Hello all, Most HD Audio codecs now on the market support some type of impedance sensing in hardware, in addition to simple detection of whether a jack is physically plugged in. Almost all HD Audio codecs also feature some form of multi-tasking support, to allow the analog I/O ports to change functions on the fly. The paper that Hakon provided a link to was the catalyst for various chip companies to implement the impedance sensing functionality. Appendix D of my book, High Definition Audio for the Digital Home, goes into this subject much more deeply, and was written after many hard lessons were learned. http://optimalsound.net/hdaudiobook.html I led the HW and SW teams for the first chip company to implement impedance sensing, so the information in the appendix is very real, and not theoretical. Best, David Roach david.roach@xxxxxxxxxxxxxxxx www.optimalsound.net ------------------------------ > Subject: [wdmaudiodev] Re: Discovery of Analog Audio Device > Date: Tue, 6 Nov 2007 11:53:43 -0800 > From: Hakon Strande <hakons@xxxxxxxxxxxxxxxxxxxxx> > > I found it > > http://www.microsoft.com/whdc/device/audio/analog_impedance.mspx > > Sincerely, > > Hakon Strande | Windows Sound Team PM | (p) 425.705.0637 > ****************** WDMAUDIODEV addresses: Post message: mailto:wdmaudiodev@xxxxxxxxxxxxx Subscribe: mailto:wdmaudiodev-request@xxxxxxxxxxxxx?subject=subscribe Unsubscribe: mailto:wdmaudiodev-request@xxxxxxxxxxxxx?subject=unsubscribe Moderator: mailto:wdmaudiodev-moderators@xxxxxxxxxxxxx URL to WDMAUDIODEV page: http://www.wdmaudiodev.com/