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  1. #1
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    Generating multiple HDMI outputs with FPGA

    Hi! I'm currently trying to do a big (at least for me since I'm kind of new to de FPGA world) project but before I even start I want to know if it's even possible.
    I'm thinking of being able to generate multiple (from 2 to how many as possible) HDMI outputs out of a FPGA (I have a Cyclone IV), maybe at first just displaying plain colors on multiple monitors.
    My board doesn't have HDMI outputs but I'm thinking about making a sort of expansion board of my own with the HDMI connectors and other IC's if necessary.
    1) Is it possible?
    2) Has it been done? Or somewhere to get some info about this subject?
    3) Do I need to use any IC's between the FPGA and the outputs?

    Thanks!

    •   Alt1st January 2018, 15:26

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  2. #2
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    Re: Generating multiple HDMI outputs with FPGA

    HDMI is a high speed interface that uses TMDS signal levels - simply using an expansion board with FPGA IOs may not work.
    What board are you using ?



    •   Alt1st January 2018, 21:43

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  3. #3
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    Re: Generating multiple HDMI outputs with FPGA

    I'm using a cheap chinese board with a Altera Cyclone IV that doesn't have any HDMI connectors on it (because well, thats what I can afford haha).
    I'm thinking maybe designing my own board from 0 and taking the chip from the board I have currently, I know it may be really difficult to get done but I'm studying electronic engineering and even thought I'm not actually capable of designing a high end board yet I think that trying to accomplish this will teach me a lot about digital signals board design even if it doesn't work.
    I've seen some videos of people doing similar things with homemade expansions boards like this one:
    https://www.youtube.com/watch?v=urU9bo1LpwY
    Is there any code example for generating/handling these TMDS signals so I can have an idea of how to do it?
    Here's a photo of the board I have:
    Attachment 143670

    Thanks!



    •   Alt2nd January 2018, 00:26

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  4. #4
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    Re: Generating multiple HDMI outputs with FPGA

    I really don't mean to discourage you - but when I'm learning something new, I try to keep to a minimum the number of "things that can go wrong". This way, finding the reason why the LED doesn't blink becomes a problem of ~1,000 variables instead of ~10,000,000 variables...

    This is a nice place for newbies to start learning about HDMI:
    http://www.fpga4fun.com/HDMI.html

    This may also be interesting to you:
    https://www.xilinx.com/support/docum..._Interface.pdf


    Designing the whole HDMI core with the 8b/10b encoding will probably take a year if it's your first project.
    It will be much easier to either use a vendor IP (which I doubt the Cyclone IV supports)

    Or a separate IC that the FPGA will talk to via a parallel bus
    http://www.ti.com/interface/hdmi-dvi.../products.html

    Again,
    I STONGLY suggest you get a good evaluation board with all the peripherals you need.



  5. #5
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    Re: Generating multiple HDMI outputs with FPGA

    The are two easy possible solutions:
    - use dedicated chip from Analog Devices like ADV7513
    - try to use buit-in hardware, here is some reading about generation of HDMI from DE0-nano board: https://sites.google.com/site/ece312.../hdmi_de0-nano



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