AnsweredAssumed Answered

Vertical Video Rolling Problem

Question asked by 1Vu on Aug 27, 2012
Latest reply on Aug 30, 2012 by DaveD

Hi Guys,

I'm current having vertical video rolling problem and i don't know where the problem starts. This is my  current setup analog RGB 800x600 @ 35.2Khz and 55.8Hz generated by a signal generator feed into the ADV7842 outputting 24bit RGB into the DAC that output Analog RGB. The DACs work fine with a previous design for a different product. But when combining with the ADV7842 I'm starting to see video rolling. The image looks fine but it just won't stay still. I'm using script 5-2f on the AVES2.


The HSync and Vsync polarities coming out of the DACs are positive at 5V and have the same frequencies as the input, 35.2Khz and 55.8Hz.

Usually, video rolling happens when there is no Vsync present but in this case i have both.