Command Dictionary Analyze Observe
FastScan and FlexTest Reference Manual, V8.6_4 2-143
Analyze Observe
Tools Supported: FastScan
Scope: Atpg, Fault, and Good modes
Usage
ANAlyze OBserve
Description
Calculates observability coverage.
The Analyze Observe command identifies points that were inadequately observed
during application of the selected number of random patterns. FastScan calculates
observability test coverage, giving the percentage of adequately-observed pins.
You can specify the minimum number of observations (threshold) necessary for
adequate observation of a point with the Set Observe Threshold command. The
tool identifies the most difficult to observe fault points, those which fail the
threshold number, as inadequately observed.
After issuing the Analyze Observe command, you can display detailed results of
the analysis using the Report Observe Data command. This information helps you
identify circuit observe points that can increase observability for points that had
low observability. You can then evaluate the effect of these observe points by
using the Add Observe Points command and then reissuing the Analyze Observe
command.
You use this command primarily for simulating Built-In Self Test (BIST)
circuitry.
Examples
The following example calculates observability test coverage for pins which fail
to achieve a minimum number of observations during the simulated random
patterns:
set system mode fault
set random patterns 612
analyze observe
report observe data