[myhdl-list] MEP 107 need for portmap

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

Previously, we had a short discussion that the MEP107
interface conversion for top-levels (e.g modules being
converted) introduced a need for a generated /portmap/ [1].

The main uses case, given a module:

     def m_some_mod(ifc1, ifc2):
         # ...

If I am verifying the above module via co-simulation,
without a /portmap/ I would need to manually write a
wrapper or manually breakout all the interface /Signals/
when building the /Cosimulation/, example:

     Cosimualation(simcmd, ifc1_di=ifc1.di, ifc1_do=ifc1.do ...

In this case it defeats the purpose of the interfaces.
To address this complication Keerthan proposed a /portmap/
be generated in the conversion functions, the above would
then become:

     Cosimulation(simcmd, **portmap)

Ahhh, much better :)

The /toV*/ functions already return a list generators in
the module.  The /portmap/ can't be returned from the
/toV*/ functions without breaking backwards compatibility.

The current proposal is to attach a function attribute to the
/toV*/ functions, e.g:

     toVerilog.portmap

The /toV*.portmap/ would be the dictionary of the converted
portmap (interface expanded names).

I would like to propose and discuss attaching the /portmap/
attribute to the function being converted and not the
conversion functions.  To me this is a more natural (I don't
know if this is generally pythonic (accepted) to have other
functions modify and/or add attributes to other functions).

In addition, I would propose that generated portmap saved
in the /vportmap/ attribute and the /portmap/ attribute
to be used as a user defined default port definition.

Keerthan has done an amazing job implementing MEP-107, many
thanks!  He has also created a pull-request for the
/toVerilog.portmap/, I wanted to have a short discussion
and make sure this is the most flexible path moving forward.
Once we finalize the portmap I can update the MEP.

Regards,
Chris

[1] http://thread.gmane.org/gmane.comp.python.myhdl/3223/focus=3318