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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,

          Please check with other real time sources like consumer player, By default it will output encrypted content.

         Here we don't have ADV7480 eval board, So we are validating with ADV7842 board with Apple player and will check the 0x04 register & let you update the details.

    Thanks,

    Poornima

  • Hi Poornima, 
    Thank you for your checking. Waiting for your result. 
    We will take consumer players to test our ADV7480 board to make sure HDCP processing. 


  • Hi Poornima, 

    update Apple adapter testing result and register readback 


    Apple NB -> Apple Adapter -> ADV7480

    HDCP_KEYS_READ = 1

    HDCP_KEY_ERROR = 0 

    It means that HDCP is not a factor to block MIPI output 
     


    Is there parameter/factor/action to effect MIPI-out except HDCP ?

  • Hi Gen,

        It means that HDCP is not a factor to block MIPI output

          Yes, MIPI output does not consider the HDCP but the audio/video data must be decrypt the encrypted content which is send by source device.

    Also please note ADV7482 will have a key, you just will not use it.

    From the data sheet:

    This device is programmed with internal HDCP keys. Customer must have HDCP adopter status (consult Digital Protection, LLC, for licensing requirements) to purchase any components with internal HDCP keys

    Thanks,

    Poornima

  • Hi Poornima, 
    Customer has joined HDMI adopter and HDCP licensing.  
    We want to re-check EDID,  any idea for us? 

    Thanks. 

  • Hi Gen,

         Please let us know, Have you verified with other sources like consumer player (Samsung,Sony,LG etc).

         Then we will check about EDID.

    Thanks,

    Poornima

  • Hi Poornima, 


    Adaptor keep input HDMI signal into AD7480 (HDMI_Pin18_5V keep 5V input to ADV7480_PinC8)

    When ADV7480 is reset by MCU, and perform initial code (script 01-21) for ADV7480
    We found that there is no MIPI-out on ADV7480, have to do HDMI cable plug-out  and plug-in, then ADV7480 MIPI output works normally 
     
    We wonder that  can't always input 5V on ADV7480_PinC8

    Pls advise if there is suggestion for adaptor case 

     
  • Hi Gen,

        Could you please try 4.7K pulldown resistor on the RESET# pin and let us know MIPI output normally when you reset the ADV7480.

      Also please crosscheck with eval reference schematic.

    Thanks,

    Poornima

  • Hi Poornima, 

    RESET# connect 4.7K ohm to GND, and follow ADV7480 power up sequence to initial ADV7480 by I2C command , and then check MIPI-out work normally or not?
    It is correct? 

  • Hi Gen,

          YES.

         Please verify your schematic here & Our MCU is BF524 ,Advantiv EVAL-ADV7842-7511 Video Evaluation Board 

    Thanks,

    Poornima

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