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Altera_Forum's avatar
Altera_Forum
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16 years ago

DVI Tx in Cyclone III

Hi there,

I'm going to do a prestudy about the DVI/HDMI interface. There is a lot of questions. Perhaps someone could give me some answers?

1. Q: Is it possible to implement a DVI Tx in a Cyclone III FPGA?

If not, Is there any Altera FPGA device supporting this?

2. Q: Is there any application notes/white papers regarding this?

3. Q: Is there any DK-boards available for DVI/HDMI?

I'm not looking for DK:s with external DVI/HDMI driver circuits,

I want to implement it in a FPGA.

Thank You!

7 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    16 years ago

    Xilinx used to have a DVI implementation for the spartan 3. You might be able to find it. And I know Lattice has a DVI demo for their EPC2 and EPC3 devices.

    Jake
  • Altera_Forum's avatar
    Altera_Forum
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    16 years ago

    the Altera devkits I've seen have HDMI driver chips, i'm not sure if there are any driving video straight from I/O.

  • Altera_Forum's avatar
    Altera_Forum
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    16 years ago

    The Vcc terminated CML is an unique feature of the DVI physical layer. At lower rates, it can be driven from FPGA I/Os with series termination resistors. But DVI requires bit rates up to 1.65 Gbps, that can't be achieved by Altera High-Speed Differential I/O Interfaces (Stratix IV can achieve 1.6 Gbps, apart from the need for LVDS to CML level conversion). GX transmitters can easily handle the higher rates but can't provide low DVI speeds down to 250 Mbps.

    I don't expect, that this situation is basically different with other vendors. So using dedicated external DVI serializers/TMDS drivers seems an easy solution.
  • Altera_Forum's avatar
    Altera_Forum
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    16 years ago

    Yes, I agree that a external driver should be easyer. Why I ask is because our board today gives an FPGA driven LVDS output and the PCB area we have could not space a external driver circuit. Well, so then we have to create som kind of daughter card then. Another question: If we want to by a oscilloscope to measure on DVI signals, what is the recomended crieria for such a equipment?

    /Blomman
  • Altera_Forum's avatar
    Altera_Forum
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    16 years ago

    If you are looking for an oscope to look at DVI signals, it won't be cheap. If you are using lower video resolutions, you could get by with a less expensive scope. Take the maximum bandwidth of your signal and multiple it by 2x. Look for scope with this bandwidth. The DVI runs at 10 bits per clock, at a pixel clock of 100 Mhz, the data rate is actual 1GHz. I would prefer at least a 2Ghz scope.