From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Ujfalusi Subject: Re: McBSP in TDM for audio codec Date: Fri, 15 Jun 2012 09:34:48 +0300 Message-ID: <4FDAD788.9060407@ti.com> References: <4FCE0127.8080404@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: Received: from na3sys009aog116.obsmtp.com (na3sys009aog116.obsmtp.com [74.125.149.240]) by alsa0.perex.cz (Postfix) with ESMTP id 8028E2454E for ; Fri, 15 Jun 2012 08:34:36 +0200 (CEST) Received: by lbbgh12 with SMTP id gh12so2288422lbb.25 for ; Thu, 14 Jun 2012 23:34:33 -0700 (PDT) In-Reply-To: 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: learnom learnom Cc: alsa-devel@alsa-project.org List-Id: alsa-devel@alsa-project.org Hi, On 06/06/2012 04:56 AM, learnom learnom wrote: > I want to control these channel0, 1, 2, 3 independently. > For example, lets say, > 1) If I want to transmit the data in channel 1 only, i want to see the > channel0 null, channel1 with data, channel 2 null, channel 3 null. > = > 2)I want to transmit data at the same time, channel 1 (data) , channel2 > (Data), channel3 data, channel(data). > = > Can you please let me know how to recognize that the user is sending from > which channel, and how to setup for these two scenarios. User space need to make sure that it is placing the data to the correct channel. The McBSP/sDMA just see a stream of data in a memory. McBSP do have TDM mode where you can have limited control over how the channels are handled, but it still handle the data as stream and you can on= ly tell which slot it should use and which one to ignore. This TDM programming mode is not implemented since we did not needed it so far and without a cod= ec it is kind of hard to test it (well, with a scope the channels can bee observed but that would be all). -- = P=E9ter