1 Reply Latest reply on Sep 21, 2012 4:25 PM by anju_prakash

    Monte Carlo Analysis Help needed..


      I am facing trouble with running montecarlo analysis in Pyxis schematic entry, i am trying to do a simple experiment of a CMOS inverter dc sweep analysis. I need to perform monte carlo simulations for this test bench. But while simulating the design with monte carlo option enabled, it is giving a warning message that it has ignored .MC because no rules for LOT or DEV variations are specified. I am unable to add monte carlo specific library to the design.

      Please help me in doing monte carlo analysis by atleast providing a tutorial document.. Thanks in advance...

        • 1. Re: Monte Carlo Analysis Help needed..

          Setting up a Monte Carlo Analysis

          Use this procedure to set up a Monte Carlo analysis.

          The Monte Carlo (MC) analysis gathers statistical data derived from estimates of the random

          variability of all circuit components. MC analysis is used in conjunction with AC, DC and

          transient analyses.

          Task Prerequisites

          • Schematic is open in simulation mode.


          1. Select the instances or nets on the schematic to use for standard deviation reference.

          2. Click the Setup Simulation icon on the Edit Toolbar, and then select the Monte

          Carlo panel. The Setup Simulation Dialog Box (Monte Carlo Panel) displays.

          3. Toggle the Monte Carlo Analysis to enable/disable it by clicking the Enable MC

          Analysis checkbox. When enabled, the setup options for the Monte Carlo runs become


          4. Define the random variables, simulation control options, and global setup for the

          selected objects.

          5. Click Apply. A .MC command is written to the simulation command file.


          The Monte Carlo Distribution settings are ignored for Instances.


          Options for the MC distribution settings include:

          • Enabled — If this option is not checked, it indicates that a Monte

          Carlo analysis need not be performed.

          • LOT Distribution and DEV Distribution — Specify the type of

          LOT and DEV Distributions by selecting from the dropdown list.

          By default, this option is disabled for both the fields. If you select

          Gaussian or Uniform as the Distribution type, you can enter the lot

          variance value respectively.


          • When you select Gaussian distribution, the label for the lot

          variance changes to Sigma enabling you to enter the standard

          deviation value.

          • When you select Uniform from the dropdown list, the label

          changes to Upper/Lower Bound enabling you to enter the value

          for the range above/ below the mean value where sampling takes


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