On Monday 16 September 2013 19:42:27 Ray LI wrote:
> Hi,
>
> I would port Yaffs2 to my platform(STM32 + NAND Flash, uC-OS II).
> I'm worried about the usage of RAM.
>
> I read some information from "YAFFS Direct Interface (YDI) Integration
> Guide". It said, "For nand with 512byte pages, budget approximately 4kbytes
> of RAM per 1Mbyte of NAND. For 2kbyte page devices budget approximately
> 1kbyte per 1Mbyte of NAND." I have two questiones for this.
>
> 1.       Is the usage of RAM changing while I RD/WR the chunks of Flash?
> (e.g, I use 1kbyte while I use 1Mbyte of Nand, and when I use 2Mbyte I
> woule use 2kbyte  RAM.)

Yes, that is right.

>
> 2.       Does it means that if I use the whole space of flash (128Mbytes,
> 2kbyes page), I need 128kbytes.

Correct.

Note that these are just rough ballpark numbers and you might need more or 
less depending on what you are actually doing.

-- CHarles