From mboxrd@z Thu Jan 1 00:00:00 1970 From: Omair Mohammed Abdullah Subject: Re: Question: PCM short and long sync formats Date: Mon, 26 Mar 2012 18:59:43 +0530 Message-ID: <4F706F47.2090306@linux.intel.com> References: <4F69ABB0.2000706@linux.intel.com> <20120321115146.GC3226@opensource.wolfsonmicro.com> <4F7031AD.3090202@linux.intel.com> <20120326102650.GC3098@opensource.wolfsonmicro.com> <4F705BF3.5080905@linux.intel.com> <20120326120853.GP3098@opensource.wolfsonmicro.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by alsa0.perex.cz (Postfix) with ESMTP id 3E624249C1 for ; Mon, 26 Mar 2012 15:27:25 +0200 (CEST) In-Reply-To: <20120326120853.GP3098@opensource.wolfsonmicro.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: alsa-devel-bounces@alsa-project.org Errors-To: alsa-devel-bounces@alsa-project.org To: Mark Brown Cc: alsa-devel@alsa-project.org List-Id: alsa-devel@alsa-project.org On Monday 26 March 2012 05:38 PM, Mark Brown wrote: > On Mon, Mar 26, 2012 at 05:37:15PM +0530, Omair Mohammed Abdullah wrote: >> On Monday 26 March 2012 03:56 PM, Mark Brown wrote: > >>> I'm sorry but I still have no idea what you're talking about. You've >>> described PCM mode but not explained what "short frame sync" and "long >>> frame sync" mode are. > >> This diagram may explain things better: >> http://picpaste.com/pcm_fs-7dBlrkuW.png > > Sorry, that's not really clarifying things. It looks like "long frame > sync" is just I2S but presumably there's some difference? Yes, in I2S mode, according to the spec I have, the frame sync leads the MSB of the data by 1 bit clock cycle. Whereas the 'long frame sync' mode starts with the MSB of the data.