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Altera_Forum's avatar
Altera_Forum
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11 years ago

Cyclone iii developpment board: DVI problem

Hello all,

I create a Sopc system to test my dvi output but it does'nt work. I use a test pattern and a clocked video output, it's a simple system. I use a clock of 108Mhz for a resolution of 1920*1080. what can I do to have a picture in my screen?

Cordially

3 Replies

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

    Where did you get your timing specs for the DVI output? The pixel clock for 1920x1080 @ 60 fps (1080p) is 148.5MHz, not 108MHz. You also have to make sure the horizontal and vertical sync timing and polarity is correct.

    What is between the FPGA and the DVI output? terasIC DVI-HSMC card? Are you asserting DE to the card correctly?
  • Altera_Forum's avatar
    Altera_Forum
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    11 years ago

    --- Quote Start ---

    Where did you get your timing specs for the DVI output? The pixel clock for 1920x1080 @ 60 fps (1080p) is 148.5MHz, not 108MHz. You also have to make sure the horizontal and vertical sync timing and polarity is correct.

    What is between the FPGA and the DVI output? terasIC DVI-HSMC card? Are you asserting DE to the card correctly?

    --- Quote End ---

    Yes thank you, it's 148.5 Mhz. for tha used card it's DVI-HSMC. I just want to make a transmission of an image and display it using DVI. I am using SOPC to create my system:

    - Clock

    -Clocked video input

    -DDR2

    -clocked video output

    But it still doesn't work.

    Cordially.
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    11 years ago

    In your first post you said you're trying to output a test pattern. Is that test pattern coming in your video in port and through DDR2? If so, then break things up. Drive a test pattern directly out the DVI output and play with that until it works. No point using the video in port and DDR2 memory if you can't get the output port to work.

    I'll ask again about the output timing. What are your front porch, sync width, back porch and polarity settings for HSYNC and VSYNC? How many total video lines are you putting out and how many total pixel clock cycles per video line? All of that plus the pixel clock frequency have to be correct.

    Do you know how to use SignalTap? If no, then learn. Have you simulated your design? If not, then learn how to do that as well. Debugging by staring at a blank display is not going to get you very far. I don't mean to be disrespectful, but you don't seem to be trying very hard here.