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about spectre simulation warnings WARNING(CMI-2114)

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lhlbluesky

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about spectre simulation

when doing spectre simulation(IC5141, mmsim 7.1 version), there exist the following warnings and notice:
1\WARNING(CMI-2114):Define Q:Unit of quantity 'Q' is changed from 'coul' to 'C'
2\WARNING(CMI-2114):Define Freq:Unit of quantity 'F' is changed from 'N' to 'Hz'
3\Notice from spectre during IC analysis, during transient analysis 'tran'
Gmin=1pS is large enough to noticeably affect the DC solution
dV(I56.I2.I19.net30)=-849.572mV
Use the 'gmin_check' to eliminate or expand this report.
4\Notice from spectre during initial setup
Multithreading enabled:4 threads on system with 16 available processors.
Turbo mode Enabled.

what does the above warnings and notice mean? do they affect the final simulation results? how to understand and eliminate these warnings and notice?

pls give me some advice, thanks.
 

I wouldn't sweat the warnings, they look like something
that is happening in the include-chain for the model setup
and presumably this is on purpose and not a problem.

The Notice, you should check by altering the GMIN value
in the simulator options. It indicates that there's some
node that is changed by 850mV by overlaying the GMIN
mesh on the circuit; whether or not this matters, depends
on which one. It might be a high gain, high impedance
node and result in a negligible input or output error, or not.
Verify by looking at smaller GMIN conductances and seeing
if anything changes. Realizing that foundry models may be
not very
accurate for leakage or drain conductance anyway, and a
bit of conductance may be more realistic than none.

The last Notice means you've got a pretty good CAD budget
I guess.
 

i changed GMIN from 1e-12 to 1e-16, it was still the same as before, why? how to solve the problem, and how to deal with the warnings?
 

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