[myhdl-list] Re: MyHDL / ModelSim cosim

[Jan D. <ja...@ja...>]

Tom Dillon wrote:
> Jan,
> 
> I agree about the hard debugging. I did check and the docs say that the 
> functions that are used are said to be supported. I need to do some 
> simple tests to see what does and doesn't work.
> 
> I have been using icarus for the time being and it is working well.

Ok. If that's on the same machine as aldec, than that's really strange.
BTW, is aldec very expensive?

> BTW, I added signed number support to the toVerilog generation. Not sure 
> I did it the best way but so far it is working.
> 
> Also, found and fixed a problem with the Verilog signal names when two 
> similar modules are instantiated from the same module. I was getting 
> conflicting signals names. For example:
> 
> M0 = mult(x,a,b)
> M1 = mult(x1,a1,b1)
> 
> It used M0 in both cases for the base for the signal names.
> 
> Should I send you the myhdl files I have modified for your review?

Definitely - this would be a great help. (If it's easier for you,
you can just tar up a whole directory.)

I am on vacation from june 15-22, so feedback will not
be immediate.

> I have had some time the last week or so to test drive myhdl and am 
> enthused about  the possibility of combining Python with logic 
> generation and testing. So far so good.
> 
> Just figured out and started using unittests. They are great, thanks for 
> the introduction to them in the myhdl manual.

Now that you mention it :-)

I also think that unittests are a great tool that can be very useful
in hardware design, as in software. However, the emerging opinion
is that the way it's implemented in Python doesn't fully realize the
potential. It's more of a re-implementation of what exists in other
(less powerful) languages. Basically, the point is that things could
and should be much easier for a Python unit test user. I basically
agree with this viewpoint (having used unit tests a lot).

There is work going on on a powerful alternative called py.test.
I haven't checked the status recently and haven't tried it yet.
However, I know what the goal is. Creating unit tests setups would
be much less restrictive - for example, it would be perfectly possible
to simply use functions instead of (sub)classes and methods. Also,
most tests would simply be done using the Python assert statement.
This would be simpler and more powerful at the same. (For this
purpose, the treatment of 'assert' would be slightly modified from
standard Python.)

Regards, Jan

-- 
Jan Decaluwe - Resources bvba - http://jandecaluwe.com
Losbergenlaan 16, B-3010 Leuven, Belgium
     Using Python as a hardware description language:
     http://jandecaluwe.com/Tools/MyHDL/Overview.html