On our product which uses ADV7181C, we are observing blank video out from the decoder.
Please refer to register dump in the attached logs and let us know what could have gone wrong with the decoder chip.
1) How is your test configuration set up? sources, sinks, resolutions, is it a custom board, can you duplicate the problem with an evaluation board
2) Has this board worked in the past or is this a new proto-type board?
1) The source video resolution is 1080i. It is a custom board.
We cannot reproduce this issue on other boards.
This is observed on a particular board and to debug this, we need to understand if register settings in ADV are appropriate for 1080i decode.
2) Video decode had worked on this board in the past.
1) 0x05[7:0] = 0x01 for component video
2) 0x03[5:3]=0x0c implies you want 8-bit BT656. 1080i is 74.25MHz pixel clock so 8-bit output would need 148.5MHz clock. LLC is limited to 110MHz. The output needs to change to 16 or 20 bit output.
3) PRIM_MODE is set up wrong
Please refer to additional register dumps for working and non working cases for 2 resolutions, viz 480i and 1080i.
Also could you let us know the consequence of wrong PRIM_MODE value and recommended value for component 1080i resolution.
If the PRIM_MODE or VID_STD are incorrect, the ADV718C will not output the correct image as it will be incorrectly configured. In these case it will normally output a blue screen (FreeRun) at the programmed PRIM_MODE and VID_STD setting.
As GuenterL pointed out above, for 1080i, the output format needs to be 16it or greater.
You mentioned that this was working on a different board , it would be good to do a comparison between the boards. It is impirtant to check REF pins etc.
Our current recommended setting can be downloaded from the ADV7181C_Evaluation_Software link on the design support page
Here there is examples of 480i and 1080i scripts and settings.
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