( ESNUG 346 Item 15 ) -------------------------------------------- [3/16/00]
Subject: 0-in Now, And The Ethical Problems Of Kurt Baty Owning 0-in Stock
> Anders then praised 0-in's register leak check. "It found one register
> leak bug that would have been very hard to debug in the lab. It would
> have really confused our software designers."
>
> And Anders' experience was with an older version of 0-in. "I know 0-in
> has evolved since I last used it. It's apparently much easier to use now.
> It's still an interesting complement to simulation that help you find a
> class of bugs that are very difficult to find just by simulation,"
> concluded Anders.
>
> I wonder what the 0-in user experience is now. ( http://www.0-in.com )
>
> - from "A Partial 0-in Update"
From: John Andrews <john@tensilica.com>
John,
I read your description about 0-In. We're currently using a pre-release
version of the tool here at Tensilica (www.tensilica.com) so I can fill you
in on the basics of what the new tool does. The basics of their new
methodology are simple:
1) Insert 0-In checkers in your Verilog. These are assertions (in
comment form) about the correct behavior of your RTL. 0-In currently
has about 30 checkers and the library of checkers will continue to
grow. The checkers vary from extremely simple checkers (e.g. x == 3)
to complex checkers that span multiple cycle counts or that check
correct FIFO or arbiter behavior.
2) Use their CHECK tool to make sure that no checkers fire using your
simulations as stimulus. CHECK generates Verilog which you include
in your simulations along with 0-In PLI to detect if any checkers fire
during your simulation. The overhead of CHECK is pretty low. You would
typically run with CHECK during all or a large part of your regressions.
3) Use their SEARCH tool to look for stimulus different from your simulation
stimulus that causes checkers to fire. SEARCH is a formal tool that
uses your simulation input as a "seed" space to explore around. It
searches N clocks (where N is a relatively small number) around your
seed, trying to see if it can drive something other than what you drove
on the primary inputs to make a checker fire.
BTW, you can define some of your checkers as *constraints*; the rest
are SEARCH *targets*. Constraints are assertions that SEARCH will
not violate; targets are assertions that SEARCH *tries* to violate.
Typically constraints are statements about primary I/O, while targets
are internal to your design.
CHECK is just an assertion library (although I don't mind paying for a
good one, and I like theirs), so SEARCH is their main product. 0-In claims
that by using this hybrid of simulation with formal techniques, they can
deal with much larger designs than pure formal tools.
I think this flow is much different (and easier) than the one I saw in your
Industry Gadfly ("A Partial 0-in Update"). I'm pretty happy with the tool
so far, although we are just getting started doing serious work with it.
- John Andrews
TenSilica
---- ---- ---- ---- ---- ---- ----
From: Rui DosSantos <rdossantos@argon.com>
John,
Ouch. We had Kurt Baty at my place of employment pushing this tool with
disastrous results, until new management decided that enough was enough
and dumped it.
Some of us could not really figure out why he kept pushing it. Turned
out that Kurt Baty was a primary investor and technical advisor at 0-in and
that's why we were using it in the first place. We continued to use it
despite continuous setbacks even though there was a great effort by our
team to make our design 0-in friendly.
The party was over when this scam of his was finally revealed.
I don't know, neither do I care, if 0-in is better or not. We spent a lot
of time debuging the tool for them, or better yet, to safeguard Mr. Baty's
personal investment.
You're a very smart guy. A lot of people take your advice. I hope you
are not inadvertently pumping something you're not sure about. Or did
Baty put in a request himself?
- Rui DosSantos
Argon Networks Littleton, MA
---- ---- ---- ---- ---- ---- ----
From: [ Vacation Boy ]
Hi John,
I just came back from vacation watching Cactus league baseball and what do
I get? An update about 0-In ??? Yawn!!! The early employees there used
to joke about "0-in.com" said quickly sounded like "zero income" !! I am
guessing you just had a beer with Kurt Baty or something. Did you believe
http://www.techweb.com/se/directlink.cgi?EET19980601S0055 when it first
came out? Anon. Pls.
- [ Vacation Boy ]
|
|
