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Black line on the Output from the ADV7282-M

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This FAQ was generated from the following discussion: Black line on the Output from the ADV7282-M

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Anonymous
  • Hi expert

      

    One thing you state that with a PAL input, the output is 480 lines long. Is the output 480 lines long for NTSC inputs too?

    [guoyuanyuan]: I can't confirm whether it is 480 lines long for NTSC inputs.

                                    I used a PROMAX TV PATTERN GENERATOR GV-698+ as NTSC inputs.

    The ADV7282-M outputs 487 lines of video in BT656-4 progressive NTSC mode. Could this be the cause of your issue?
    [guoyuanyuan]:I've always been confused. I must tell the receiver(backed device) the size of receiving data.

                                   I set it to 1440x480,but in fact 1440x507 size of data is received.


    Could you also try reading the registers 0x10 to 0x13 in the fail state.

    [guoyuanyuan]:I used a NTSC-M inpus when issue occured.

                                  Register 0x10--------0x0D

                                  Register 0x11---------0x42

                                  Register 0x12---------0x10(sometimes it is 0x00 based on different pattern)

                                  Register 0x13 ---------0x69

                                 When I unplug the signal source,it automaticlly enters free-run mode(single blue color,and black line disappeared,receiving data is 474 lines) ,the register values is showed as follows:

                                  Register 0x10--------0x0E

                                  Register 0x11---------0x42

                                  Register 0x12---------0x00

                                  Register 0x13 ---------0x78


    Could you also try recreating the issue on an ADV7282-M evaluation board. If you do not have one you can contact your local Analog Device's sales office to have one shipped to you. I can forward you an email address if you do not have one.

    [guoyuanyuan]:I have a ADV7282-M evaluation board in hand,and local Analog engineer Bob Gao have contacted me.

  • Hi Yuanyuan guo,

    It looks like you are programming the ADV7282-M correctly.


    One thing you state that with a PAL input, the output is 480 lines long. Is the output 480 lines long for NTSC inputs too?

    The ADV7282-M outputs 487 lines of video in BT656-4 progressive NTSC mode. Could this be the cause of your issue?


    Could you also try reading the registers 0x10 to 0x13 in the fail state.


    Could you also try recreating the issue on an ADV7282-M evaluation board. If you do not have one you can contact your local Analog Device's sales office to have one shipped to you. I can forward you an email address if you do not have one.


    thanks and regards,

    Robert


  • Dear expert

             I can't upload attachment to here, you can get attached file from the follwing link:

    https://sendspace.com/file/ymitic

  • Dear expert

          Thanks for your enthusiastic help!
           1) could you send me on the I2C writes that you are performing.

             I would like to double check that these are the same as our recommended scripts.

      -----guoyuanyuan:

            You can get recommended scripts named "ADV7282M_Cust-VER.4.7.txt" from attached file.

             The attached  file named "adv7282m_init_settings.txt" is the settings we are performing.

              Please searching for the keyword of "I2P AUTODETECT CVBS Single Ended In Ain 1, 480p/576p MIPI Out" in file

    "ADV7282M_Cust-VER.4.7.txt". I only change from "Ain 1" to "Ain 3",and i2c address 42 to 40.

           2) could you check that this issue occurs with a PAL input?

    ------guoyuanyuan:

              When using a PAL input, the image display is incomplete, so I can't confirm whether issue is still here,or it moved down. The PAL image size is still 720x480,I was confused.

            Please check attched file named "pal_images.zip"

           

           3) could you check that this issue occurs in interlaced NTSC mode (i.e. deactivate the I2P core).

      -------guoyuanyuan:

              The receiver side can't receive interlaced data.

  • Hi Yuanyuan guo,

    Sorry I was out last week.


    Setting the BT656-4 bit should result in the removal of ten lines of black video at the top of the image. Do you see this effect. I cannot think how toggling this bit could cause or remove a horizontal line issue.


    1) could you send me on the I2C writes that you are performing.

         I would like to double check that these are the same as our recommended scripts.

    2) could you check that this issue occurs with a PAL input?

    3) could you check that this issue occurs in interlaced NTSC mode (i.e. deactivate the I2P core).



    Regards,

    Robert

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