Re: interfacing USB flash disk

From: Jon S. (jonsquire2000_at_hotmail.com)
Date: 03/25/04 

Date: 25 Mar 2004 01:25:17 -0800

> You might want to consider AT45DBCxxx Dataflash cards.
> SPI interface, well documented in the datflash datasheets
> and low cost.
> Only drawback is that the size is currently limited to 8 MBytes.

I came to the same conclusion. Running a USB host on a 'real' embedded
system (8 & 16 bit) is non-trivial.

Interfacing to Compactflash can be done. Sandisk has got some
application notes on the topic:
http://www.sandisk.com/oem_application_notes.html

Using SD/MMC SPI compatible devices seems to be the simplest solution.
My only problem is that they are a bit to small for my application
(industrial equipment). Having a small card sounds great for a cell
phone. But not so great when you are working in a heavy industry.

Thus anyone know of any other (SPI comp.) form factor ?

I haven' looked yet, but any suggestions for SD/MMC connectors ?

I was also wondering what happens if you take out the card, is it
directly interfaced to the uP or is there some power-off sequence to
follow ?

Stijn