Changing generics in top-level module

Discussion in 'VHDL' started by Martin Thompson, May 25, 2004.

  1. Hi all,

    Is there a way of changing the generics of the top-level entity from a
    configuration?

    My testbench has some parameters I'd like to tweak on different runs,
    and I would like to do it via multiple configurations, rather than
    vsim options. However, I can't figure out how to do it!

    My current solution involves instantiating this top level testbench in
    an even higher level entity, which I can then use configurations on,
    but this seems wasteful...

    Any suggestions greatly appreciated!

    Thanks,
    Martin

    --

    TRW Conekt, Solihull, UK
    http://www.trw.com/conekt
     
    Martin Thompson, May 25, 2004
    #1
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  2. Not yet, there is a proposal on this, see
    http://www.eda.org/vhdl-200x/vhdl-200x-ft/proposals/proposals.html (FT23)
    Egbert Molenkamp


    "Martin Thompson" <> wrote in message
    news:...
    > Hi all,
    >
    > Is there a way of changing the generics of the top-level entity from a
    > configuration?
    >
    > My testbench has some parameters I'd like to tweak on different runs,
    > and I would like to do it via multiple configurations, rather than
    > vsim options. However, I can't figure out how to do it!
    >
    > My current solution involves instantiating this top level testbench in
    > an even higher level entity, which I can then use configurations on,
    > but this seems wasteful...
    >
    > Any suggestions greatly appreciated!
    >
    > Thanks,
    > Martin
    >
    > --
    >
    > TRW Conekt, Solihull, UK
    > http://www.trw.com/conekt
    >
    >
     
    Egbert Molenkamp, May 26, 2004
    #2
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  3. Martin Thompson

    Alan Fitch Guest

    "Martin Thompson" <> wrote in message
    news:...
    > Hi all,
    >
    > Is there a way of changing the generics of the top-level entity from

    a
    > configuration?
    >
    > My testbench has some parameters I'd like to tweak on different

    runs,
    > and I would like to do it via multiple configurations, rather than
    > vsim options. However, I can't figure out how to do it!
    >
    > My current solution involves instantiating this top level testbench

    in
    > an even higher level entity, which I can then use configurations on,
    > but this seems wasteful...
    >
    > Any suggestions greatly appreciated!
    >


    As Egbert says, not yet. In the current VHDL LRM it says that a
    particular
    implementation of the language is not required to support ports and
    generics
    on a top level entity, though it may.

    Using a wrapper (or donut as the Americans say) is one approach, as
    you've
    taken.

    You can sometimes use simulator features, for instance vsim -g in
    modelsim.
    You could then write a set of scripts to launch simulation runs with
    different
    top level generics. Of course this isn't as portable as using a
    wrapper.

    regards

    Alan


    --
    Alan Fitch
    Consultant

    DOULOS - Developing Design Know-how
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    Doulos Ltd. Church Hatch, 22 Market Place, Ringwood, Hampshire, BH24
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    The contents of this message may contain personal views which are not
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    views of Doulos Ltd., unless specifically stated.
     
    Alan Fitch, May 26, 2004
    #3
  4. Thanks for those inputs - looks like a wrapper for now then.

    Cheers,
    Martin

    --

    TRW Conekt, Solihull, UK
    http://www.trw.com/conekt
     
    Martin Thompson, May 26, 2004
    #4
  5. Martin Thompson

    Jim Lewis Guest

    The latest is that this proposal has been demoted
    to the MP list. I will be updating the reflector
    to indicate this shortly.

    How much we get done and how fast we can do it
    is really a function of participation. Hint. Hint.
    Hint. Observer participants (no membership required)
    with a good knowledge of the VHDL LRM are welcome
    to write an LCS (Language Change Specification).

    Things get worked on based on priority and based on
    someone being willing and having the time to write
    an LCS. This item rolled off the fast track list
    due to priority, required delivery schedule for
    fast track items (must have an LCS by DAC), and
    not enough bandwidth from the current members (we
    tend to take time off to sleep, say hi to the wife,
    and play with the kids). It is a volunteer effort,
    so for most it means our job does not pay us to do
    the work.

    Cheers,
    Jim
    --
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    Jim Lewis
    Director of Training mailto:
    SynthWorks Design Inc. http://www.SynthWorks.com
    1-503-590-4787

    Expert VHDL Training for Hardware Design and Verification
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    > Not yet, there is a proposal on this, see
    > http://www.eda.org/vhdl-200x/vhdl-200x-ft/proposals/proposals.html (FT23)
    > Egbert Molenkamp
    >
    >
    > "Martin Thompson" <> wrote in message
    > news:...
    >
    >>Hi all,
    >>
    >>Is there a way of changing the generics of the top-level entity from a
    >>configuration?
    >>
    >>My testbench has some parameters I'd like to tweak on different runs,
    >>and I would like to do it via multiple configurations, rather than
    >>vsim options. However, I can't figure out how to do it!
    >>
    >>My current solution involves instantiating this top level testbench in
    >>an even higher level entity, which I can then use configurations on,
    >>but this seems wasteful...
    >>
    >>Any suggestions greatly appreciated!
    >>
    >>Thanks,
    >>Martin
    >>
    >>--
    >>
    >>TRW Conekt, Solihull, UK
    >>http://www.trw.com/conekt
     
    Jim Lewis, May 26, 2004
    #5
  6. Hi Martin,

    I know that configuration isn't supported for RTL synthesis
    (IEEE-1076.6-1999), but have you try to change your generics via the
    configuration binding ?

    I remember you that in IEEE-1076-2002, chapter 5.2, the configuration
    specification can include some aspect of generic_map_aspect (see section
    2.5.1).

    I don't know how simulator implement it, but that can be your solution.

    JaI

    Martin Thompson wrote:

    >Hi all,
    >
    >Is there a way of changing the generics of the top-level entity from a
    >configuration?
    >
    >My testbench has some parameters I'd like to tweak on different runs,
    >and I would like to do it via multiple configurations, rather than
    >vsim options. However, I can't figure out how to do it!
    >
    >My current solution involves instantiating this top level testbench in
    >an even higher level entity, which I can then use configurations on,
    >but this seems wasteful...
    >
    >Any suggestions greatly appreciated!
    >
    >Thanks,
    >Martin
    >
    >
    >
     
    Just an Illusion, Jun 8, 2004
    #6
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