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pancho_hideboo

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Re: bdasim vs spectre
Reply #15 - Feb 05^th, 2010, 8:07am

Andrew Beckett wrote on Feb 5^th, 2010, 2:15am:

Pancho Hideboo's reference was to another post which was discussing the behaviour in hspice.

It is wrong. See the left graph plot of the following.
http://www.designers-guide.org/Forum/YaBB.pl?num=1260585749/5#5

Here I compared time step behavior of HSPICE and Cadence Spectre
when "$bound_step" are used in addition to "@(timer)".

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michael chapman

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Re: bdasim vs spectre
Reply #16 - Feb 5^th, 2010, 8:47am

Hi Mayank,

You wrote :-

Quote:

author=Mayank_Singh link=1264764783/0#12 try converging simultaneously wheile it's running tstab).

I don't understand this either. PSS does not converge (shooting method) until the tstab initial stabilization transient run is complete.

Quote:

2 doubts :--- 1> When BDA generates the psfbin output, it generates period jitter, period jitter_flicker, and period jitter_white under the pnoise-SummaryStatistics.Pnoise section. May i know what formula does bdasim use to compute these values ???

Please contact me directly and we can discuss.

I suggest that you use nutbin output format when running PSS/PNoise. If you do this then you will get separate plots of phase noise (white) and phase noise (white + flicker). These outputs are not available in psfbin format. Use BDA's Wavecrave waveform tool to view BDA's nutbin format.

Quote:

2> Do the PPV values under the section pnoise-NoiseSourceIntensityNoiseSensitivityandProduct.pnoise indicate ISFs [ impulse sensitivity functions ] at these nodes ??

Yes, they do.

Regards
Michael

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Andrew Beckett Senior Fellow Offline Life, don't talk to me about Life... Posts: 1392 Bracknell, UK	Re: bdasim vs spectre Reply #17 - Feb 6^th, 2010, 6:44am Pancho Hideboo, I understand the confusion now. I was talking about using bound_step instead of @timer, whereas you were talking about using it as well as @timer. If using it instead of, the simulator has more freedom. Regards, Andrew.
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Andrew Beckett Senior Fellow Offline Life, don't talk to me about Life... Posts: 1392 Bracknell, UK	Re: bdasim vs spectre Reply #18 - Feb 6^th, 2010, 6:51am Andrew Beckett wrote on Feb 5^th, 2010, 2:15am: You may also want to try APS. From MMSIM72, you can just use "spectre -aps" to run in APS mode Had a bit of a brain blip earlier. That should have been spectre +aps not -aps. Regards, Andrew.
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