[alsa-devel] USB asynchronous mode feedback format

Daniel Mack zonque at gmail.com
Fri Oct 15 11:03:21 CEST 2010

On Fri, Oct 15, 2010 at 10:59:32AM +0200, Julian Scheel wrote:
> Am Donnerstag, 14. Oktober 2010, 17:39:13 schrieb Daniel Mack:
> > Well, even if it was, you should hear some sound. It might be distorted,
> > but if you don't get any output, the reason is somewhere else.
> > 
> > Did you check the schematics of your board in comparison to the
> > reference diagrams in the codec's datasheet? Are there any other things
> > to be considered maybe?
> > 
> > What about the voltage levels? Are they within the specs? I had a quick
> > look and it seems that Vdd on the codec has to be within 3.0 .. 3.6V,
> > while the signals you provide rather seem to be in the range of 5V? The
> > absolute maximum ratings say that Vdd must not be greater than 4.0V.
> Sorry for one more off-topic mail, but I rechecked it. Digital Input Voltage 
> is -0.3V to 6.5V, so my 5V clock voltage should be fine imho. Vdd is 3.0V on 
> my board...
> Do you maybe have any other thoughts what might be wrong here?

No, sorry. I think you're doing the right thing by analyzing the digital
stream carefully and checking the electrical components around the
codec. There's usually a ton of things to consider, but it's hard to
tell what to look for without having the same hardware.

Still, let me know what you find :)


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