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Altera_Forum's avatar
Altera_Forum
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14 years ago

Stratix III LVDS cross connect

(Ignoring logic polarity issues) Is it electrically valid to cross connect LVDS signals between Stratix III FPGAs? The reason for doing this is that we made a piggy back modification board to add some missing connections and because the board is single sided we can only cross- connect the LVDS pairs i.e. TX(p) to RX(n) and TX(n) to RX(p).

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  • Altera_Forum's avatar
    Altera_Forum
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    --- Quote Start ---

    (Ignoring logic polarity issues) Is it electrically valid to cross connect LVDS signals between Stratix III FPGAs? The reason for doing this is that we made a piggy back modification board to add some missing connections and because the board is single sided we can only cross- connect the LVDS pairs i.e. TX(p) to RX(n) and TX(n) to RX(p).

    --- Quote End ---

    Yes this is electrically valid. You should length match the p/n traces for each differential pair.

    Cheers,

    Dave
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor

    Great, many thanks. I assumed it was and couldn't think of any reason it wouldn't be but nice to have confirmation!