there is a black gap at the top of image

Hi Yuanyuan Guo,

Do you see this issue with NTSC inputs but not PAL inputs ?

If so the issue is probably due to the output format from the ADV728x.

By default the ADV728x will output in ITU BT656-3 timing format (this is true for MIPI CSI-2 output models too).

If the receiver chip is expecting ITU BT656-4 format then this can result in 10 dark lines appearing at the top of the screen in NTSC mode. This is because ITU BT656-3 format has 10 more lines of vertical blanking than ITU BT656-4 format.

You can program the ADV728x to output in ITU BT656-4 format. Set User Map, register 0x04 bit[7] to 1. This should solve your issue.

Regards,

Robert Hinchy

Senior Applications Engineer,

Digital Video Products Group,

Analog Devices Inc.

Hello  expert

    Thanks for your help!

    Problem has been resolved by setting User Map register 0x04 bit[7] to 1,

However, there is a black line in the bottom of image.why?

    Please refer to the attached file to get video,thank you!

Hi Yuanyuan Guo,

Do you have ACE enabled?

If so your issue could be the same as the one detailed at the link below:

https://ez.analog.com/message/161266#161266

Regards,

Robert

Hello expert

         The ACE function is disabled .

         Modification is Invalid when writing 0x00 to User Sub map 2, register 0x84 whether  ACE function is disabled or enabled.

         Could you give me more try to fix this issue?   Because we can only communicate once within a day,

Thank you very much!

Hi guoyuanyuan@longcheer.net,

As this appears to be a separate issue I have posed this in a separate engineering zone post.

https://ez.analog.com/docs/DOC-11849#comment-5053

regards,

Robert Hinchy