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Altera_Forum's avatar
Altera_Forum
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16 years ago

How to process this warning?!

Hi Dears:

I got below warning after compiling:

"Warning: Found 43 output pins without output pin load capacitance assignment"

My question is that how to assign this assignment? What function of this assignment? And I can see some informations following this warning is below:

" Info: Pin "FPGA_OE" has no specified output pin load capacitance -- assuming default load capacitance of 0 pF for timing analysis"

Is it mean that the QII would assign with a default value and we can ignore this warning?

2 Replies

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

    --- Quote Start ---

    Hi Dears:

    I got below warning after compiling:

    "Warning: Found 43 output pins without output pin load capacitance assignment"

    My question is that how to assign this assignment? What function of this assignment? And I can see some informations following this warning is below:

    " Info: Pin "FPGA_OE" has no specified output pin load capacitance -- assuming default load capacitance of 0 pF for timing analysis"

    Is it mean that the QII would assign with a default value and we can ignore this warning?

    --- Quote End ---

    Hi Jerry,

    the assignment would enhance the precision of the timing analysis. As long as you are not working on a highspeed interface like DDR2/DDR3 you can ignore the warning at the beginning. If you have this information ( maybe from your PCB tool) you can set this assignment in the Assignment Editor ( Ouput pin load). The Quartus deflaut value is 0 pF.

    Kind regards

    GPK