eldo_user

Monte Carlo Analysis
Output of Uncertainty Analysis (the .chi File)
• Standard Deviation based on nominal run is also computed:
• The histogram. You can specify the number of bins for the histogram in the .MC
command using the NBBINS parameter (the default is 10). The histogram is output in
the binary output file and displayed with EZwave.
• Approximation of the Yield. It is defined as the percentage of circuits that satisfy a userdefined
set of performance specifications. The LBOUND and UBOUND arguments of
the .EXTRACT command are used to control the lower and upper specifications
imposed on the extracted value. In our example this specification is given by a single
lower bound on the frequency: LBOUND=280Meg.
*** MC runs which passed all extract: 191 ( 96.46465 %)
MC run 46 Failed
MC run 53 Failed
MC run 77 Failed
MC run 94 Failed
MC run 144 Failed
MC run 147 Failed
MC run 148 Failed
A Monte Carlo analysis can use this information to divide the acceptability region in the
parameter space into two parts: the “pass” circuits with acceptable performance and the
“fail” circuits with unacceptable performance.
Bootstrap Estimates for Mean and Standard Deviation
The bootstrap is a general method for doing statistical analysis without making strong
parametric assumptions. It was originally designed to estimate bias and standard errors for
statistical estimates. In Eldo, the bootstrap technique is used to estimate the uncertainty of a
statistic such as the mean and the standard deviation.
These computations are given after the histogram. In our example, the following bootstrap
confidence intervals for AVG are obtained:
[------ Average value ------------]
Level LeftLimit Estimate RightLimit
95.0000% 3.1487E+08 3.1766E+08 3.1994E+08
99.0000% 3.1438E+08 3.1766E+08 3.2103E+08
99.9000% 3.1401E+08 3.1766E+08 3.2142E+08
99.9900% 3.1465E+08 3.1766E+08 3.2123E+08
99.9990% 3.1290E+08 3.1766E+08 3.2162E+08
470
Eldo® User's Manual, 15.3