Skip to contentSkip to conversation

NAND page programm

DISCUSSION Artem B. Bityuckiy 2 participants 4 messages Sep 12, 2004 – Sep 13, 2004 Memory technology devices (MTD)

lore
Share & tools
lore
#0 lore raw

Hello guys.

As I understand the NAND_CMD_READ0 command is the "read whole page" command. What doed the NAND_CMD_READ1 command exactly mean? Is there some fixed semantic? (see linux/mtd/nand.h)

Thanks.

Signature · 3 lines
Best Regards,
Artem B. Bityuckiy,
St.-Petersburg, Russia.
#1 lore raw
Quoted 5 lines · Artem B. Bityuckiy

Hello guys.

As I understand the NAND_CMD_READ0 command is the "read whole page" command. What doed the NAND_CMD_READ1 command exactly mean? Is there some fixed semantic? (see linux/mtd/nand.h)

NAND_CMD_READ0 sets the offset to the start of a page. NAND_CMD_READ1 sets the offset to 256. This is only available on chips with a pagesize = 512.

What are you looking for ?

tglx

#2 lore raw
Quoted 4 lines · Thomas Gleixner

NAND_CMD_READ0 sets the offset to the start of a page. NAND_CMD_READ1 sets the offset to 256. This is only available on chips with a pagesize = 512.

Thanks, this is what I thought.

Do all NAND chips support the second half page reads? It seems for me - not.

Quoted 2 lines

What are you looking for ?

Nothing special, I'm just writing a NAND flash driver (which simulates NAND flash in RAM) and was a little bit confused since there is no comments (concerning NAND commands)in nand.h ...

Quoted 3 lines

tglx

Thanks for reply.

Signature · 3 lines
Best Regards,
Artem B. Bityuckiy,
St.-Petersburg, Russia.
#3 lore raw
Quoted 8 lines · Artem B. Bityuckiy
Quoted 4 lines · Thomas Gleixner

NAND_CMD_READ0 sets the offset to the start of a page. NAND_CMD_READ1 sets the offset to 256. This is only available on chips with a pagesize = 512.

Thanks, this is what I thought.

Do all NAND chips support the second half page reads? It seems for me - not.

Only the ones with 512byte pagesize.

Quoted 6 lines
Quoted 2 lines

What are you looking for ?

Nothing special, I'm just writing a NAND flash driver (which simulates NAND flash in RAM) and was a little bit confused since there is no comments (concerning NAND commands)in nand.h ...

Quoted 1 line

AFAICS, we use this command no more, as we always read / write page aligned.

tglx