From mboxrd@z Thu Jan 1 00:00:00 1970 From: Takashi Iwai Subject: Re: [RFC] Add dB scale information to AK4xxx codec Date: Mon, 04 Sep 2006 13:35:31 +0200 Message-ID: References: <20060903155357.GA10408@tarte.seehuhn.de> <20060904111303.GA24842@localhost.localdomain> Mime-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <20060904111303.GA24842@localhost.localdomain> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: alsa-devel-bounces@lists.sourceforge.net Errors-To: alsa-devel-bounces@lists.sourceforge.net To: Jochen =?ISO-8859-1?Q?Vo=DF?= Cc: alsa-devel@lists.sourceforge.net List-Id: alsa-devel@alsa-project.org At Mon, 4 Sep 2006 12:13:06 +0100, Jochen Vo=DF wrote: > = > Hi Takashi, > = > On Mon, Sep 04, 2006 at 11:58:57AM +0200, Takashi Iwai wrote: > > > From table 17 (page 35) of the AK5365 specs I think that IPGA and DATT > > > are only separate units inside the chip, but should be treated as one > > > continuous scale for the purpose of the driver. The table looks like > > > the input volume can be adjusted in steps from "mute" to +12dB. Why > > > would we want two controls here? > > = > > Actually they are treated independently in the chip. IPGA works like > > a preamp, and the total volume is IPGA + DATT. Even if you set a > > value to IPGA with MSB, say 0x82, DATT won't be changed and the old > > value is kept. And it's vice versa - if you set 0x02 later, IPGA will > > stay as 0x82. This is so, at least with AK4524 and AK4528. Possibly > > this was changed on AK5365, though... > Did you have a look at table 17? I think the old behaviour was better. Yes, the exactly same table appears in AK4524 datasheet, too. The only question is whether they really behave _indenpendently_. On AK4524, IPGA and IATT are actually two different values. As I wrote, 0x82 only changes IPGA value but doesn't change IATT. 0x02 changes only IATT but not IPGA. And the total volume is IPGA + IATT. Takashi ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easi= er Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=3Dlnk&kid=3D120709&bid=3D263057&dat=3D1= 21642