Re: [Yaffs] Using yaffs1 with 2kb NAND page

Top Page
Message as email
+ (text/plain)
+ (text/html)
Delete this message
Reply to this message
Author: Charles Manning
To: Bettega Stefano
CC: yaffs
Subject: Re: [Yaffs] Using yaffs1 with 2kb NAND page
Hello Stefano

My apologies for a late delay. I have been away from my office for the
Christmas break.

I looked at the datasheet and I see the following things in the parameter
page structure:

* The device supports partial page programming and has 4 partial pages. ie.
each page can be treated as 4x512byte sub-page.
* These pages may be programmed individually.

That suggests that this part could be uses in Yaffs1 mode, just with 256
pages of 512 bytes rather than 64 pages of 2k.

* It also says a maximum of 4 programs per page. Since Yaffs1 requires a
page be programmed twice: once for programming and once for setting the
deletion flag, the above scheme would require 8 programming operations per
* It also wants 4 bytes of ECC correction per page. Using Yaffs1 ECC only
gives 1 bit per 256 bytes. That is not as good.

Further, elsewhere it recommends only programming pages in sequential order
within a block. Yaffs1 requires being able to program in any order to write
deletion markers.

Therefore I cannot recommend using Yaffs1 on this part.

If you use one of the parts with built-in ECC like the MT29F1G08ABADAWP
then it is very simple to get Yaffs2 working on that part.



On Thu, Dec 28, 2017 at 9:40 PM, Bettega Stefano <
> wrote:

> Hello Charles,
> I've read the NAND datasheet in deep, ad it seems that I can't use the
> NAND splitting the page in subchunks to emulate four 512 bytes pages.
> As it says (page 15): "NAND Flash memory array is programmed and read
> using page-based operations and is erased using block-based operations", I
> think I have to switch to yaffs2 and handle all of its flavors.
> Glad to have your opinion about it.
> Thanks and regards,
> Stefano
> ---
> Questa e-mail è stata controllata per individuare virus con Avast
> antivirus.
> _______________________________________________
> yaffs mailing list