( ESNUG 375 Item 7 ) -------------------------------------------- [06/28/01]
Subject: ( ESNUG 374 #4 ) What's The User Dirt On Electromigration Tools?
> Cadence has such a signal wire EM tool, and has had one for quite some
> time. The Cadence tool SE-SI (Silicon Ensemble - Signal Integrity) has
> handled the signal line electromigration problem for several years. We
> call this effect 'wire self heat', but it's the same effect. It's also
> sometime called 'Joule heating'. ...
>
> - Lou Scheffer
> Cadence
From: Caesar Abedin <cabedin@amcc.com>
John,
OK, now that I've heard from every EDA vendor out there, some trying to sell
us their place and route tool and others trying to sell their extraction
tool. It seems that there are 3 major vendors out there that have a
stand-alone tool for EM analysis on signal nets - ElectronStorm (Simplex),
Railmill (Synopsys), and Mars (Avanti). I was wondering if the masses of
users out there have any recommendations/warnings on them.
- Caesar M. Abedin
Applied Micro Circuits Corp. Andover, MA
---- ---- ---- ---- ---- ---- ----
From: Michael Zaslavsky <michael.zaslavsky@intel.com>
Hi John,
Avanti also has signal net analysis, however not in Star-RC-XT. I hope
they will have it in Star-RC-XT, but for the time being I have to use
Star-RC/Star-Power for that.
Before explaining the flow, let me say that power/ground EM verification
is also done here by combining Star-RC/Star-Power and Star-RC-XT. This
combination allows me to do hierarchical analysis at block and chip level.
Most of my APR blocks have embedded custom blocks, which I do not extract
into to avoid capacity problem w/ transistor-level extraction/verification.
Instead, I am using macromodels generated by Star-Power during transistor-
level analysis. In the coming weeks I'll set up Star-RC-XT at transistor
level as well.
Regarding signal nets verification, -- there is also EM part of it, not only
Self-Heating. The fact is that even in APR designs I have C > Cmax, so I
cannot guarantee that my std cells are EM proven. As for custom made blocks
the whole interconnect metallization should be verified wrt to EM.
Self-Heating analysis is a combination of local interconnect heating
analysis and heat dissipation. The first is pretty much about RMS current
density, which is calculated by Star-Power only in dynamic mode. So, I
have the flow that runs static analysis first to get approximate values for
Irms, and then filter out the false violations with some heat-dissipation
analysis. The dynamic mode is still useful, when you are left with a
limited number of nets. Star-Sim is much faster than HSpice, but not as
fast as static analysis.
- Michael Zaslavsky
Intel
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