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Altera_Forum's avatar
Altera_Forum
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16 years ago

(IO) EP3C40F780 differential pairs very far from each other

I see only EP3C40F780 device have differential pairs very far from each other. See in Quartus pin planner. Rest of the devices differential pairs are quite adjacent.

Attach two devices snapshots for reference.

Can I know the reason?

Appreciate if there is any help that can be provided ASAP.

Thanks

Best regards

KG Ng

2 Replies

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

    Surprizing! Seems like a strong hint not to use these devices for designs with high LVDS utilization. I have no doubts that the pin mapping is according to the documentation.

    No idea why Altera did it.
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    16 years ago

    The only answer I can find from Altera literature is for Cyclone III device package F780, 3C40 has the most IO if compare to other series. But it can not properly explain why the EP3C40F780 differential pairs very far from each other.:mad: