Re: [myhdl-list] functional verification

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

Jacob Rael wrote:
> Hello all,
> 
> I ran across myhdl when I first started learning Python and it looked
> really interesting.
> 
> I am currently looking at how to do functional verification on our
> designs. We are a mixed signal group and we deal with analog signals
> at ports. Many of the HVL tools available assume only digital signals
> so I am expanding my search beyond specman.

Currently it's the same for MyHDL.

> I like myhdl because it is Python based and I can see an easy path
> from design verification based on simulation to chip verification
> based on lab tests all within the same Python environment.
> 
> I started looking at the Ruby tool, Ruby-vpi. On the surface, it looks
> like it can do everything I want to do but I have not dived down into
> the details. Also, I don't want to learn a new language.

Does Ruby-vpi support analog signals then?

> So, I have a few questions:
> 
> 1. Our main simulator is ncsim. From the little I have read, I would
> have to write a C-program to allow myhdl to talk via PLI to ncsim. Has
> this already been written? What about other commercial simulators?

There is support out-of-the box for Icarus and cver. Look in the cosimulation
dir in the distro and in the manual. As PLI is supposed to be a standard,
these C modules should work with other simulators - in practice adaptations
may be necessary.

I know people have used this with commercial simulators in the past
(also with ncsim I believe).

> 2. Is there any limitation in myhdl (or PLI) that would prevent analog
> (wreal or electrical) signals from traveling in and out of ports?

It's not supported in the MyHDL cosimulation modules currently.
I assume there's no restriction in PLI but I haven't considered this.

> 4. How active is the development on myhdl? The main Google links give
> the impression there isn't much going on. I didn't discover the posts
> on the newsgroups or the new site until I started digging deeper. I am
> glad I saw recent posts. At first I thought the project had been
> stagnant since version 0.5.1.

As for as I'm concerned, thinking goes on continuously but development
occurs in bursts, driven by time availability and external interest.

On sourceforge, I only release "official" releases, but on the MyHDL
website, development snaphots can be found.

Jan

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