RE: gEDA: Re: Results from verilog XL

[stevew <stevew-at-NOSPAMhome_dot_com>]

Verilint IS the product I'm most familiar with and I believe there are
some others.  Uhm - it's NOW a two edged sword (things change 
very fast in this industry ;-)

I've found that recent versions of Verilint are extremely useful for a couple
reasons. They tend to worry not JUST about "correct" Verilog, but also 
poorly coded verilog, and verilog that won't synthesize!  

Some examples:

Verilint will complain about something like:
    reg [7:0] newval, oldval;

     always @(posedge clk)
            newval <= oldval + 1;
    or      newval <= oldval + 8'b1;

It doesn't like the fact that you haven't spelled out all the bits of the
constant.  It'll also complain about EVERY case statement - you either
forgot the default clause or you have an incomplete case, i.e. not all
possible casses specified but have a default...both cause warnings ;-)
The ONLY way to get it not to give you a warning with a case statement
is to have a fully specified case statement WITH a default...sheesh ;-)

It's an Overly pedantic tool - but probably what you want!

The single BIGGEST use I'd find for the tool is to check out your code before
you would tie up the $20KVerilog simulator!  This can be REAL important when
all you have is 3 or 4 verilog licenses and 15 designers. 

The other side of the sword turned up just a couple days ago. I found out that
Interhdl has been purchased by Avanti, and that the price is now something like
$47K - So you use the $47K tool to save use of the $20K tool - that seems a bit
backwards?  Many suspect that Avanti is trying to kill off the tool and move
it's users to their "Development Environment."  

SO - because of the synthesis aspect - and the requirement to gripe even
about legal code - you want something that is stricter than a compiler that
just accepts legal verilog.

Steve

On Wed, 16 Jun 1999, you wrote:
>David Cary writes:
>
> > Steven Wilson seems to be saying tools "are available for this sort
> > of thing", but I'm a little confused. Are there really Lint-like
> > tools available for checking Verilog code ? Do these tools have a
> > name, or a manufacturer ?
>
>i've heard of verilint.  it and its ilk were not impressive when i
>evaluated them (about five years ago), but perhaps things are better
>now.
>
>most eda vendors bundle a token linter, probably all kludged from the
>same original buggy source (licensed from "interhdl"?)...
>
>thi