Abstract: A security verification system performs security verification of a circuit design. The security verification system simplifies formal security verification of the circuit design by replacing circuit blocks of the circuit with black box circuit blocks. The security verification system instruments the circuit design so that black-boxing can be performed for security verification without changing the security decision over the data paths. The security verification system uses dependence information of the inputs and outputs of the black box to connect inputs of the circuit block with outputs of the circuit block. The black-box circuit block keeps the logic inside the cone of influence of clocks and resets. The system performs security verification of the circuit design by proving a non-interference property of the instrumented circuit design.

Abstract: A system and method for providing formal property verification across circuit design versions is described. In one embodiment, the system receives a first version and a second version of a circuit design. The received first version has a first set of constraints, a first set of next-state functions representing the first version of the circuit design, and a first property that has been verified as true for the first version of the circuit design. The received second version has a second set of constraints, a second set of next-state functions representing the second version of the circuit design, and a second property for the second version of the circuit design. The described embodiments further construct a composite circuit design based on the first set of constraints, the first set of next-state functions, and the first property and further based on the second set of constraints, the second set of next-state functions, and the second property.

Abstract: Techniques and systems for classifying non-detected faults (NDFs) in a formal verification test-bench are described. A sequential equivalence checking formulation can be constructed based on an integrated circuit (IC) design and a set of NDFs, wherein the set of NDFs do not falsify a first set of properties of the IC design, wherein said constructing the sequential equivalence checking formulation comprises creating a second set of properties based on the set of NDFs, wherein each property in the second set of properties corresponds to an NDF in the set of NDFs. A formal sequential equivalence checking tool can be used to prove the second set of properties in the sequential equivalence checking formulation. Next, for each property in the second set of properties that is disproven by the formal sequential equivalence checking tool, some embodiments can classify a corresponding NDF in the set of NDFs as an observable NDF.

Abstract: A security verification system performs security verification of a circuit design. The security verification system simplifies formal security verification of the circuit design by replacing circuit blocks of the circuit with black box circuit blocks. The security verification system instruments the circuit design so that black-boxing can be performed for security verification without changing the security decision over the data paths. The security verification system uses dependence information of the inputs and outputs of the black box to connect inputs of the circuit block with outputs of the circuit block. The black-box circuit block keeps the logic inside the cone of influence of clocks and resets. The system performs security verification of the circuit design by proving a non-interference property of the instrumented circuit design.

Abstract: Disclosed is a technology for parallelized design verification of two circuit designs at a register transfer level. A plurality of potential equivalent sub-circuit pairs is identified from the circuit designs to create a proof-tree structure. The proof-tree structure includes a root-proof, a plurality of parent-proofs downchain of said root-proof and a plurality of child-proofs downchain of at least one of the parent-proofs. Each one of the child-proofs is associated with a first equivalency status of one of the potential equivalent sub-circuit pairs. The parent-proofs are associated with second equivalency statuses dependent upon the first equivalency statuses of downchain child-proofs. The root-proof is associated with a third functional equivalency status of the two circuit designs dependent upon the second equivalency statuses of downchain parent-proofs. This Abstract is not intended to limit the scope of the claims.

Abstract: A device may store a credit value for each of multiple output components. The device may receive packets from a network device via an input component. The device may cause the input component to queue the packets. The device may selectively dequeue a packet from the input component, to be sent to an output component, based on whether the credit value for the output component satisfies a credit threshold. The device may send the packet to the output component based on a destination of the packet when the packet is dequeued from the input component. The device may determine a size of the packet after the packet is dequeued. The device may update the credit value for the output component based on the size of the packet. The device may output the packet to another network device via the output component.

Abstract: A device may store a credit value for each of multiple output components. The device may receive packets from a network device via an input component. The device may cause the input component to queue the packets. The device may selectively dequeue a packet from the input component, to be sent to an output component, based on whether the credit value for the output component satisfies a credit threshold. The device may send the packet to the output component based on a destination of the packet when the packet is dequeued from the input component. The device may determine a size of the packet after the packet is dequeued. The device may update the credit value for the output component based on the size of the packet. The device may output the packet to another network device via the output component.

Abstract: A device may store a credit value for each of multiple output components. The device may receive packets from a network device via an input component. The device may cause the input component to queue the packets. The device may selectively dequeue a packet from the input component, to be sent to an output component, based on whether the credit value for the output component satisfies a credit threshold. The device may send the packet to the output component based on a destination of the packet when the packet is dequeued from the input component. The device may determine a size of the packet after the packet is dequeued. The device may update the credit value for the output component based on the size of the packet. The device may output the packet to another network device via the output component.

Abstract: A design is verified by using equivalence checking to compare a word-level description of the design to a bit-level description of the design. A word-level data flow graph (DFG) based on the word-level description and a bit-level DFG is obtained. Structural analysis is used to reduce the graphs and partition them into smaller portions for the equivalence checking. The analysis includes searching the bit-level DFG to find partial-product encoding and removing redundancy from the bit-level DFG. A reference model with architectural information from the bit-level DFG is created based on the word-level DFG. The reference model is reduced and equivalence checked against the bit-level DFG to determine if the word-level description is equivalent to the bit-level description.

Abstract: A design is verified by using equivalence checking to compare a word-level description of the design to a bit-level description of the design. A word-level data flow graph (DFG) based on the word-level description and a bit-level DFG is obtained. Structural analysis is used to reduce the graphs and partition them into smaller portions for the equivalence checking. The analysis includes searching the bit-level DFG to find partial-product encoding and removing redundancy from the bit-level DFG. A reference model with architectural information from the bit-level DFG is created based on the word-level DFG. The reference model is reduced and equivalence checked against the bit-level DFG to determine if the word-level description is equivalent to the bit-level description.

Abstract: Methods and systems for generating verification conditions and verifying the correctness of a concurrent system of program threads are described. The methods and systems determine and employ mutually atomic transactions to reduce verification problem sizes and state space for concurrent systems. The embodiments provide both an adequate and an optimal set of token-passing constraints for a bounded unrolling of threads.

Abstract: Methods and systems for generating verification conditions and verifying the correctness of a concurrent system of program threads are described. The methods and systems determine and employ mutually atomic transactions to reduce verification problem sizes and state space for concurrent systems. The embodiments provide both an adequate and an optimal set of token-passing constraints for a bounded unrolling of threads.

Abstract: A system and method for program testing includes, using a static analysis, determining dependency relations of enabled running processes in a program. The dependency relations are organized in a matrix to provide an interface for exploring the program. A reduced set of possible executions obtained by removal of redundant interleavings as determined with respect to the dependency relation, is explored on the program in a stateless exploration process that analyzes executed states and transitions to verify operation of the program.