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ADV7842 VGA Detection with MacPro and Apple DisplayPort to VGA Adaptor

Question asked by rpmarchand Employee on Nov 7, 2016
Latest reply on Nov 16, 2016 by rpmarchand



i'm currently using the ADV7842 in a design that is being used for both analog and digital video inputs.  I'm having an issue where the ADV7842 cannot detect properly with a MacBook with the following formats: 1920x1080 60Hz video.  I have successfully been able to detect video formats with other formats (for example 800x600 60Hz, 1280x1024 60Hz, and 1600x1200 60Hz).  Only 1080p 60Hz fails to detect properly.  


I am using a MacPro 4.1 as detailed below:

Mac Pro (Early 2009) - Technical Specifications 

my particular model is using the NVDIA GeForce GT 120 GPU and is the 2.66GHz Xeon Quad-Core 


The adapter that I am using from the Mini DisplayPort to VGA adapter is detailed below:

Mini DisplayPort to VGA Adapter - Apple 


I tried the EVAL-ADV7842 and the result is that the video is shifted 

I am using CP registers 0xB1, 0xB2, 0xB3, 0xB4, 0xB5  to determine input resolution.


Do you have any suggestions on what could be wrong?