( ESNUG 297 Item 1 ) ---------------------------------------------- [7/30/98]
Subject: (ESNUG 295 #12 296 #1) VERA vs. Specman: VERA Is A Subset Of Specman
> I am open to compare specific features of SpecMAN and VERA if theres an
> SpecMAN expert out there who is willing to have a friendly comparison.
>
> [ Long, Detailed Technical Description Of VERA Snipped ]
>
> I just like VERA and hope it will continue to grow. ...
>
> - Rudolf Usselmann, Consultant
> Logic One, Inc.
From: cbotta@taux01.nsc.com (Boaz Tabachnik)
Hello, John,
I've been using Specman for almost four years (since the erlier version).
Similar to this user, I didn't use the other tool (VERA in my case) and feel
'Specman expert' enough to make the comparison you proposed. However I
think that this comparison could not be done, since VERA is only a _subset_
of Specman.
Let's assume you're generating tests for a general purpose CPU. Let the
address of the next CPU instruction be a large (but simple to code)
function of the current CPU instruction and the machine's state (regs'
values etc.). Let's define the full range of 'legal' instructions, that
will not go to an 'illegal' address space (e.g. if you choose indirect jump
than only those pairs of registers are legal (according to their current
value). Let's not allow long instructions -- say we are near the end of a
block ...)
This is usually hard to program and drives automatic-test-generators to be
less 'aggressive' than they could be.
Using Specman you just need to supply the function that computes the next
instruction's address, then give a constraint like:
"keep next_address in range [ 0x0..0x7fff, 0x10000..0x10100 ];"
and Specman will do the rest. Beside the ability to code test environments
(high level, OO, string manipulation, regexps, debugger etc.) which both
VERA & Specman supply, Specman is able to GENERATE tests using its built-in
constraints solver. This is the core of the tool, and the reason we use it.
(Theoretically you could use Specman to just generate the tests, then run
the tests using VERA -- or any other tool -- but, there's probably no
reason to do it that way.)
- Boaz Tabachnik
National Semiconductor Tel-Aviv, Israel
[ Editor's Note: The July 27 "EE Times" (pg. 1) reports that Synopsys has
acquired System Science (w/ VERA) and the CEO of Verisity (which has
SpecMan) claims Synopsys tried to acquire Verisity but failed. - John ]
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