Lpc2000

brendan
 >I think the basic problem is that the LPC213x SPI can only handle 8-
 >to 16-bit transfers, and the Atmel device requires longer ones.

I don't know of any SPI which makes longer frames than 16bit.
If you need more you have to send more frames.

Only if the CS is really deasserted between frames you need to tweak
the CS.
(BTW: The SAMs have the problem the otherway round, for DMA transfers
they do not deassert CS which some chips need.)

> A simple way around this is to "bit-bang" the interface (i.e. use 
> all pins as GPIO and drive them all in software). This is easy 
> enough to do for SPI interfaces. Performance might take a bit of a 
> hit, and you have to watch how interrupts may interfere with timing.

A bit overkill. Using IO for CS would be enough.
Esp. if it you go for highvolume like with a dataflash.

-- 
42Bastian