On Tue, Feb 19, 2008 at 04:59:00PM -0800, Eric Miao wrote: > Shouldn't the clock rate for AC97 be 12.288MHz? Though the clock is > actually provided by external, the clock hierarchy implies an internal > clock of 12.288MHz on both PXA25x DM and PXA3xx DM (unfortunately, not > specified on PXA27x DM) The AC97 bit clock should be run at 12.288MHz but this is a separate thing to that. The AC97 controller needs its own clocking for at least some things that need to work when the AC97 link is not active (like reset operations). The controller also provides an external 24.576MHz AC97_SYSCLK signal which is used by some designs to clock the primary codec - in those designs the bit clock is derived from it, but it may also be derived from another source. _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
