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Altera_Forum's avatar
Altera_Forum
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17 years ago

Internal LVDS for between-board communicatino

Hello, Suppose that I have two boards with Stratix II FPGAs. The boards sit close to each other, and lines from one FPGA reach the other, via a connector. The total length is circa 20 cm (8 inc...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
17 years ago

The answer to the typical question "how fast and how much long" is not simple. The signal frequency vs. distance issue is strictly cable-dependant, and especially varies with cable size, quality of the shield and quality of the twist for each pair.

But you are speaking of 40MHz, which is realy low speed for LVDS and you should not have any problem with 20cm. At least be sure of a good shielding of your cable and the resulting eye pattern shoul be clean enough for a correct data recovery.