you are writing data into the device, and in your existing data, you are NOT writing into OOB, but that data is page aligned and if the entire page is blank (0xFF), you DONT want to write it, as it will also update the OOB for that page. Or, does your data contain ALL data (main+OOB), but with the area that ECC goes is blank, and pages that are to be skipped will have both Main and OOB blank (0xFF)?

The first case. A completely blank page should apparently be written with the internal ECC off otherwise the chip will internally update the ECC information in the OOB. Of course, the simpler solution is to not write blank pages which will have the same result.

I've seen in my XGecu software that "skip blank" exists as an option. I would like to use the Flashcat though since I've been successful in hooking that up in-circuit while I haven't been able to get the XGecu working the same way.