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Simulators >> Circuit Simulators >> spectre vs hspice
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Message started by thlcak on Mar 2^nd, 2007, 12:24pm

Title: spectre vs hspice
Post by thlcak on Mar 2^nd, 2007, 12:24pm

Hi all,

I've been using hspice all my career. I read posts here and most designers are using spectre.
Is spectre for analog, RF circuit design?

Thanks

Title: Re: spectre vs hspice
Post by Andrew Beckett on Mar 3^rd, 2007, 2:06am

Absolutely.

For a high level view, you can look at the datasheet, on http://www.cadence.com/products/custom_ic/spectre/index.aspx, but you might also want to look at Ken's book http://www.designers-guide.org/Books/dg-spice/index.html

Regards,

Andrew.

Title: Re: spectre vs hspice
Post by simon2 on Sep 20^th, 2007, 4:13pm

Hi thlcak,
like you I have used Hspice a long time - so long in fact I forgot how whilst using spectre for 12 years, then I had a chance to return to Hspice after becoming Spectre-centric via advice, celerity, eldo, pspice then more recently winspice.

For what it is worth, in terms of producing reliable, believable results most easily I would rate the tools thus: Hspice, Eldo, WinSPICE, Pspice, then trailing by a long way, Spectre. (Sorry Andrew, I know you are a great proponent of Spectre ...).

The reason I say this is that it seems that spectre is good at what it does, which is to provide an analogue interface into the Cadence tool suite and as such is intended (and may be the only) tool which can be used across multi-national, multi-site, multi-discipline teams. And it does that well.

What spectre does not well do is address what we analogue designers really need: to be able to directly and simply (and I stress simply as it often takes two days to work out how to do in spectre-cadence what can be done in hspice or WinSPICE in two or three minutes) and that is to access all of a device instance's parameters and to be able to manipulate them. I won't comment on how poor the scripting capabilities of spectre really are as I am likely to get sued!

Speaking from many hundreds of hours spent sorting out the issues for all of the above tools, I would say that on balance, stick with hspice, its results are far more accurate, despite supposedly using the same model files!

Remember Hspice is still the "gold standard" for the foundries, who at the end of the day underwrite the accuracy of the designs we do.

Perhaps my last comment could be that as a small company on a limited budget where these tools directly effect our "bottom-line" we have chosen to invested in Hspice, not Spectre.

- Hope my opinions haven't offended anyone; they are personal, but have been formed from years of practical (and pragmatic) experience of using the tools "in anger".

Cheers,
SimonH.

Title: Re: spectre vs hspice
Post by Andrew Beckett on May 16^th, 2009, 11:33pm

I'm not offended, but I suspect that you may be unaware of much of spectre's capabilities. It is possible to manipulate device parameters (very easy in SpectreMDL, for example), and you can access all operating point data very easily with wildcards these days.

You can either use SpectreMDL, OCEAN, or VerilogA for performing most of the "scripting" tasks you're likely to need. What you said wasn't very specific, but I'd be surprised if there are things you can do in hspice that you can't do just as easily (if not more easily) with spectre.

Whilst I'm clearly biased by virtue of working for Cadence, I have used multiple simulators as a designer over many years, and I would have no hesitation to using spectre if I was a designer again and no longer working for Cadence.

I'd be interested in hearing more specifics as to what you think spectre's failings are - if they really are failings, we can then fix them!

Regards,

Andrew.

Title: Re: spectre vs hspice
Post by Berti on May 19^th, 2009, 3:48am

Hi Andrew, SimonH,

Despite you having different opinions are you in agreement which simulator is faster? Spice or spectre? (for spice it probably depends on the actual tool)

Cheers

Title: Re: spectre vs hspice
Post by Geoffrey_Coram on May 19^th, 2009, 5:07am

Faster?? Ultrasim or nanosim are "faster" but Ken's put them in the "timing simulator" section of this forum because they're not as accurate.

If you really want a fast spice simulator, you might need to look at BDA (there are some postings on this forum), or Cadence's Spectre Turbo or APS. I'm not familiar with Synopsys' offerings in this space, nor its multithreading capabilities.