Re: [ECOS] TWI/I?C driver for AT91

["Tom Deconinck" <t dot deconinck at gmail dot com>]

On Nov 22, 2007 7:27 PM, Andrew Lunn <andrew@lunn.ch> 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.
>
>     Andrew
>

Thanks for the heads up. I had noticed there are no DMA channels to
the TWI controller, but didn't think it would be much of an issue.
I'll give it a try and see where it takes me. I need I2C anyway, so
using the eCos framework makes some sense.

Tom

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