Abstract: A system for automatically transforming a given synchronous circuit description into an equivalent and provably correct desynchronized circuit description. Included in the automated transformation are techniques for synthesizing a variability-aware controller using a two-phase protocol, techniques for synthesizing a variability-aware controller using gated clocks and testability circuits, techniques for synthesizing a variability-aware controller optimized for performance, techniques for initializing the synthesized controller, techniques for dynamically minimizing power requirements, and techniques for interfacing the desynchronized circuit with external synchronous circuits. Also disclosed are techniques for implementing a system for automatically transforming a synchronous circuit description into an equivalent and provably correct desynchronized circuit description within the context of an electronic design automation design flow.

Abstract: In the field of functional verification of digital designs in systems that use an abstraction for portions of a circuit design to perform the verification proof, a tool is described for resolving inconsistencies between the design and abstractions for the design. The tool provides information to a user about intermediate steps in the verification process. In response, the user may provide insight about the design to allow the tool to adjust the verification analysis of the design. The information provided to the user, including possible conflicts between the design and its abstractions, may include visualization techniques to facilitate the user's understating of any inconsistencies.

Abstract: A system for automatically transforming a given synchronous circuit description into an equivalent and provably correct desynchronized circuit description. Included in the automated transformation are techniques for synthesizing a variability-aware controller using a two-phase protocol, techniques for synthesizing a variability-aware controller using gated clocks and testability circuits, techniques for synthesizing a variability-aware controller optimized for performance, techniques for initializing the synthesized controller, techniques for dynamically minimizing power requirements, and techniques for interfacing the desynchronized circuit with external synchronous circuits. Also disclosed are techniques for implementing a system for automatically transforming a synchronous circuit description into an equivalent and provably correct desynchronized circuit description within the context of an electronic design automation design flow.

Abstract: A counter abstraction tool generates an abstraction model for one or more counters in a circuit design for use with a formal verification system. The tool detects the presence of a counter in a circuit design, identifies one or more special values for the counter, and creates an abstraction for the counter. The tool can automatically perform the abstraction, guide a user in configuring the appropriate abstraction for the counter, or perform a combination of automatic and manual abstraction. The tool may further accommodate related counters.

Abstract: A system for automatically transforming a given synchronous circuit description into an equivalent and provably correct desynchronized circuit description. Included in the automated transformation are techniques for synthesizing a variability-aware controller using a two-phase protocol, techniques for synthesizing a variability-aware controller using gated clocks and testability circuits, techniques for synthesizing a variability-aware controller optimized for performance, techniques for initializing the synthesized controller, techniques for dynamically minimizing power requirements, and techniques for interfacing the desynchronized circuit with external synchronous circuits. Also disclosed are techniques for implementing a system for automatically transforming a synchronous circuit description into an equivalent and provably correct desynchronized circuit description within the context of an electronic design automation design flow.

Abstract: A system for automatically transforming a given synchronous circuit description into an equivalent and provably correct desynchronized circuit description. Included in the automated transformation are techniques for synthesizing a variability-aware controller using a two-phase protocol, techniques for synthesizing a variability-aware controller using gated clocks and testability circuits, techniques for synthesizing a variability-aware controller optimized for performance, techniques for initializing the synthesized controller, techniques for dynamically minimizing power requirements, and techniques for interfacing the desynchronized circuit with external synchronous circuits. Also disclosed are techniques for implementing a system for automatically transforming a synchronous circuit description into an equivalent and provably correct desynchronized circuit description within the context of an electronic design automation design flow.

Abstract: A system for automatically transforming a given synchronous circuit description into an equivalent and provably correct desynchronized circuit description. Included in the automated transformation are techniques for synthesizing a variability-aware controller using a two-phase protocol, techniques for synthesizing a variability-aware controller using gated clocks and testability circuits, techniques for synthesizing a variability-aware controller optimized for performance, techniques for initializing the synthesized controller, techniques for dynamically minimizing power requirements, and techniques for interfacing the desynchronized circuit with external synchronous circuits. Also disclosed are techniques for implementing a system for automatically transforming a synchronous circuit description into an equivalent and provably correct desynchronized circuit description within the context of an electronic design automation design flow.

