Upgrading Winbond W25N02KV to Winbond W25N02JV

Let's say you've designed a product around a Winbond W25N02KV 2 Gbit 3.3 V QSPI NAND flash, then your power delivery network changed and you decided to migrate to Winbond W25N02JW 2 Gbit 1.8 V QSPI NAND flash. Sounds easy, right?

Here's the storage layout of W25N02KV 3.3 V NAND flash series:

Per page, it has four 512-byte main data sectors, four non-ECC-protected 2-byte "User Data II" areas, and four ECC-protected 12-byte "User Data I" areas. This makes a total of 8 bytes of non-ECC-protected spare bytes, and a total of 48 ECC-protected spare bytes. There is also a parity area of four 16-byte areas that for most intents and purposes can be considered reserved.

Now let's look at its sister W25N02JW 1.8 V NAND flash series:

Per page, it has four 512-byte main data sectors, four non-ECC-protected 6-byte "User Data II" areas, and four ECC-protected 4-byte "User Data I" areas. This makes a total of 24 bytes of non-ECC-protected spare bytes, and a total of 16 ECC-protected spare bytes. There is no parity area any more, and out of 12 bytes per spare area that were ECC-protected on W25N02KV, 8 bytes are either non-ECC-protected or not user-writable any more.

Hope you didn't wish to store anything important there.