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Altera_Forum's avatar
Altera_Forum
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15 years ago

How to confirm pin assignment for a cyclone chip with LVDS, SSTLII, 2.5v LVCMOS I/O?

Hi All,

I'm designing a FPGA project with cycloneIII.

Since we have to use LVDS input together with DDR(SSTLII classI) and 2.5v LVCMOS voltage level I/O. the minimum pin distance between LVDS and 2.5v LVCMOS must be guaranteed. So I create a vacant module with all I/Os instantiated.

My question is, is that ture that only if the compilaton can successfully pass that means the I/O assignment is ok?

Anyone who have similar experience can give out some advice?

Thanks !

2 Replies

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

    --- Quote Start ---

    My question is, is that ture that only if the compilaton can successfully pass that means the I/O assignment is ok?

    --- Quote End ---

    If compilation includes fitter process then yes, it is true.

    A little tip: you can configure Quartus to check I/O assignments validity before full compilation is initiated. Go to Assignments->Settings->Compilation Process Settings and check "Run I/O assignment analysis before compilation". Or you can run this check directly from Processing->Start menu.