From mboxrd@z Thu Jan 1 00:00:00 1970 From: Manuel Jander Subject: Re: Re: au88x0 modem Date: Fri, 16 Sep 2005 23:34:41 +0200 Message-ID: <1126906481.12111.7.camel@localhost.localdomain> References: <4325AEA3.1090602@netvigator.com> <20050913000909.GB19713@tecr> <20050913085552.GA2655@titan.lahn.de> <20050913173529.GD31269@sashak.softier1.local> <20050913174930.GA5816@titan.lahn.de> <4327DA14.3040205@netvigator.com> <20050914205608.GD14657@sashak.softier1.local> <20050915091158.GA7314@titan.lahn.de> <20050915092155.GA7328@titan.lahn.de> <20050915143533.GB23218@sashak.softier1.local> <20050915204345.GC27700@sashak.softier1.local> <432AD226.6010706@netvigator.com> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <432AD226.6010706@netvigator.com> Sender: alsa-devel-admin@lists.sourceforge.net Errors-To: alsa-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: Alsa-devel list List-Id: alsa-devel@alsa-project.org Hi, > The easy way is to create a PCM device "modem" on au8810 > > > DMA -> FIFO -> SRC -> MIXIN --------> MIXOUT -> MC97(Modem Out) > | > +-----------> MIXOUT -> EQ -> AC97(Audio Left) > > Modem Speaker On or Off > > +-> MIXOUT -> EQ -> AC97(Audio Right) > | > DMA <- FIFO <- SRC <- MIXOUT <- MIXIN <-------- MC97(Modem IN) > > > or > > > DMA -> FIFO -> SRC -> MC97(modem) (Playback) > > DMA <- FIFO <- SRC <- MC97(modem) (Capture) > Remove the samplerate converter, it does not make any sense on a modem. You will only loose signal precision with the samplerate converter anyway, and there are very few of them. A direct route from the fifo to the modem codec will do it and the modem signal device will run at the codec native samplerate without any precision loss. > > What is the difference between modem application and audio application ? Nothing. The only modem extra functionality is the ability to switch the modem line off/on hook. It just sends and captures QAM modulated signals. > Do the modem application open two PCM streams (one for playback and the > other for capture )? Yes, it should be full duplex. This will require 2 DMA's. > Where is the class SND_PCM_CLASS_MODEM specificed in the driver ? At least i did not. Best Regards, Manuel Jander ------------------------------------------------------- SF.Net email is sponsored by: Tame your development challenges with Apache's Geronimo App Server. Download it for free - -and be entered to win a 42" plasma tv or your very own Sony(tm)PSP. Click here to play: http://sourceforge.net/geronimo.php