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Altera_Forum's avatar
Altera_Forum
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14 years ago

pin assignment

hi:

In order to draw a PCB which contains BGA chip (FPGA)conveniently,I want to assigned pin manually in the quartusII,so I can check the correctness of my assignment thougth quartusII compilation.

after compilation,there is no error about assignment ,but there is a critical warning,that is :"timing requirments for slow model timing analysis were not met ".

I want to know if or not the problem of timing waring need to overlook ?

and there is another questions:

Besides pin assignment maunally,is there any better way to assign pins,expecialy for BGA packaging?

12 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    --- Quote Start ---

    hi:

    In order to draw a PCB which contains BGA chip (FPGA)conveniently,I want to assigned pin manually in the quartusII,so I can check the correctness of my assignment thougth quartusII compilation.

    after compilation,there is no error about assignment ,but there is a critical warning,that is :"timing requirments for slow model timing analysis were not met ".

    I want to know if or not the problem of timing waring need to overlook ?

    and there is another questions:

    Besides pin assignment maunally,is there any better way to assign pins,expecialy for BGA packaging?

    --- Quote End ---

    Hi,

    the warning means that your design did not run with the required clock speed. If you did not define a clock requirement Quartus ( TimeQuest) assumes a clock frequency of 1 GHz,

    which is normally not a realistic requirement.

    Kind regards

    GPK
  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    I am sorry for posting questions twice times!~

    hi:

    pletz,thanks for your reply~

    the system clock is 50MHz,which is far less than 1GHz,it is a realistic requirement.so I wanna know what I should do to resolve the problem,dose it have relation with pin assignment?
  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    Maybe you can create pin assignment and then import into your project.

  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    your mean is that making a .qsf or .csv file,and import the file in QuartusII,it is the way to assign pin.but I want to ask how to judge the pin assignment is right,maybe some pin cannot be assigned,but I assign it.now,I can only judge the correction by QuartusII complilation,if there is no error about pin assignment,it will be right?

  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    I think you are working on an evaluation board, right? Is there any information from the manual?

  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    Maybe our tools are different. But I am using terasic DE2-115, and there is a tool in the manual CD which can assign pins correctly and create a csv to import.

  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    I want to design PCB board by myself,so the pin assignment should be changed,so the .CSV is different from the DE2 board ,for example :clk_50 ,change the pin assignment from PIN_N2 to PIN_N1.

    so I should make sure the assignment changed is right.how to realize it ?
  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    In one way or another, you have to do the pin assignment manually.

    Some EDA tools have options to allow you to change the pin assignment directly in the tool, which makes it easier to change the pin assignment to simplify board design.

    But in the end, before sending the PCB to production, you always need to

    a) compile the design in Quartus and see if there are pin assignment errors

    b) check you board against the .pin report file produced by Quartus

    c) check your board against the pin assignment guidelines

    That TimeQuest error is not a concern for pin assignment.
  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    --- Quote Start ---

    I want to design PCB board by myself,so the pin assignment should be changed,so the .CSV is different from the DE2 board ,for example :clk_50 ,change the pin assignment from PIN_N2 to PIN_N1.

    so I should make sure the assignment changed is right.how to realize it ?

    --- Quote End ---

    rbugalho is absolutely right. Specifically, it is not recommended to change the pin if you are not familiar with the FPGA pins. But if you really want to do, you have to search for appropriate instructions about pin configuration. An example I just found is for cyclone III, the link is http://www.altera.com/literature/an/an466.pdf

    You will find "Board Design Considerations" from page 17.