[myhdl-list] Re: Cosimulation with the simple FSM example.

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

George Pantazopoulos wrote:

> Yeah, I think I will try that. Also, I want to try making it easier to do
> co-simulation/unit testing. I'm doing my project for fun, and often I feel
> it hampers the fun and creativity if I have to write up (and debug!) a
> unit test every time I add or change a component.

I understand completely. We're engineers, and we want results asap.

I think the expected lifetime of your project is important. Take
my case with MyHDL itself for example. I knew that it would be a
long-going project and that sometimes I may not touch it for months.
What unit tests give me is that I have at least a basic level of
confidence to change things (perhaps after a long period
of inactivity). Without them, the project would be one big mess by now,
I'm sure. While I am writing unit tests, they often seem trivial,
or overhead, but they really are not. On numerous occasions, they
have prevented me from creating new or re-creating old bugs.

Note that I'm also using the XP technique of first writing the test,
see it fail, and then add or adapt the implementation to make it
work. This is fun and enhances confidence.

Often we tend to underestimate the lifetime of a project (this may be
your case :-)) In such cases, under-verification creates uncertainties
and bugs that will hamper productiviy in the longer run. Your decision
not to use enum types may be an example :-)

> I feel my last attempt at incorporating unit testing in my design flow was
> somewhat successful, however I really didn't like having to spend time
> debugging the unit tests themselves! This may be easier now that I'm more
> experienced with Python, myHDL, co-simulation, and hardware design (that's
> a lot of things to learn at once, on top of extreme programming!). Unit
> testing and co-simulating *everything* still doesn't feel natural to me,
> and I'm not sure if it ever will.
> 
> Speaking of promotional breaks, have you seen the new colorful photos I
> took of my project? :-)
> 
> http://myhdl.jandecaluwe.com/doku.php/projects:phoenixsid_65x81

Sure, thanks for those. They convincingly illustrate that MyHDL
is a practical tool that can be used for real engineering projects.
Which is exactly what I want it to be.

Jan

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Jan Decaluwe - Resources bvba - http://www.jandecaluwe.com
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