Andrew Lunn wrote: > On Thu, Nov 22, 2007 at 05:42:11PM +0100, Tom Deconinck wrote: >> Hello, >> >> Does anyone know if there exists a driver for the AT91 TWI peripheral? >> It's Atmels implementation of I?C and it's used on the AT91SAM7S >> family (and derivatives). >> I would create a driver that fits in the eCos I?C driver (master >> only), but I wanted to check to make sure nothing alike already >> exists. > > I've been involved in a none eCos project which used an AT91SAM7S and > the TWI port. This turned out to be more difficult than expected. If > you don't feed it data fast enough it stops the transfer mid message > with an abort of something. Also, there is no DMA for this device. So > you need to make sure your other interrupt handlers are fast or you > run into problems.
Hmm, I've done an AT91 TWI implementation for eCosPro, and didn't have abort problems. But then there are caveats on its use as it isn't a brilliant fit with the I2C API - in particular there's no way to send NACKs without a STOP, and (I might be misremembering here - it's been a while) I think possibly no way to do a STOP not in conjunction with a transfer. Jifl -- --["No sense being pessimistic, it wouldn't work anyway"]-- Opinions==mine
