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Altera_Forum's avatar
Altera_Forum
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19 years ago

How to use LVDS?

in datasheet,i find maybe it isn't similar to use LVDS in Cyclone1,cyclone2,and cyclone3,

so what can i do if i want to use LVDS?

1,does it need resistor?

2,how many wire i need ?

in my opinion there is two way to do this

the one is two wire and use CDR,

and the other is four wire use two to send data ,and two as clock reference.

can you tell me the trues?

thank u

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

    in my opinion,it will not damage chips.

    and in datasheet the long u use the speed will go slowly.

    U can try it.

    good luck!

    and i want to ask u how many wire do you use ?
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    19 years ago

    Hello stephenzhou. Yes, you should use external resistors in Altera and Xilinx.

    I'm going to use LVDS too. And I have some questions. I have a devboard from Atmel with LVDS outputs and I want connect it with my Cyclone board. In datasheet I have read, that Atmel board has 100 Ohm termination resistors. So I can connect it directly to Cyclone pins. But distance between resistors and Cyclone device is very long( much longer, than recomend Altera). Will be it work? Can it damage chips?