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[ADV7480] About audio output from a laptop

Category: Software


 I have received support in this thread before, but I am still having trouble solving it,

so could you help me?

 [ADV7480] About laptop audio output 

After setting the EDID, the PC is plugged into the part (chipset),

but the PC recognizes the Display but not the Audio.

Although the ADV7480 side is ready to receive audio, the audio is not output from the PC.

Is there any mistake in the setting flow after setting the EDID?

I would appreciate it if you could check the attached Excel file from line 272 onwards.


Best regards.

  • Hi Tatsuya San,

            Please let us know, whether the reported behavior is observed in other sources like Player's and also check whether you can observe any frequencies from LRCLK, MCLK & SCLK of  ADV7480 Audio Port.

            Also note that " ADV748x cannot output audio over the CSI-2 bus. It can only output video over the CSI-2 bus. The only way to output audio is over the I2S output interface".

    Kindly note some of your register settings are different from the reference one. Please refer below,.

    For example.

      We found below additional settings which were not found in our reference script

    44 BF 12
    44 C0 00
    44 C1 00
    44 C2 00

    Also some values are differ from our reference script: For example

    Customer script:         Reference script:
      68 6C 0B                 68 6C 01;     HPA Manual Enable

      68 0F 1F                  68 0F 00 ;    Audio Mute Speed Set to Fastest (Smallest Step Size)

    Below register are present in reference script but this has been omitted in customer script

      68 83 00 ; Enable All Terminations

    Also some registers are added without values

    E0  71
    E0  40*
    68  F8
    68  01*
    E0  71
    E0   40*
    68  F8
    68  01*

    Please note that everything depends on the source. If the source doesn't get a valid EDID it may just begin transmitting in DVI mode with no audio and no HDCP.