Functional test-bench refinement through automatic constraint extraction

Functional verification continues to be one of the most expensive and time-consuming steps in a typical design process. Effective tests can achieve higher verification coverage in shorter time, which saves engineering resource and improve confidence on the quality of the design. However, generating effective tests for complex designs has always been a challenging problem. Instead of generating tests, the idea is to analyze the simulation trace of tests from an initial test-bench, learn from it, and extract the input constraints for controlling signals internal to the unit under test. For the experiments we used OpenSPARC T1 which is a 64-bit open-source microprocessor designed by SUN Microsystems. OpenSparc is a complex design that makes it very suitable for the experiments.