manningc2 at actrix.gen.nz
Thu Apr 4 15:26:37 EST 2002
> Does anyone have experience with AND flash? Does MTD support it?
You're looking at the Hitachi stuff right?
I have not used it, but I have had a good sniff around it when evaluating it
as a storage option against various others. NAND won in the end for the
* Simpler interface. The AND chips required some funky extra clocks.
* Cost: NAND prices started to fall rapidly. I believe they are now cheaper.
* Multi-source: As far as I can tell only Hitachi does AND. ie. supply
* Supply concerns: AND uptake by the market is uncertain, leading to future
Functionally AND is much the same as NAND. ie. page/block oriented stuff.
At the start of the investigation, AND had appeal because it was the cheapest
per bit. Since then however, NAND (Samsung/Toshiba) prices have fallen
dramatically and densities are increasing. This, I attribute largely to
Smartmedia uptake. As NAND rides the Smartmedia consumer wave, I expect to
see further price drops and density increases. Unless AND gets a similar
boost I expect it to fade away.
Without having investigated things too far, I'd expect AND to be able to slot
into mtd rather neatly as a NAND variant. AND commands are likely not the
same, but equivalent ones exist.
More information about the linux-mtd