Re: get nominal results from MC analysis

On Thu, 20 Sep 2007 17:52:54 -0000, JD <Jiandong.Ge@xxxxxxxxx> wrote:

Thanks very much for the answer.

However, if I use

export output=oceanEval(....)

inside montecarlo loop, it seems in the mc.mcdata, there is no nominal
output available.

Is there a way to get the nominal output saved in mc.mcdata or some
other file in the .raw directory?

Thanks

JD


If you're running monte carlo either from ADE, or directly from a spectre
netlist, the nominal value of each expression is never written into the mcdata
(or any other ASCII file). You will however get all the PSF results of the
noninal run, and so you can always use OCEAN to evaluate the same
expressions again on the nominal data set. One of the main purposes
of the nominal run is to check the expressions are OK and to abort if they're
not - rather than running 50 sims and getting bad results for every point.

However, if you're running standalone (perhaps you are, since you refer to the
..raw directory), you could use spectremdl to run the monte-carlo simulations.
This is a rather nice flow for standalone use - there's examples in the
SpectreMDL workshop (in <MMSIMinstDir>/tools/spectre/examples )
of doing this. In the monte.mdl example, you can see what happens if you
set donominal='yes - you get the result of the "0" iteration in
the results files. In the MDL flow, it also outputs the mean and stddev and
so on rather than you having to compute it yourself. The other difference is
that your expressions are written in MDL rather than OCEAN - but that's not
a massive problem.

Regards,

Andrew.
--
Andrew Beckett
Senior Solution Architect
Cadence Design Systems, UK.
.