Ron Cococcia wrote: > In a setup I'm working with, I have a motherboard (815 w/82801BA-ICH2) that > has an onboard/primary (00) AC97 codec (AD1885). We've been playing around > with adding a CNR card that would have a different/secondary (01) codec on > it (CS4299). [...] > The onboard chip is generating (I think) a BIT_CLK signal, and (I think) the > CNR is as well (it's wired to an oscillator).
There is exactly one clock signal on the AC'97 bus, driven either by the primary codec or (more often) by the controller. I guess the oscillator on the CMR card is for a configuration where the CS4299 would be the primary codec. > I'm worried that both chips generating a BIT_CLK might cause > jitter, and could cause audio quality issues. Even worse, two different clocks would drift apart over time, which would make it impossible to send synchronized samples to both codecs. Having two independent clocks in an audio system would require resampling. The second codec in an AC'97 system should not affect the primary one. HTH Clemens ------------------------------------------------------- This SF.Net email is sponsored by: IBM Linux Tutorials Free Linux tutorial presented by Daniel Robbins, President and CEO of GenToo technologies. Learn everything from fundamentals to system administration.http://ads.osdn.com/?ad_id=1470&alloc_id=3638&op=click _______________________________________________ Alsa-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/alsa-devel
