eldo_user

Monte Carlo Analysis
Input/Output Samples
The column labelled “Value(indep)” represents the independent variations associated to a
random variables. In the previous example it is the random variable V i th, loc . The effective value
V i th is given in the column “Value(effect)”. When the variable is not associated to local
variations, the values in the columns are the same (there is no correlation).
If the netlist contains swept parameters or .ALTER blocks, Eldo generates multiple .mci files. In
this case, the table for each random variable contains an additional column, Index in Loop,
which identifies the Monte Carlo analysis that the .mci file corresponds to. Refer to “Monte
Carlo Analysis With a Varying Circuit” on page 419 for more information.
Output Sample
The list of output measures is printed in the first part of the file. Users will also find a short
summary of the Monte Carlo simulations. We give the nominal value, the average value and the
empirical estimation of the Yield. This estimation is given in the column “Pass (percent)”. The
column “Number of Undef” counts the number of runs with Undefined value.
. ==> List of Output Measures:
.
.
. Index Number Nominal Lower Mean Upper Pass Name
.of Meas of Undef Value Bound Value Bound (percent) of Meas
. -------------------------------------------------------------------------------
. 1 0 8.380e-01 7.650e-01 8.372e-01 8.850e-01 84.70 % MAX
. 2 0 2.196e+00 -Infinity 2.195e+00 2.200e+00 60.30 % BW
. 3 0 -5.443e-02 -5.400e-01 -5.443e-02 Infinity 100.00 % IVDD
.
The second part is a sequence of tables containing the detail results of the Monte Carlo runs.
Each table has n rows where n is the number of MC runs. The first column gives the run index
which corresponds to the column “Value”, and the order of the run that corresponds to the order
statistics. In other words, the column “Value” gives the sequence Y 1 , Y 2 , ..., Y n , and the column
“Value (order)” gives the sequence Y [1] , Y [2] , ..., Y [n] of order statistics.
.
. ==> Main sample (runs 1..1000)
.
.
.
. Index Output Measure 1 : MAX
. of Run/ Index
. Order of Meas Value P/F Value(order) CDF(Cum.Prob) +/- T*STD
. ------------------------------------------------------------------------------
1 1 8.7112e-01 1 7.1261e-01 1.0000e-03 6.1992e-05
2 1 8.9774e-01 0 7.1281e-01 2.0000e-03 1.2385e-04
3 1 7.8203e-01 1 7.2847e-01 3.0000e-03 1.8560e-04
4 1 8.1764e-01 1 7.3749e-01 4.0000e-03 2.4722e-04
5 1 8.6639e-01 1 7.3848e-01 5.0000e-03 3.0872e-04
6 1 7.8002e-01 1 7.3881e-01 6.0000e-03 3.7009e-04
...
Eldo® User's Manual, 15.3 507