29 Oct
2011
29 Oct
'11
3:58 p.m.
On Sat, Oct 29, 2011 at 2:20 AM, Christoph Kuhr <christoph.kuhr(a)web.de> wrote:
I'm still not clear on it. I was having a little trouble following
the ideas from Dale and Fons, too. How would digital audio interfaces
be different from adc/dac?
The data transfer to/from the PC is packetized, no matter what kind of
interface you use to transfer data. It's an asyncrhonous process that
depends on when data is sent to or ready to be read from the device.
My idea is to control adc/dac directly from an FPGA (lots of them,
potentially). I'm familiar with I2C and SPI interfaces on adc/dac,
and there's a few differences between devices (order of bits from MSB
to LSB or LSB to MSB for instance). They are all basically the same,
but the handling of the same data is a bit different.
I have a few questions
Is digital audio syncronized or packetized? What's the clock rate?
What's the data transfer bandwidth? Is there an IC you can use just
like adc/dac?
Chuck
> A
suggestion: start with providing just digital interfaces: ADAT, and
> MADI if you're ambitious. Both are quite straightforward. ...
> I wouldn't forget poor old AES (including SPDIF.)
How about a standard adc stage with FPGA processing/routing and I2S bus. For
ADAT there are already the OPTOGEN and OPTOREC modules (dont have the links
right now). Then ADAT and spdiff/aes-ebu as standard interfaces. An optional
XMOS low cost board for avb, which is capable of I2S. And a FPGA extension
board for MADI and ieee1394 also connected via I2S.
I kinda like the idea... could be highly flexible...
Second step: same device as DAC...
Sorry fucked up the subject...
Ck