( SNUG 02 Item 18 ) -------------------------------------------- [ 5/15/02 ]
Subject: Nassda HSIM, Avanti StarSim, Synopsys EPIC NanoSim, Apache NSPICE
BETTER BUY AVANTI: Synopsys EPIC has tried keep up in the near-SPICE
simulation market with its new NanoSim tools, but Nassda's HSIM and Avanti's
StarSim still seems to be kicking Synopsys butt here. And it appears that
the new kid, Apache NSPICE, might be coming out to play, too.
Dataquest FY 2000 IC SPICE Market (in $ Millions)
Avanti ############################### $43.2 (62%)
Cadence ######### $11.8 (17%)
Nassda ####### $9.0 (13%)
others ##### $5.7 (8%)
"IC SPICE is a very volatile market. The lead shifts back and forth
fairly frequently. As a new technology comes out, people aren't
afraid to throw away their old SPICE tool for a new one."
- Gary Smith of Dataquest
"The SNUG'02 mixed signal tutorial on Synopsys NanoSim w/ VCD showed
some severe limitations to NanoSim that have already been addressed or
have functioning work arounds with the Avanti & Mentor solutions.
NanoSim's drive strength to resistance conversion at the A/D interface
for simulation does not work or translate for multi-voltage designs. A
lot of the new processes have a multi-voltage operation where the I/O
with data conditioning is at one voltage and the digital design logic
is at another. This is the most common interface for mixed analog and
digital boundries. The NanoSim tutorial and demo do not indicate that
NanoSim can address this. If/When the merger happens, this definately
puts StarSim in the driver's seat for high-capacity device level sim.
Also, John, these SPICE simulator guys are at it again. (Just like at
DAC last year.) In the last 4 weeks Nassda HSIM, Avanti StarSim and
Synopsys NanoSim all claim to have the largest installed base and the
highest accuracy. The speed/accuracy game they play is hilarious.
Nassda/Avanti/Synopsys benchmark metrics of 'high accuracy and slow' vs
'low accuracy and fast'. They then puposely put the numbers as 'high
accuracy vs low' and 'slow vs fast' and try to get EDA users to buy
off on it being real."
- Pallab Chatterjee of SiliconMap
"We use NanoSim/EPIC tools for mixed signal verification in our group.
I know that HSIM and Celestry are also being used elsewhere here."
- an anon engineer
"The combination of NanoSim and VCS for mixed-signal sims is very
interesting as I'm working on mixed signal designs. However our
company has already purchased NC-Verilog, and after speaking with
Synopsys people at the SNUG Synopsys night, I don't think NanoSim
will cleanly interface with NC-Verilog. It was stated that 'at
some point' that interface will be available. I'd hate to have to
switch the current simulation flow from a known commodity like
NC-Verilog just to use NanoSim."
- Eric Mitchell of Cypress Semiconductor
"Since we're a mixed-signal design house, my analog colleagues use
these kind of tools. They have tried several and have chosen
PowerMill. They are going to upgrade now to NanoSim. They are
very happy with this tool."
- an anon engineer
"We have both StarSim and TimeMill/PowerMill here. We just started to
evaluate Nanosim last week. We have evaluated Mach TA and Nassda HSIM
before. I think in the digital transistor level circuit simulation,
EPIC tool is the best in speed and result. Nanosim can be equally
good if Synopsys don't make mistake. Nanosim has also good promised
features in next release like mixed-language (SPICE, Verilog,
Verilog-A, Verilog-AMS) simulation making it more likely to support
whole chip simulation.
The only drawback of EPIC is the capacity due to flatten architecture.
Nanosim seems to have the same weak point compared with Nassda HSIM.
Nassda HSIM is good in accuracy but slower than EPIC tool although
capacity is a benefit. But we didn't bother to wait for it complete
our benchmark with maybe 1 months run time. But I think Nassda is
not aimed for pure digital world.
Mach TA performance varied widely among different cases. We have seen
good performance in many cases although some are really bad. I think
Mentor didn't take effort to promote this tool. It should be more
visible.
I personally believe StarSim(XT) will be vanished like Motive (vs.
PrimeTime) judging from past Synopsys behaviour no matter how good it
is. In the past few months, we didn't see any improvement on it from
Avanti just like Hspice."
- an anon engineer
"Nassda seems to give me the best runtimes."
- Tom Moxon of Moxon Design
"We evaluated TimeMill, PathMill, Nassda HSIM. I'm experienced with
PathMill, and understand what Celestry is doing. Not sure how to
compare static tools to dynamic tools, but here is my take:
1) For our applications, StarSimXT still outperforms Nassda HSIM and
(there's no doubt) it out performs Celestry's tools.
2) We also found that StarSimXT in certain modes (still more
accurate then TimeMill) is better performance from capacity
AND runtime than TimeMill.
3) As static timing tools go, PathMill is extremely complex for
some of the engineering staff who are used to dealing with gate
level timing. But, I believe after about 5-6 months of experience
with it, it is reasonably accurate and faster than dynamic
simulation of the same circuit. Typically, it doesn't do a lot
of the coupling stuff (glitches, timing windows) that gate level
tools have started to offer.
4) The new entrant 'Apache' with it's NSPICE might be a threat to
HSPICE, particularly due to Apache's improved convergence,
better/faster processing of the same matrices and also multi-port
network simulations. All this while also doing *transient*
s-parameter simulations for RF/high speed simulations!
On static side, I believe Sapphire/Sequence's Physical Studio products
(FormIT, FixIT, etc.) are still much faster and more accurate than
PrimeTime-SI."
- an anon engineer
"We looked at Nassda. We were very impressed with it's runtime,
however, it wasn't as accurate as Avanti's StarSimXT. For a lot of
circuits this inaccuracy would have been acceptible, but for our
simulations which is mostly on memory circuits we liked the accuracy
of StarSim. We didn't evaluate any other tools for circuit simulation.
The EPIC tool, Pathmill, is for static timing analysis. Comparison
between this tool and Nassda/StarSim isn't applicable."
- Mamun Rashid of Specular Networks
"Nassda HSIM and Avanti Star-SimXT are close. Nassda is ahead with
Star-SimXT close behind."
- an anon engineer
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