Patents by Inventor Carl P. Pixley

Carl P. Pixley has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 10325054
    Abstract: Methods and apparatuses are described for sharing inductive invariants while performing formal verification of a circuit design. Specifically, some embodiments assume at least an inductive invariant for a property to be true while proving another property. According to one definition, an inductive invariant of a property is an inductive assertion such that all states that satisfy the inductive assertion also satisfy the property. According to one definition, an inductive assertion describes a set of states that includes all legal initial states of the circuit design and that is closed under a transition relation that models the circuit design.
    Type: Grant
    Filed: January 29, 2014
    Date of Patent: June 18, 2019
    Assignee: Synopsys, Inc.
    Inventors: Himanshu Jain, Per M. Bjesse, Carl P. Pixley
  • Patent number: 9870442
    Abstract: Methods and apparatuses are described for proving equivalence between two or more circuit designs that include one or more division circuits and/or one or more square-root circuits. Some embodiments analyze the circuit designs to determine an input relationship between the inputs of two division (or square-root) circuits. Next, the embodiments determine an output relationship between the outputs of two division (or square-root) circuits based on the input relationship. The embodiments then prove equivalence between the circuit designs by using the input and output relationships.
    Type: Grant
    Filed: September 21, 2015
    Date of Patent: January 16, 2018
    Assignee: SYNOPSYS, INC.
    Inventors: Himanshu Jain, Carl P. Pixley
  • Publication number: 20160012177
    Abstract: Methods and apparatuses are described for proving equivalence between two or more circuit designs that include one or more division circuits and/or one or more square-root circuits. Some embodiments analyze the circuit designs to determine an input relationship between the inputs of two division (or square-root) circuits. Next, the embodiments determine an output relationship between the outputs of two division (or square-root) circuits based on the input relationship. The embodiments then prove equivalence between the circuit designs by using the input and output relationships.
    Type: Application
    Filed: September 21, 2015
    Publication date: January 14, 2016
    Applicant: SYNOPSYS, INC.
    Inventors: Himanshu Jain, Carl P. Pixley
  • Patent number: 9189581
    Abstract: Methods and apparatuses are described for proving equivalence between two or more circuit designs that include one or more division circuits and/or one or more square-root circuits. Some embodiments analyze the circuit designs to determine an input relationship between the inputs of two division (or square-root) circuits. Next, the embodiments determine an output relationship between the outputs of two division (or square-root) circuits based on the input relationship. The embodiments then prove equivalence between the circuit designs by using the input and output relationships.
    Type: Grant
    Filed: October 31, 2012
    Date of Patent: November 17, 2015
    Assignee: SYNOPSYS, INC.
    Inventors: Himanshu Jain, Carl P. Pixley
  • Publication number: 20150213167
    Abstract: Methods and apparatuses are described for sharing inductive invariants while performing formal verification of a circuit design. Specifically, some embodiments assume at least an inductive invariant for a property to be true while proving another property. According to one definition, an inductive invariant of a property is an inductive assertion such that all states that satisfy the inductive assertion also satisfy the property. According to one definition, an inductive assertion describes a set of states that includes all legal initial states of the circuit design and that is closed under a transition relation that models the circuit design.
    Type: Application
    Filed: January 29, 2014
    Publication date: July 30, 2015
    Applicant: Synopsys, Inc.
    Inventors: Himanshu Jain, Per M. Bjesse, Carl P. Pixley
  • Patent number: 8732637
    Abstract: Methods and apparatuses are described for formally verifying a bit-serial division circuit design or a bit-serial square-root circuit design. Some embodiments formally verify a bit-serial division circuit design using a set of properties that can be efficiently proven using a bit-level solver. In some embodiments, the set of properties that are used for verifying a bit-serial division circuit design does not include any terms that multiply a w-bit partial quotient with the divisor. Some embodiments formally verify a bit-serial square-root circuit design using a set of properties that can be efficiently proven using a bit-level solver. In some embodiments, the set of properties that are used for verifying a bit-serial square-root circuit design does not include any terms that compute a square of a w-bit partial square-root.
    Type: Grant
    Filed: July 30, 2012
    Date of Patent: May 20, 2014
    Assignee: Synopsys, Inc.
    Inventors: Himanshu Jain, Carl P. Pixley
  • Publication number: 20140033151
    Abstract: Methods and apparatuses are described for proving equivalence between two or more circuit designs that include one or more division circuits and/or one or more square-root circuits. Some embodiments analyze the circuit designs to determine an input relationship between the inputs of two division (or square-root) circuits. Next, the embodiments determine an output relationship between the outputs of two division (or square-root) circuits based on the input relationship. The embodiments then prove equivalence between the circuit designs by using the input and output relationships.
    Type: Application
    Filed: October 31, 2012
    Publication date: January 30, 2014
    Applicant: SYNOPSYS, INC.
    Inventors: Himansu Jain, Carl P. Pixley
  • Publication number: 20140033150
    Abstract: Methods and apparatuses are described for formally verifying a bit-serial division circuit design or a bit-serial square-root circuit design. Some embodiments formally verify a bit-serial division circuit design using a set of properties that can be efficiently proven using a bit-level solver. In some embodiments, the set of properties that are used for verifying a bit-serial division circuit design does not include any terms that multiply a w-bit partial quotient with the divisor. Some embodiments formally verify a bit-serial square-root circuit design using a set of properties that can be efficiently proven using a bit-level solver. In some embodiments, the set of properties that are used for verifying a bit-serial square-root circuit design does not include any terms that compute a square of a w-bit partial square-root.
    Type: Application
    Filed: July 30, 2012
    Publication date: January 30, 2014
    Applicant: SYNOPSYS, INC.
    Inventors: Himanshu Jain, Carl P. Pixley
  • Patent number: 6321186
    Abstract: A method for verifying an integrated circuit design using constraint information to develop a weighted data structure. In one embodiment, a binary decision diagram (BDD) includes a plurality of nodes (401, 402, 403, 404, 405, 406, 407, 420, and 430) representing signals and states in the circuit, and each node has a branching probability based on user-defined weights. The BDD represents the intersection of the input space and state space which satisfies the constraints. Current state information resulting from simulation is used to dynamically adjust the branching probabilities of the BDD on the fly. In one embodiment, the constraint information is applicable for formal verification of a portion of the circuit. In another embodiment, a simulation controller (12) receives design and constraint information and generates the program to control simulator (14).
    Type: Grant
    Filed: May 3, 1999
    Date of Patent: November 20, 2001
    Assignee: Motorola, Inc.
    Inventors: Jun Yuan, Carl P. Pixley, Stephen Kurt Shultz, Hillel Miller