Am Freitag, 15. Oktober 2010, 11:03:21 schrieb Daniel Mack: > 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 :) Just figured out what went wrong. The PCM1794A requires the I2S signal to contain 24 bit. So when running in 16 bit mode one has to fill up with 8 zero bits. Now I doubled the BCLK so that I would be able to send 32 bit to the DAC. Still am fighting a bit with the AT91's SSC controller to send only one package per L/R frame, but in general I am seeing a proper signal behind the DAC now! Regards, Julian _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
