AnsweredAssumed Answered

Commands needed to transmit ARC

Question asked by reshmi on Aug 30, 2012
Latest reply on Sep 5, 2012 by DaveD



We have a custom board that uses ADV7612 as the HDMI receiver and ADV7511 as the HDMI transmitter. We also use the ADI app to perform most of the HDMI command processing.


Our unit is supposed to be able to receive an ARC from a TV, in which case we function as an audio unit, and also be able to send ARC to an audio unit, in which case we act as a TV.


The ADI HDMI app I think does the handling of all the messages sent by the TV to us, and we are able to receive ARC correctly.


But when we switch to a TV mode, I am not able to get the audio unit to see our ARC stream correctly. I am making sure that I send 'Request ARC Initiate' to which I get 'ARC Initiate' from the audio device, and then I send 'Report ARC Initiate'. I see all these messages coming in correctly. But the audio device (in this case an AVR that can receive ARC) does not see it. I suspect that there are other messages to be sent out from a TV device in order to function as an ARC transmitter, which I am not doing now and hence the audio device does not see the stream. Am I missing anything?


Another question I have is about this concept of 'Active Source' which is repeatedly mentioned in HDMI specification. I am not clear if we should become an active source if we are transmitting an ARC stream also?


I know that the ARC stream itself is working. This was verified by connecting the HDMI cable to Audio Precision HDMI ARC receive connector, and the Audio Precision sees our stream and can play it out.


I also verified that the audio device(AVR)'s ARC functionality is working by connecting it to a TV that can send out ARC.


Any pointers will be helpful.