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Regarding CEA timing vs VESA timing

Question asked by Blomman on Dec 14, 2011
Latest reply on Dec 14, 2011 by GuenterL

Hi Dave,

 

we now have the transmitter AD9889B and the ADV7611 receiver devices up and running on the videoboard. I have some questions.

 

  1. When I'm reading the AD9889B hardware manual it says the device is supporting all 59 modes in the CEA 861-D standard.

          From what I have understand this is a digital TV standard. The documentation is very detailed about the timing of the DTV fomats

          but I can't find information about what PC graphic modes that the AD9889B supports.

          Our concept is to take one PC and two camera  DVI sources in to the ADV7611 receivers, put them into a FPGA and from there

          have the opportunity to send them to the AD9889B device acting as the back-end to a DVI monitor.

          When I did some laborations by using a PC as front-end and generated different PC DVI graphics I noticed that standard video-

          graphics like VESA VGA(640x480), SVGA(800x600) etc. in aspect ratio 4:3 all worked fine. Doing the same with a 16:10 format

          (like 1280x800) and 16:9 format (like 1280x720 HDTV) the result was also good, I had a good stable picture on my DVI monitor.

          When i tryed to put the VESA format of SXGA(1280x1024) in aspect ratio 5:4 I got a monitor acting instable.

           I even tryed with a another DVI monitor(ho has a preferabla native of 1280x1024), but the result was the same, instable monitor.

           What could be the reason of this behavior? Does the ADV7611 or the AD9889B devices not support the VESA SXGA mode?

 

 

     2.  Do you know any other user that have faced the same problem with this devices and video mode?

          Is it possible to affect the video timing out of the AD9889B device in a possitive way by generate a internal DE signal

          from the input sync signals instead of using the DE signal that is comming in to the device or any other working soloution?

          If you Dave,  any of yuor colleagues, or anyone else could help me out, I'll really would appreciate that!

 

Best regards

/Kenneth

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