Abstract: This invention determines whether two circuit models have equivalent functionality. The method allows very fast comparison between two circuits taking advantage of previous work done. Whenever an apparatus associated with the method solves a problem, it stores information that learned during the solution of the problem, in a database. If the apparatus is presented with a new problem of determining equivalence between two portions of two circuits, it checks if it has seen sub-circuits similar to either of the two pieces before. If it has, it uses the knowledge cached during the previous checks to make the new check easier. Checking equivalence of two circuit models involves checking equivalence of many pairs of sub-parts. Even when the subsequent comparisons involve different circuits, it is possible to take advantage of the information acquired during previous equivalence checks.

Abstract: A highlighting system for use with electronic circuit design tools is provided for displaying signal waveforms and Register Transfer Logic (RTL) source code portions corresponding to a selected signal in the same window. The user selects a time and signal to be explored. Based on the selected time and signal, the values of all related signals are identified from a database generated by simulation of RTL source code. Nodes corresponding to the related signals are identified from a gate-level netlist corresponding to the RTL source code and the nodes responsible for the particular value of the selected signal at selected time are identified. The nodes are then mapped on to the RTL source code portions by a process of Instrumentation. The RTL source code portions so identified are then displayed. In particular, the portions of the RTL source code responsible for the particular value or transition in particular value of the signal at the selected time are highlighted.

Abstract: Methodology for verifying properties of a circuit model in context of given environmental constraints is disclosed. Verification of a specified property is performed by analyzing only a portion of the circuit model. The present methodology is also directed towards reducing the computation time for verifying the specified property. Further, the present methodology allows the connection of an additional circuit model to the circuit model in a non-intrusive manner. The connection is made without making any modifications to the description of the circuit model. This permits the straightforward specification of related environmental constraints and properties, which makes it possible to verify correct behavior of complex interfaces.