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Altera_Forum's avatar
Altera_Forum
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14 years ago

handling with differential signals in quartus II

Hi at all, I have a generel question about handling with differential signals in quartus II. Is it necessary to create two pins (p and n) in schematic for a differential signal or is it usual...
Altera_Forum's avatar
Altera_Forum
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14 years ago

The warning is a recent addition. Previously you only had the option of defining the 'p' pin of the differential pair, and the other pin was inferred.

You can now specify the n pin. For example, if clkin_100MHz is an LVDS signal with the p pin on A21, and the n pin on A20, you can set the p pin assignment using the signal name clkin_100MHz, and the n pin assignment using the signal name clkin_100MHz(n). You would then apply the LVDS constraint only to clkin_100MHz, not to clkin_100MHz(n).

Cheers,

Dave