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Altera_Forum's avatar
Altera_Forum
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17 years ago

DE2-70 and video_sync_generator

Hi

I am trying to make a design using the video_sync_generator component on a de2-70 board, but i am getting strange results.

For testing purposes,i connected the tree color component(Red,Green and Blue) to Vcc,so i expected to get a nice white screen but the screen is all black.The synchronization signals (VS and HS ) seem ok (the screen correctly detect the resolution). I joint a picture of my connection , if anyone have an idea or ran onto the same problem

Thanks

4 Replies

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    17 years ago

    Hi.

    Don´t connect the R,G,B to Vcc, instead assign a value to them, while the scan time is the correct.

    Speaking about H signal, it is after H blanking, and before the next H blank pulse.

    Regards.

    Alberto.
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    17 years ago

    --- Quote Start ---

    Hi.

    Don´t connect the R,G,B to Vcc, instead assign a value to them, while the scan time is the correct.

    Speaking about H signal, it is after H blanking, and before the next H blank pulse.

    Regards.

    Alberto.

    --- Quote End ---

    Hi

    i am not sure to follow the "assign a value while the scan time is correct" part .My design is not using any .verilog (or vhdl ) file , all is done in a schematic file.

    Still for investigating , i modify the video_sync_generator.v file and redirect the output.Instead of having the output RGB_OUT connected to the data_input, , i directly assigned a constant to the output signal but i still get a black screen instead of a white screen

    Thanks
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    17 years ago

    Hi.

    Why not to add an inverter between the oVGA_BLANK_N and the RGB data, and then open them from Vcc.

    Or did you tried leaving the 9th bit of RGB data to GND instead VCC. or did you tried with only one colour ?