[Yaffs] RAM usage

Charles Manning manningc2 at actrix.gen.nz
Tue Sep 6 23:40:25 BST 2005


On Tuesday 06 September 2005 18:02, Evgeny Belyanco wrote:
> Hi!
>
> How I can calculate RAM usage for YAFFS (or YAFFS2) direct mode?

Most of the RAM used by YAFFS is in the tnode structures used to build the 
file trees. This uses approx 2 bytes of RAM per "chunk" of NAND.

Most people will use a NAND page as a "chunk", but you can use larger.

That means that if you are using NAND with 512byte pages, then for every 
1Mbyte of NAND you will need (1MB/512b = 2k chunks) * 2 bytes per chunk = 
4kbytes of RAM. 

For 2k page chunks you will need only 1 quarter of that.


>
> I will try to port YAFFS to uCOS-II.
>

Please be aware of licensing issues when using YAFFS with non-GPL code.

--- Charles



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