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ADV7181 8bit DDR output

Question asked by jmdejoanelli on Aug 12, 2016
Latest reply on Aug 19, 2016 by JeyasudhaMuthuPerumal

Hi all,

 

I'm trying to configure an ADV7181c to convert an RGB XGA (1024x768@60Hz) signal to an 8-bit DDR YCbCr signal.

 

I am able to get video output, but the colours are all messed up, see attached "Capture.jpg". The XGA input video is the colour bar pattern shown in "SMPTE_Color_Bars.png" also attached.

 

I've tried playing with the CSC matrix values, but it seems like I'm just making random changes and random colours result. I've also tried adapting the test scripts used on the evaluation boards to make sure I'm using the right values, which doesn't seem to help me. One really frustrating thing is that basically the entire Color Space Conversion section is missing from the user manual. The majority of information I have is from the ADV7403 part which is similar and has this part of the manual included.

 

No matter the configuration, I always get a complete imbalance of green on the display. Most parts that are supposed to have green are lacking, and most parts that aren't supposed to have green are full of it.

 

Can anyone suggest anything to try?

 

I've looked on a lot of other posts and before you ask, I don't have the evaluation board, and don't have the option to use it unfortunately.

 

I've also attached our current configuration of registers in the chip in "ADV7181c Config.txt".

 

Thanks,

Josef

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