Introducing Performance Analysis
Introducing Performance Analysis
With the 5.3 release of ModelSim EE, a Performance Analyzer has been added as part of the simulation kernel engine. The Performance Analyzer provides a interactive graphical representation of where ModelSim is spending its time while running your design. This feature enables you to quickly determine what is impacting the design environment’s simulation performance. Those familiar with the design and validation environment will be able to find first level improvements in a matter of minutes.
For example, the Performance Analyzer might show that a non-accelerated
VITAL library cell is impacting simulation run time. Or, that a process is consuming more time than necessary because of non-required items on its sensitivity list. Or, that a testbench process is active even though it is not needed.
Or, that a random number process is consuming simulation resources when in a test bench is run in non-random mode. With this information, you can make changes to the VHDL or Verilog source code that will speed up the simulation.
A Statistical Sampling Profiler
The Performance Analyzer feature in VSIM is a statistical sampling profiler. It periodically "wakes up" and samples the current simulation at a user-determined rate, and records what is executing in the simulation during the sample period. The advantage of statistical analysis is that an entire simulation may not have to be run to get good information from the Performance Analyzer. A few thousand samples, for example, can be accumulated before pausing the simulation to see where simulation time is being spent.
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ModelSim SE Performance Analyzer ModelSim EE/SE User’s Manual