Patents by Inventor Albert E. Casavant

Albert E. Casavant 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: 7111259
    Abstract: A method and system of crosstalk mitigation in integrated circuits employs delay change curves (DCCs) and uses targeted transistor sizing and/or buffer insertion. Based on a timing graph, a longest path capable of being shortened may be shortened by victim strengthening or aggressor weakening when a setup requirement time violation occurs and the path is capable of being shortened. The process is repeated based on an updated timing graph until the longest path is not capable of being further shortened, or there is no setup requirement time violation. Additionally, the path may be lengthened where a hold requirement time violation has occurred and the path is capable of being lengthened, by victim strengthening or aggressor weakening, until the path cannot be further lengthened or there is no hold requirement time violation. Victim strengthening is performed by altering the critical path, and aggressor weakening is performed by altering the non-critical path.
    Type: Grant
    Filed: June 10, 2003
    Date of Patent: September 19, 2006
    Inventor: Albert E. Casavant
  • Patent number: 6975976
    Abstract: Simulation continues to be the primary technique for functional validation of designs. It is important that simulation vectors be effective in targeting the types of bugs designers expect to find rather than some generic coverage metrics. The focus of this work is to generate property-specific testbenches that are targeted either at proving the correctness of a property or at finding a bug. It is based on performing property-specific analysis on iteratively less abstract models of the design in order to obtain interesting paths in the form of a Witness Graph, which is then targeted during simulation of the entire design. This testbench generation framework will form an integral part of a comprehensive verification system currently being developed.
    Type: Grant
    Filed: October 23, 2000
    Date of Patent: December 13, 2005
    Assignee: NEC Corporation
    Inventors: Albert E. Casavant, Aarti Gupta, Pranav Ashar
  • Publication number: 20030229873
    Abstract: A method and system of crosstalk mitigation in integrated circuits employs delay change curves (DCCs) and uses targeted transistor sizing and/or buffer insertion. Based on a timing graph, a longest path capable of being shortened may be shortened by victim strengthening or aggressor weakening when a setup requirement time violation occurs and the path is capable of being shortened. The process is repeated based on an updated timing graph until the longest path is not capable of being further shortened, or there is no setup requirement time violation. Additionally, the path may be lengthened where a hold requirement time violation has occurred and the path is capable of being lengthened, by victim strengthening or aggressor weakening, until the path cannot be further lengthened or there is no hold requirement time violation. Victim strengthening is performed by altering the critical path, and aggressor weakening is performed by altering the non-critical path.
    Type: Application
    Filed: June 10, 2003
    Publication date: December 11, 2003
    Applicant: NEC CORPORATION
    Inventor: Albert E. Casavant
  • Patent number: 6637014
    Abstract: A method and system of crosstalk mitigation in integrated circuits employs delay change curves (DCCs) and uses targeted transistor sizing and/or buffer insertion. Based on a timing graph, a longest path capable of being shortened may be shortened by victim strengthening or aggressor weakening when a setup requirement time violation occurs and the path is capable of being shortened. The process is repeated based on an updated timing graph until the longest path is not capable of being further shortened, or there is no setup requirement time violation. Additionally, the path may be lengthened where a hold requirement time violation has occurred and the path is capable of being lengthened, by victim strengthening or aggressor weakening, until the path cannot be further lengthened or there is no hold requirement time violation. Victim strengthening is performed by altering the critical path, and aggressor weakening is performed by altering the non-critical path.
    Type: Grant
    Filed: October 16, 2001
    Date of Patent: October 21, 2003
    Assignee: NEC Corporation
    Inventor: Albert E. Casavant
  • Patent number: 6594806
    Abstract: A method for performing timing analysis comprising inputting circuit timing information for a circuit, including temporal constraints between events of a desired circuit operation. A timing diagram representing the desired circuit operation, based on the circuit timing information is generater. All violated constraints within said timing diagram are identified. The method forces no violations of said violated constraints by designating the violated constraints as Non-Breakable (NB) constraints, such that a time difference from a source event to a destination event which defines said NB constraint is no less than a minimum bound and no more than a maximum bound of a linear constraint representing a timing requirement between the source and the destination events.
    Type: Grant
    Filed: June 7, 2000
    Date of Patent: July 15, 2003
    Assignee: NEC Corporation
    Inventor: Albert E. Casavant
  • Publication number: 20020166101
    Abstract: A method and system of crosstalk mitigation in integrated circuits employs delay change curves (DCCs) and uses targeted transistor sizing and/or buffer insertion. Based on a timing graph, a longest path capable of being shortened may be shortened by victim strengthening or aggressor weakening when a setup requirement time violation occurs and the path is capable of being shortened. The process is repeated based on an updated timing graph until the longest path is not capable of being further shortened, or there is no setup requirement time violation. Additionally, the path may be lengthened where a hold requirement time violation has occurred and the path is capable of being lengthened, by victim strengthening or aggressor weakening, until the path cannot be further lengthened or there is no hold requirement time violation. Victim strengthening is performed by altering the critical path, and aggressor weakening is performed by altering the non-critical path.
    Type: Application
    Filed: October 16, 2001
    Publication date: November 7, 2002
    Applicant: NEC USA, INC.
    Inventor: Albert E. Casavant
  • Patent number: 5175843
    Abstract: A computer-aided design method for restructuring computational networks to minimize latency and shim delay, suitable for use by a silicon compiler. Data-flow graphs for computational networks which use trees of operators, each performing associative and commutative combining of its respective imput operands to generate a respective output operand, are converted to data-flow graphs with multiple-input operators. Data-flow graphs with multiple-input operators, after being optimally scheduled, are converted to data-flow graphs which use trees of dual-input operators or of dual-input and three-input operators, those trees having minimum latency and shim delay associated with them. These data-flow graphs then have shim delay minimized in them, e.g. by being subjected to linear programming.
    Type: Grant
    Filed: October 30, 1989
    Date of Patent: December 29, 1992
    Assignee: General Electric Company
    Inventors: Albert E. Casavant, Richard I. Hartley