[SI-LIST] : Sweeping Temp within MonteCarlo in HSPICE

alaa alani (alaa@lsil.com)
Wed, 26 Nov 1997 12:02:58 GMT

Dear Coleagues,

(especially for those Hspice gurus!)

I have been using Monte Carlo analysis in Hspice to sweep a number of parameters such as package pin inductance, capacitance, etc. But when it comes to temperature, Hspice seems to be treating it differently. The problem I have now is how to sweep the temperature with the rest of parameters using Monte Carlo analysis.
I tried to define it as:

.param temp1 = aunif(50, 50) temp = 'INT(temp1)'

The syntax was acceptable but when I viewed the results, there was no effect of changing temperature. Instead there was another parameter "temper=25C" in the results which was constant and overiding the temperature value determined by MonteCarlo. Here's the .measure file:

MonteCarlo Hspice
| |
V V

index tempo@temp1 gb_max q0init q1init vdd_min temper alter#
1.0000 17.0000 0.6976 0.5046 1.5000 1.4756 25.0000 1.0000
2.0000 64.0000 0.6976 0.5046 1.5000 1.4756 25.0000 1.0000
3.0000 86.0000 0.6976 0.5046 1.5000 1.4756 25.0000 1.0000

The "tempo" was determined by MonteCarlo while "temper", which I have no control over it, was overriding it.

I also tried to define the temperature as a parameter in the .temp statement but it failed complaining: temp cannot be parameterised in .temp statement.

I could use .ALTER statement but this will lead to the generation of many .mt and .tr files which I am trying to avoid (i.e. The idea is to include all results in one file then use a spreadsheet to extract a set of equations that relate the result with each and every individual parameter).

Your help is much appreciated.

Regards,

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Dr. Alaa F. Alani
Senior Signal Integrity Eng. Tel: +44 (0)1344-413383
LSI-Logic Europe Ltd. Fax: +44 (0)1344-413186
Greenwood House, London Road
Bracknell, Berks RG12 2UB E-Mail: alaa@lsil.com
England
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