[alsa-devel] AT32AP7000 (AVR32) + WM8510

Geoffrey Wossum geoffrey at pager.net
Fri May 23 01:11:31 CEST 2008

On Thursday 22 May 2008 05:48:41 pm Mark Brown wrote:
> On Thu, May 22, 2008 at 02:57:41PM -0500, Geoffrey Wossum wrote:
> > Looks like it should work to me.  Note that I do hear a pop from the
> > speaker the first time I try to play a file.  Here's a dump of the
> > registers while I'm trying to play a file with aplay.  I'm combing
> > through them right now to see if I can find anything that looks off.

> I'll have a look at it at some point, but not right now :) .  I should
> also have asked you if you could post your machine driver - if you'd
> rather post it off-list that'd be fine.

I'll have to do that tomorrow, I'm on my way out the door.

> I take it the digital audio looks fine with a scope - clocks at the
> correct rate, sensible looking data and so on?

The DACDAT signal looks pretty good.  However, I did notice something very 
odd.  The BCLK is dead on for whatever bitrate I'm doing.  However, the FRAME 
always runs at 44.1 kHz, no matter what I do.  From my understanding of I2S 
(which could be wrong), I would expect FRAME to run at the sample rate I'm 
playing back.  So if I'm playing back at 11025, I would expect BCLK to run at 
352 kHz and FRAME to run at 11 kHz.  I see BCLK running at 352 kHz, check.  
But frame is running at 44.1 kHz.  This doesn't seem right.  Am I missing 
something here?


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