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Altera_Forum's avatar
Altera_Forum
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11 years ago

Qsys project re-generate issue(PCIe in Qsys for StratixIVGX)

Hi guys,

I just download the example project(PCIe in Qsys for StratixIVGX) from wiki, and open Qsys to generate it again, I didn't change anything. However, i got this errors

http://www.alteraforum.com/forum/attachment.php?attachmentid=9824&stc=1

It seems powerdown signal in primary project is float, these error tell me to export this signal outside Qsys and connect to somewhere. My QII version is 12.1+sp1. My question is why this happens when i re-generate?

4 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    This is simple:

    As the error already says: Export them!

    To put it quick: if you do not use a port in QSYS, export it to the "Outside". There you can connect it to Ground, Vcc or other logic.

    For the powerdown-ports especially you can invert the PCIe_reset_n and use it as Input to powerdown. As I know this is also the way it's done in the Altera design example.

    PS: for good digital design: EVERY input has to be connected to something. For example if you don't use some Inputs of an OR-Gate, wire them to ground. If you don't use some Inputs of an AND-Gate, wire them to Vcc. Inputs which are "dangling in the Air" produces unexpected behaviour.
  • Altera_Forum's avatar
    Altera_Forum
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    --- Quote Start ---

    This is simple:

    As the error already says: Export them!

    To put it quick: if you do not use a port in QSYS, export it to the "Outside". There you can connect it to Ground, Vcc or other logic.

    For the powerdown-ports especially you can invert the PCIe_reset_n and use it as Input to powerdown. As I know this is also the way it's done in the Altera design example.

    PS: for good digital design: EVERY input has to be connected to something. For example if you don't use some Inputs of an OR-Gate, wire them to ground. If you don't use some Inputs of an AND-Gate, wire them to Vcc. Inputs which are "dangling in the Air" produces unexpected behaviour.

    --- Quote End ---

    Hi Steffen,

    Thanks for you reply, it's OK now! The next step is to add my own fifo inside Qsys.
  • Altera_Forum's avatar
    Altera_Forum
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    I've made a screenshot of my exported ports of PCIe outside of QSYS.

  • Altera_Forum's avatar
    Altera_Forum
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    --- Quote Start ---

    I've made a screenshot of my exported ports of PCIe outside of QSYS.

    --- Quote End ---

    I got it, thank you very much.