Question, i.MX25 BT_SPARE_SIZ setting

[Aemj]

Dear team,

I would like to ask about BT_SPARE_SIZ setting of i.MX25.

On my customer’s i.MX25 board, NAND-flash which has page-size of 512Byte is used for Boot storage.

i.MX25 does not boot-up when they set BT_SPARE_SIZ to 218B.

And when they set BT_SPARE_SIZ to 128B, then i.MX25 can boot-up.

Is setting BT_SPARE_SIZ reasonable for 512B pagesize NAND?

Could you show me what BT_SPARE_SIZ should be set to for 512b pagesize NAND?

And please let me know BT_SPARE_SIZ setting for 2KB NAND as well.

Thanks,

Miyamoto

[Yuri · Accepted solution]

  Please refer to Table 3 (Fuse Descriptions) of the app note AN3684, regarding

using the spare size parameter :

BT_SPARE_SIZE - Specifies the size of spare bytes for 4 Kbyte page size NAND

Flash devices.

Note: 512 byte page devices have 16 bytes spare area size,

2 Kbyte page devices have 64 bytes spare area size.

Note: Assumes that the large spare area devices (218 byte) use 8-bit ECC.

Otherwise, 4-bit ECC.

< http://cache.freescale.com/files/dsp/doc/app_note/AN3684.pdf >

Have a great day,
Yuri

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[Aemj]

Dear Yuri,

Thanks for your reply.

Can I understand that BT_SPARE_SIZE must be 0(128B) for 512B and 2KB pagesize NAND?

Best Regards,

Miyamoto

[Yuri]

Correct - "BT_SPARE_SIZE must be 0(128B) for 512B and 2KB pagesize NAND".

~Yuri.