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AD9984A wrong output

Question asked by staringlizard on May 19, 2015
Latest reply on May 29, 2015 by mattp

Hi EZ !


I had a board made which is utilizing this device. I use VGA as input with 1280x720 @ 60Hz (I have tried some other format with same problem). I use the scripts that you have supplied (see below in this post).


The device works in the meaning that it is outputting data, HS, VS etc. But I am not getting correct output.

For blue channel (for example), no matter what I am feeding into the blue input analog pin (BAIN0, see picture analog_blue_rgb_signal.bmp), I will always get:


blue 0 = 1

blue 1 = 0

blue 2 = data (toggles)

blue 3 = 0

blue 4 = 1

blue 5 = 0

blue 6 = 0

blue 7 = 0

blue 8 = 0

blue 9 = 1


On the other side I will get something like the attached picture (keep in mind that the picture is taken after FPGA and frame buffer) (picture.jpg). I just get some purple dots (flickering back and forth) on a purple background.


Could the device be broken somehow? Is there something I am missing here ?

In my world, either the device is working or it is broken. But this is different. I can talk I2C with the device, change settings, get output from it etc. without problem.





<devicevalues name="AD9984">

  <registerval addr="0" value="17"/>

  <registerval addr="1" value="103"/>

  <registerval addr="2" value="32"/>

  <registerval addr="3" value="168"/>

  <registerval addr="4" value="128"/>

  <registerval addr="5" value="64"/>

  <registerval addr="6" value="0"/>

  <registerval addr="7" value="64"/>

  <registerval addr="8" value="0"/>

  <registerval addr="9" value="64"/>

  <registerval addr="A" value="0"/>

  <registerval addr="B" value="64"/>

  <registerval addr="C" value="0"/>

  <registerval addr="D" value="0"/>

  <registerval addr="E" value="32"/>

  <registerval addr="F" value="64"/>

  <registerval addr="10" value="0"/>

  <registerval addr="11" value="32"/>

  <registerval addr="12" value="0"/>

  <registerval addr="13" value="32"/>

  <registerval addr="14" value="4"/>

  <registerval addr="15" value="10"/>

  <registerval addr="16" value="4"/>

  <registerval addr="17" value="4"/>

  <registerval addr="18" value="10"/>

  <registerval addr="19" value="40"/>

  <registerval addr="1A" value="20"/>

  <registerval addr="1B" value="51"/>

  <registerval addr="1C" value="255"/>

  <registerval addr="1D" value="120"/>

  <registerval addr="1E" value="52"/>

  <registerval addr="1F" value="146"/>

  <registerval addr="20" value="7"/>

  <registerval addr="21" value="32"/>

  <registerval addr="22" value="50"/>

  <registerval addr="23" value="20"/>

  <registerval addr="24" value="8"/>

  <registerval addr="25" value="111"/>

  <registerval addr="26" value="46"/>

  <registerval addr="27" value="224"/>

  <registerval addr="28" value="143"/>

  <registerval addr="29" value="2"/>

  <registerval addr="2A" value="0"/>

  <registerval addr="2B" value="0"/>

  <registerval addr="2C" value="0"/>

  <registerval addr="2D" value="8"/>

  <registerval addr="2E" value="32"/>

  <registerval addr="3C" value="3"/>