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VTC control From ZedBoard HDMI VIPP, Vivado 2014.1 Tutorial

Former Member

Hello,

I am trying to modify the ZedBoard HDMI VIPP, Vivado 2014.1 Tutorial to output 480P, instead of the 1080P that comes as part of the tutorial.(Note I have ported it to Vivado 2104.2)

I have debugged the code and added debug lines in vhdl so that I can see vsync and hysnc lines between VTC, v_axi4s_vid_out and zed_hdmi_out blocks on an oscilloscope.

Everything is as expected with 1080P, but when the code writes 480P or any other video resolution for that matter the VTC does not put anything out on vysnc or hysnc or de?

Does anyone have example code to write resolutions apart from 1080P using the VTC? I am struggling to see why the VTC just doesn't do as its told?

All help greatly received!

Stephen

  • 0

    Stephen,

    The display controller tutorial targets 1080P60 resolution.  This involves two important aspects:

    1) pixel clock (or video clock)

    2) video timing configuration

    By default, the design generates a static pixel clock of 148.5MHz for the 1080P60 resolution.

    If you want to target a different resolution, you need to change the pixel clock frequency accordingly.

    If you need to support several video resolutions, then you will need to add the ability to change the pixel clock's frequency, which is not supported by this tutorial design.

    Regards,

    Mario.

  • 0 in reply to albertabeef

    Hi Mario,

    Thanks for that information, I had wondered about the pixel clock but had half dismissed it because I couldn't find anything in the VTC documentation which said the Video Core Clock had to be with certain limits for certain video resolutions. Also whilst I wasn't neccesarily expecting to see the correct vsync/hsync timings, I was expecting see some sort of signal on the sync lines. Hence when I saw nothing I started scratching my head.

    Can you advise of a good tutorial that does support several video resolutions?

    Lastly, do you know how to run/generate the test bench design for the VTC? I'm failing at that too.

    Many, many thanks for your help!