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Simulators >> Circuit Simulators >> Spectre vs SpectreS and SpectreRF
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Message started by Analog Designer on Jan 18^th, 2005, 10:00pm

Title: Spectre vs SpectreS and SpectreRF
Post by Analog Designer on Jan 18^th, 2005, 10:00pm

Hi all,
Does anybody know what is exactly the difference between Spectre and SpectreS. Which one is older? and where is SpectrRF is it a part of Spectre?
because in our Cadence setup I can just see Spectre and SpectreS and no SpectreRF is it a problem of setup?
Thanks

Title: Re: Spectre vs SpectreS and SpectreRF
Post by Ken Kundert on Jan 19^th, 2005, 6:53am

Use Spectre. SpectreS is obsolete. SpectreRF is part of Spectre.

-Ken

Title: Re: Spectre vs SpectreS and SpectreRF
Post by Analog Designer on Jan 19^th, 2005, 8:33am

Hi,

So still the question is that why SpectreS exists? and if Spectre is better why SpectreS has more options. Is it a problem of my setup i.e. our installation is out-of0date or this is the way it works?

Also I checked Cadence example on siumulating low-noise amplifiers and it has used SpetreS rather than Spectre eventhough it always say that using SpectreRF for simulation.

I cannot find any document on SpectreS in Cadence but in some exapmples it has been used instead of Spectre

Title: Re: Spectre vs SpectreS and SpectreRF
Post by mohammad on Jan 19^th, 2005, 9:15am

Hi,
I made a mistake in my previous post. SpectreS doesn't have more options than Spectre but still when I look into Cadence documentation I find a part: SpectreRF Help for SpectreS, Product Version 5.0.0
What does this mean?

M.H.

Title: Re: Spectre vs SpectreS and SpectreRF
Post by Andrew Beckett on Jan 19^th, 2005, 12:50pm

Elaborating on Ken's answer a bit (I'm sure this has come up before)...

There is one simulator, called spectre. spectreRF is an option to spectre which allows access to additional analyses (pss, pac, pxf, pnoise, psp, qpss, qpac, qpxf, qpnoise, qpsp, envlp) .

In the Analog Design Environment, there are two interfaces to the simulator. spectreS and spectre. In both cases you can access spectre and spectreRF features, but spectreS is limited because it is obsolete.

spectreS is the older interface which operates via the "cdsSpice Socket" - the "S in spectreS stands for "Socket". This was needed in the past as the standard way of integrating simulators in ADE because commonly simulators did not have a strong parameterisation and expression handling capability. cdsSpice however had a fairly powerful preprocessing language which could act as the preprocessor for other simulators.

However, spectre has had a good expression language for some time now, and so it made sense to cut out the middle man and interface directly to the simulator. So the spectre interface was created which directly talks to spectre, and is much faster as a result. Since spectre interface was introduced in IC443, spectreS has not been enhanced - so many of the newer spectre and spectreRF analyses are not there in spectreS.

The only reason you would use spectreS is if you're using an old design flow which only supports spectreS (the CDF information in primitive libraries needs to support the interface). Otherwise you should steer well clear of it and use the spectre (direct) interface. We keep the old interface because customers who cannot move, or who have very slow CAD departments (joke ;) ) would complain like mad if we removed it!

Regards,

Andrew.