Jasper Design Automation, Inc.

Cadence Design Systems, Inc.

Lawrence Loh

Chung-Wah Norris Ip

Howard Wong-Toi

Vigyan Singhal

Kathryn Drews Kranen

Victor Markus Purri

Antonio Celso Caldeira, Jr

Claudionor Jose Nunes Coelho

Caio Araújo Teixeira Campos

Magnus Björk

Fabiano Cruz Peixoto

Rajeev Kumar Ranjan

Craig Franklin Deaton

Jamil Raja Mazzawi

Yann Alain Antonioli

Andrea Iabrudi Tavares

Beth C Isaksen

Soe Myint

Marcus Vinicius Da Mata Gomes

Xiaoyang Sun

Barbara Jobstmann

Ziyad Hanna

Lars Lundgren

Harry David Foster

Breno Rodrigues Guimaraes

Artur Melo Mota Costa

Sergey Khaikin

Disclosed are techniques for verifying an electronic design using hierarchical clock domain crossing verification techniques. These techniques identify an electronic design including a top hierarchy and one or more instances at a first child hierarchy below the top hierarchy. The electronic design may be decomposed into a top hierarchy block for the top hierarchy and one or more child blocks for the one or more instances. A plurality of data structures may be generated by separately processing the top hierarchy block and the one or more child blocks on one or more computing nodes. One or more clock domain crossing structures may be identified in the electronic design at least by integrating the plurality of data structures.

Methods, systems, and articles of manufacture for verifying an electronic design using hierarchical clock domain crossing verification techniques

A formal verification approach verifies data access and data propagation paths in a circuit design by proving the unreachability of path cover properties of the circuit design. A security path verification system receives an original circuit model of a circuit design, along with parameters identifying a first location within the circuit design that is a source of tainted data and a second location within the circuit design that is coupled to the first location. The security path verification system also receives a selection of portions of the circuit design to be excluded from the verification analysis. Using an abstracted version of the exclude portions, the security verification system generates a second circuit model of the circuit design for use in determining whether the tainted data can reach the second location from the first location within the circuit design.

Security data path verification

Various mechanisms and approaches identify multiple cells in an electronic design and multiple sets of stall prevention requirements or multiple sets of transactions for the multiple cells and determine dependencies between stall prevention requirements. A graph is constructed to represent the dependencies and the stall prevention requirements or the transactions involved in the dependencies by using the stall prevention requirements or the transactions as the nodes and the dependencies as the arcs connecting the nodes in the graph. One or more loop analyses are performed on the graph to identify one or more loops as one or more potential deadlocks. False deadlocks may be eliminated from further processing. The analyses and deadlock detection may be independently performed for each cell in sequence or in parallel to divide and conquer a complex electronic system design.

Method, system, and computer program product for verifying an electronic design using stall prevention requirements of electronic circuit design models of the electronic design

Various mechanisms and approaches identify a first electronic design component at least by traversing at least a portion of the electronic design and generate a representation of the electronic design by interconnecting one or more duplicated electronic design components within the representation. The first electronic design component may include a destination electronic design component with a backward traversal of the electronic design. One or more fan-in electronic design components may be duplicated into the one or more duplicated electronic design components. One or more CDC effect models are automatically injected into the representation by adding the one or more CDC effect models along one or more paths in the representation. Proof results are generated at least via proving or disproving one or more checkers for the electronic design by verifying or simulating the representation with the one or more CDC effect models that are automatically injected into the representation.

Methods, systems, and computer program product for verifying electronic designs with clock domain crossing paths

An improved approach is provided to implement equivalency checking. A check is performed as to whether two designs are equivalent without needing to analyze their outputs on a cycle-by-cycle basis. Instead, the two designs are checked to see if they are equivalent on the transaction-level. This approach abstracts the timing delays between the two designs, which allows verification of data transportation and transformation between the designs.

Method and system to perform equivalency checks

A register transfer level (RTL) design is received which models a digital circuit in terms of the flow of digital signals. A power intent description is received which may include a description of power domains, identification of retention flops for each power domain, a list of isolation signals, and power switch definitions. A transformed RTL is produced accounting for functionality described in the power intent description. The transformed RTL includes flops designated as retention flops and non-retention flops. A retention flop module analyzes the flops to ensure that flops are properly designated as retention or non-retention flops. A verification module performs power aware sequential equivalence checking on various RTL and power intent descriptions to verify that RTL and power intent description outputs behave the same when accounting for power states.

Power aware retention flop list analysis and modification

Veryifing low power functionality through RTL transformation

The result of a property based formal verification analysis of a circuit design may include at least one counterexample for each property that is violated, which a user can use to debug the circuit design. To assist the user in this debugging process, a debugging tool applies one or more soft constraints to a counterexample trace that simplify the appearance of the trace when displayed as a waveform. The debugging tool thus facilitates a user's understanding of what parts of the counterexample trace are responsible for the property failure. Also described is a power analysis tool that increases the noise level of a trace for a circuit design in order to facilitate analysis of the circuit design's power characteristics.

Constraining traces in formal verification

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.

Indexing behaviors and recipes of a circuit design

A verification system determines proof of the absence of a deadlock condition or other data-transport property in a multi-system SoC using helper assertions derived from a transaction definition. The verification system receives the circuit design information along with a transaction definition for one or more ports of the SoC. Once specified, the transaction definition is instantiated into the full system or subsystem RTL, generating an expanded RTL and a deadlock property. Data flow through the RTL is analyzed to extract helper assertions describing how the data flowed through the RTL. Helper assertions are automatically extracted to aid in the verification of the absence of a deadlock condition. Using the helper assertions, the formal engine applies one or more techniques to formally analyze the circuit design to prove the absence of a deadlock condition.

Formal verification of deadlock property

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.

Managing formal verification complexity of designs with multiple related counters

A system and method for identifying, for a selected signal, those signals whose value is relevantly determined based upon a value of the selected signal, where a set of signals to be examined is identified as those signals that satisfy one or more of the following criteria: (1) they are RTL load signals of the selected signal, (2) they are RTL load signals that are also in an analysis region, (3) they are RTL load signals within the analysis region that also contribute to a proof target, and/or 4) they are RTL load signals that contribute to the proof target. In one embodiment of the present invention the selected signal at a selected time step relevantly determines a target signal at an associated time step if one of the following items is true: (1) if the value of the selected signal at the selected time step changes (from 0 to 1 or from 1 to 0), the value of the target signal must change, or (2) if the value of the selected signal does not change, the value of the target signal at its associated time step cannot change regardless of how the rest of the inputs to the logic driving the target signal changes. Another embodiment of the present invention, the selected signal at the selected time step relevantly determines a target signal at an associated time step if the value of the selected signal at the selected time step were different then the value of the target signal at the associated time step would be different.

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Milpitas, CA, United States of America

Lawrence Loh