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ADV7480 - Compatibility Issue

Hi , 
We met two kind of situation, one is no display on screen, the other is to display abnormally. 

1. Laptop -> Apple Type C to HDMI adapter ->  HDMI input to ADV7480 -> SoC -> Display on screen 
Test result is that there is no display on screen.



2 Apple Laptop -> HDMI input to ADV7480 -> SoC -> Display screen
Test result is that display isn't stable. . 



Other Windows NBs + Apple adapter : Always Fail

Apple NB + Apple Adapter: Always Fail

Other Windows NBs + other adapter : PASS

Apple NB+ other adapter: PASS

Apple NB connect to ADV7480 with HDMI input :  Fail rate is too high.



Is there a compatibility issue between Apple products and ADV7480? 
Is there suggestion or register can adjust this situation? 

Thanks. 



Other Windows NBs + Apple adapter : Always Fail Apple NB + Apple Adapter: Always Fail Other Windows NBs + other adapter : PASS Apple NB+ other adapter: PASS
[edited by: gen at 5:36 AM (GMT -5) on 26 Nov 2021]
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  • Hi Gen,

          Snow noise or not stable display is an indication that HDCP authentication has failed but the source continues transmitting video.  Normally on failure it is the responsibility of the source to transmit a black screen or  the source will not output anything       

           Our eval board software handles all the transactions required for proper HDCP operation. Above mentioned HDCP requirement related handling's are we have taken care in our ADV7480 Eval software. Please crosscheck.

           Please ensure the below HDCP requirement has been taken care in your software,

     1. After the part has powered up, it is recommended to wait for 1 ms before checking the HDCP_KEYS_READ and HDCP_KEY_ERROR flag bits. This ensures that the ADV7480 had sufficient time to access the internal HDCP ROM and set the HDCP_KEYS_READ and HDCP_KEY_ERROR flag bits.

    2. After an AKSV update from the transmitter, it is recommended to wait for 2ms before checking the HDCP_KEYS_READ and HDCP_KEY_ERROR flag bits. This ensures that the ADV7480 had sufficient time to access the internal HDCP ROM,and set the HDCP_KEYS_READ and HDCP_KEY_ERROR flag bits.

    3. A hardware reset (that is,reset via the reset pin) does not lead the ADV7480 to read the KSV or the keys from the HDCP ROM

    4. The ADV7480 takes 1.8 ms to read the keys from the HDCP ROM

    For more details Please refer section 5.3.8 - HDCP Support in ADV7480 Reference Manual.

    Note: In addition, specific timing requirements have to be met generally. For example, the source has to allow at least 100 milliseconds after writing the AKSV to the sink device before reading the Ro value.

    Thanks,

    Poornima

  • Hi Poornima, 
    Thanks to reply quickly. 

    there are some questions need your clarification

    1. After the part has powered up, it is recommended to wait for 1 ms before checking the HDCP_KEYS_READ and HDCP_KEY_ERROR flag bits. This ensures that the ADV7480 had sufficient time to access the internal HDCP ROM and set the HDCP_KEYS_READ and HDCP_KEY_ERROR flag bits.


    2. After an AKSV update from the transmitter, it is recommended to wait for 2ms before checking the HDCP_KEYS_READ and HDCP_KEY_ERROR flag bits. This ensures that the ADV7480 had sufficient time to access the internal HDCP ROM,and set the HDCP_KEYS_READ and HDCP_KEY_ERROR flag bits.

    >>delay 2ms, which step in script file(01-21) need to add 2ms?



    Thanks.

  • Hi Gen,

      This HDCP sequence need to be followed in the software not in script.

      Please check with other real time sources like consumer players - Samsung,Panasonic etc and let us know.

    Thanks,

    Poornima

  • Hi Poornima,

    SOC is Qualcomm which include MIPI RX to receive MIPI from ADV7480. 
     Front HDMI source is Apple NB or Apple adapter ( type c to HDMI)

    We follow 01-21 in script, HDCP processing should be executed in ADV7480 when adapter plug in. 

    as your mentioned, AKSV update completed, should wait 2 ms

    we don’t understand this step, when will execute this AKSV in ADV7480?

  • Hi Gen,

         By default HDCP decryption would take place in the ADV7480, so the ADV7480 part itself will take care the HDCP related authentication.

         These kind of HDCP sequence need to take care only in the software.

        Please let us know your ADV7480 part details to check whether it is an -P or Non -P part.

    Thanks,

    Poornima

Reply
  • Hi Gen,

         By default HDCP decryption would take place in the ADV7480, so the ADV7480 part itself will take care the HDCP related authentication.

         These kind of HDCP sequence need to take care only in the software.

        Please let us know your ADV7480 part details to check whether it is an -P or Non -P part.

    Thanks,

    Poornima

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