Re: [myhdl-list] VHDL Cosim Initial Thoughts

[Christopher F. <chr...@gm...>]

On 1/13/13 3:26 PM, Daryl Wasden wrote:
> Christopher Felton <chris.felton <at> gmail.com> writes:
>
>>
>> On 1/8/13 6:30 PM, Daryl Wasden wrote:
>>>>>> Also, I haven't yet figured out how to deal with delays...
>>>>> I am not sure what you are asking or not understanding
>>>>> here?
>>> I see how this works now. I didn't completely understand the
>>> format. Now, I see the protocol structure. The time is sent
>>> first, then any signal changes. Doing the socket-based
>>> cosimulation in verilog was helpful.
>>>
>>> I am still fixing one bug, but the simulation is running
>>> correctly using socket communication on windows. I ran
>>> the test_bin2gray using Icarus. The bug is related to
>>> reusing the same port when moving between tests... If I
>>> get this up and running and fix the bug, then I'll work
>>> on porting it over to Linux/Mac OSX as well.
>>>
>>> -Daryl
>>>
>>>
>>
>> Sounds like you are making good progress.  If you want, we
>> can setup a bitbucket repository and I can test out your
>> changes as well.  I don't have a windows system right now
>> but I can test it out on a linux.
>>
>> Regards,
>> Chris
>>
>>
>
> Sure, that would be great. My free time is going away quickly,
> but I should be able to put in at least a few hours every week.
> With where I am now, that should still get things done
> relatively fast. Currently, the simulation runs okay, but
> if you try to execute two simulations quickly, there can be
> a problem because ports don't register as closed immediately
> after you close them. Also, it only works on localhost
> right now because of how it is designed... This wouldn't be
> too difficult to change, but it would require the user to
> start the process on the server manually prior to starting
> the MyHDL simulation which deviates from the current
> implementation, but may be useful for me later. So, I'll
> look into that as well at some point.
>
> I've never used bit bucket before, but I will look into it.
> Should I email you personally when I've got everything up or
> just keep posting to the mailing list? Also, should I put
> the 0.8dev code up there and contribute to it or just
> include the subclassed code and the (modified) test code?

You can create a repository and push your changes or I
created a repository on bitbucket.  If you want to use
the clone I created:

https://bitbucket.org/cfelton/myhdl_vhdl_cosim/overview

The following should get you started.

    >> hg clone https://bitbucket.org/cfelton/myhdl_vhdl_cosim
       <local_path>
    # Add a <user>@bitbucket.org if you want to push later
    # after cloned the bitbucket clone of myhdl, push your changes
    >> cd <to your current working >
    >> hg commit # commit any modifications
    >> hg push <path to your local clone, first command above>

You will need to create a bitbucket user and then you can push,
bitbucket is essentially the same as github just mercurial
based and not git.

The conversation can continue on this mailing-list unless
anyone else objects.  The feedback from other users/devs
can be very useful.

>
> The one problem is that this method (or any method other than
> the one provided in the present version) requires a change
> to _Simulation.py as well because the Cosimulation pipes are
> closed by the Simulation class methods manually and not by a
> call to the Cosimulation class methods. This would be easily
> changed, but I'm not sure how to suggest such a patch. I
> looked on the website and it says to send ideas to the mailing
> list for discussion. I put it in an earlier reply on this
> thread, but maybe I should make a new thread and put it there?

Yes, a new thread with this specific issue.

>
> I'm sorry for all my questions, I'm trying to figure out the
> proper etiquette for contributing to the project still. The
> modification would not change any existing behavior, it would
> just make it possible to subclass the Cosimulation object and
> use other methods for inter-process communication. At some
> point, I think I'll look into putting windows pipes.

Questions are perfect!  Jan D. has outlined how to communicate
changes and commit bundles (patches).

http://www.myhdl.org/doku.php/dev:patches

>
> Also, the class CosimulationWithSockets is based heavily on
> the original Cosimulation class with the only changes being
> initialization, communication, and clean up of the sockets
> (instead of the pipes) and the use of the multiprocessing
> module to generate a child process instead of os.fork().
> I should include the original license at the top of the
> file in this case, correct?
>
> Thanks again, I really appreciate you helping me to
> understand these things. I know that you are busy, too...
>
> -Daryl
>

No problem, these two topics are asked once in a while,
VHDL cosimulation and windows cosimulation.  I think
their are others that might be interested as well but
probably don't have the cycles right now.

Regards,
Chris