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RE: FAT32 over NAND


> From: Rutger Hofman
>
> Hmmm. I am not familiar with 'mass storage driver'. I assume that it is
> a generic Windows thingy for block devices -- I know nothing about
> Windows? Or do you mean USB? If you do not mean USB, how is Windows
> going to access the device? Through some network? a bus? some other means?
>
> If it goes through USB, I guess you need the uC to intermediate between
> USB and the Flash chips. In that case, there are possibilities besides
> FAT32.

Although Himanshu hasn't said so explicitly, I infer that they've got a
board with a NAND flash soldered onto it, with an external interface like
USB, as opposed to Ethernet. If the interface is USB, then FAT is the _only_
choice, because USB presents a block-oriented interface, not a file-oriented
interface. And since any external device will be writing in the FAT file
format, an FTL designed specifically for FAT is needed.

If the design isn't cast in stone yet, one possibility is to put an SD
controller on the board. This eliminates the need for an FTL, requiring only
a minimal software interface between the external USB interface and the SD
controller. For small quantities, one might even consider putting a complete
SD socket and card on the board, even if it's not accessible outside the
box, since they're pretty cheap. Then, in development, one can pull the card
out and write to it on another machine, before the USB interface is even
working.

--

Ciao,               Paul D. DeRocco
Paul                mailto:pderocco@ix.netcom.com


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