User guide

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OpenVera Native Testbench
Each time a user-specified activity occurs, a counter associated with
the bin is incremented. By establishing a bin for each state, state
transition, and variable change that you want to monitor, you can
check the bin counter after the simulation to see how many activities
occurred. It is, therefore, simple to check the degree of
completeness of the testbench and simulation.
VCS further expands this basic functionality to include two analysis
mechanisms: open-loop analysis and closed-loop analysis.
• Open-loop analysis monitors the bins during the simulation and
writes a report at the end summarizing the results.
• Closed-loop analysis monitors the bins during the simulation and
checks for areas of sparse coverage. This information is then
used to drive subsequent test generation to ensure satisfactory
coverage levels.
Coverage Models Using Coverage Groups
The coverage_group construct encapsulates the specification of a
coverage model or monitor. Each coverage_group specification has
the following components:
• A set of coverage points. Each coverage point is a variable or a
DUT signal to be sampled. A coverage point can also be an
expression composed of variables and signals. The variables may
be global, class members, or arguments passed to an instance
of the coverage_group.
• A sampling event (a general event not just an OpenVera sync
event) that is used for synchronizing the sampling of all coverage
points.