An executable circuit design is used to generate waveforms, from which behaviors of the circuit are captured. The behaviors and various combinations thereof can then be saved in a database, along with descriptions and other metadata about them, thereby generating a behavioral index of the circuit design code. Behavioral indexing of circuit designs allows a user to maintain an indexed behavior database, track changes in behaviors as the circuit design's executable description evolves, and figure out how the executable description can be reused in different projects. When applied to digital design development, it facilities the current design and verification effort, as well as design reuse down the line.