Audio interface in Spartan 3E Starter kit

Hi All,

I like to use the Spartan 3E Starter kit as audio capture/playback
developping system as it has Linear Technology's DAC and ADC built in.
Ideally I want to be able to connect it to a computer speaker and
microphone just like a computer sound card. But I guess it requires
some external analog circuit and also the line-in and line-out
connector to interfac with the DAC and ADC.

Is there any reference design avaialbe for this type of external
circuit?  Or if there is any commercial expansion/add-on card to
support this purpose that works with Spartna 3E Starter Kit?

Thanks a lot!

William

FPGA wrote:
> Hi All,
> 
> I like to use the Spartan 3E Starter kit as audio capture/playback
> developping system as it has Linear Technology's DAC and ADC built in.
> Ideally I want to be able to connect it to a computer speaker and
> microphone just like a computer sound card. But I guess it requires
> some external analog circuit and also the line-in and line-out
> connector to interfac with the DAC and ADC.
> 
> Is there any reference design avaialbe for this type of external
> circuit?  Or if there is any commercial expansion/add-on card to
> support this purpose that works with Spartna 3E Starter Kit?

I've gotten audio output on the S3Esk DAC. See here for details:

http://www.fpga.synth.net/beginners/spi_test.shtml

Unfortunately, Digilent chose to put both the ADC and DAC on the same 
SPI interface, so because they have slightly different wordsizes and 
timing, making a system that can do simultaneous analog input and output 
is a bit more challenging. It also eats into your bandwidth.

If you're interested in audio applications of FPGAs, the site mentioned 
above has links to a community of folks who are working in that area.

Eric