Abstract: A system for automatically transforming a given synchronous circuit description into an equivalent and provably correct desynchronized circuit description. Included in the automated transformation are techniques for synthesizing a variability-aware controller using a two-phase protocol, techniques for synthesizing a variability-aware controller using gated clocks and testability circuits, techniques for synthesizing a variability-aware controller optimized for performance, techniques for initializing the synthesized controller, techniques for dynamically minimizing power requirements, and techniques for interfacing the desynchronized circuit with external synchronous circuits. Also disclosed are techniques for implementing a system for automatically transforming a synchronous circuit description into an equivalent and provably correct desynchronized circuit description within the context of an electronic design automation design flow.

Abstract: A system for automatically transforming a given synchronous circuit description into an equivalent and provably correct desynchronized circuit description. Included in the automated transformation are techniques for synthesizing a variability-aware controller using a two-phase protocol, techniques for synthesizing a variability-aware controller using gated clocks and testability circuits, techniques for synthesizing a variability-aware controller optimized for performance, techniques for initializing the synthesized controller, techniques for dynamically minimizing power requirements, and techniques for interfacing the desynchronized circuit with external synchronous circuits. Also disclosed are techniques for implementing a system for automatically transforming a synchronous circuit description into an equivalent and provably correct desynchronized circuit description within the context of an electronic design automation design flow.

Abstract: A system for automatically transforming a given synchronous circuit description into an equivalent and provably correct desynchronized circuit description. Included in the automated transformation are techniques for synthesizing a variability-aware controller using a two-phase protocol, techniques for synthesizing a variability-aware controller using gated clocks and testability circuits, techniques for synthesizing a variability-aware controller optimized for performance, techniques for initializing the synthesized controller, techniques for dynamically minimizing power requirements, and techniques for interfacing the desynchronized circuit with external synchronous circuits. Also disclosed are techniques for implementing a system for automatically transforming a synchronous circuit description into an equivalent and provably correct desynchronized circuit description within the context of an electronic design automation design flow.

Abstract: A system for automatically transforming a given synchronous circuit description into an equivalent and provably correct desynchronized circuit description. Included in the automated transformation are techniques for synthesizing a variability-aware controller using a two-phase protocol, techniques for synthesizing a variability-aware controller using gated clocks and testability circuits, techniques for synthesizing a variability-aware controller optimized for performance, techniques for initializing the synthesized controller, techniques for dynamically minimizing power requirements, and techniques for interfacing the desynchronized circuit with external synchronous circuits. Also disclosed are techniques for implementing a system for automatically transforming a synchronous circuit description into an equivalent and provably correct desynchronized circuit description within the context of an electronic design automation design flow.

Abstract: A counter abstraction tool generates an abstraction model for one or more counters in a circuit design for use with a formal verification system. The tool detects the presence of a counter in a circuit design, identifies one or more special values for the counter, and creates an abstraction for the counter. The tool can automatically perform the abstraction, guide a user in configuring the appropriate abstraction for the counter, or perform a combination of automatic and manual abstraction. The tool may further accommodate related counters.

Abstract: A method and apparatus for measuring the progress of a formal verification process using an analysis region, and measures the effectiveness of the current set of properties/requirements in verifying different portions of logic within the design. The present invention applies the concept of analysis region to analyze the properties/requirements for a design. The analysis region can be expanded or contracted either manually or automatically based upon the results of the analysis. The present invention generates a visual display that is available to the user that represents the amount of source code in the analysis region for a given property or multiple properties in comparison to the maximum possible analysis region. The present invention can display this information in a bar graph format, on a line-by-line basis for the source code and on a waveform display, for example.

Abstract: The present invention is directed to a system and a method for verifying properties of a circuit model while providing information to help the user manually modify a design analysis region and/or environmental constraints. While conventional systems attempt to substantially automate the entire formal verification process, the present invention iteratively provides information to the user about the cost and effect of changes to the environmental constraints and the analysis region. This information enables the user to weigh the effectiveness and efficiency of one or more modifications to the design analysis area and/or to the environmental constraints (assumptions). The information provided to the user can help a user compare a variety of alternative modifications in order to select the modifications that are efficient and effective.

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: The present invention is used for guiding formal verification of a circuit design in circuit simulation software to optimize the time required for verification of a circuit design. The invention modifies the analysis region being used for verification in order to optimize the time for verification. The invention allows for manual, semi-automatic, and automatic modification of the analysis region. The modification is done by either expanding or reducing the analysis region or by adding new rules as assumptions to the existing analysis region. The invention also uses the concept of an articulation point for modification of the analysis region. The modification of the analysis region is performed in a manner to optimize time and memory required for verification of the circuit design.

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.

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.