Patents by Inventor Lawrence A. Curtis

Lawrence A. Curtis 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: 8914761
    Abstract: A circuit design that contains at least two clock domains is simulated using a novel system and method for injecting the effects of metastability. The system includes detectors for detecting, during simulation, when a clock in a transmit clock domain and a clock in a receive clock domain are aligned and when the input of a register receiving a clock-domain-crossing signal is changing. The system includes coverage monitors for measuring, during simulation, statistics related to metastability injection. The system accurately models the effects of metastability by, at appropriate times during simulation, pseudo-randomly inverting outputs of registers receiving clock-domain-crossing signals. By accurately modeling the effects of metastability, errors in the circuit design can be detected while simulating a pre-existing simulation test. The simulation with metastability effects injection is repeatable and requires no modification of pre-existing RTL design files or simulation test files.
    Type: Grant
    Filed: May 6, 2013
    Date of Patent: December 16, 2014
    Assignee: Mentor Graphics Corporation
    Inventors: Tai An Ly, Ka Kei Kwok, Vijaya Vardhan Gupta, Lawrence Curtis Widdoes, Jr.
  • Publication number: 20130246985
    Abstract: A circuit design that contains at least two clock domains is simulated using a novel system and method for injecting the effects of metastability. The system includes detectors for detecting, during simulation, when a clock in a transmit clock domain and a clock in a receive clock domain are aligned and when the input of a register receiving a clock-domain-crossing signal is changing. The system includes coverage monitors for measuring, during simulation, statistics related to metastability injection. The system accurately models the effects of metastability by, at appropriate times during simulation, pseudo-randomly inverting outputs of registers receiving clock-domain-crossing signals. By accurately modeling the effects of metastability, errors in the circuit design can be detected while simulating a pre-existing simulation test. The simulation with metastability effects injection is repeatable and requires no modification of pre-existing RTL design files or simulation test files.
    Type: Application
    Filed: May 6, 2013
    Publication date: September 19, 2013
    Applicant: Mentor Graphics Corporation
    Inventors: Tai An Ly, Ka Kei Kwok, Vijaya Vardhan Gupta, Lawrence Curtis Widdoes, JR.
  • Patent number: 8438516
    Abstract: A circuit design that contains at least two clock domains is simulated using a novel system and method for injecting the effects of metastability. The system includes detectors for detecting, during simulation, when a clock in a transmit clock domain and a clock in a receive clock domain are aligned and when the input of a register receiving a clock-domain-crossing signal is changing. The system includes coverage monitors for measuring, during simulation, statistics related to metastability injection. The system accurately models the effects of metastability by, at appropriate times during simulation, pseudo-randomly inverting outputs of registers receiving clock-domain-crossing signals. By accurately modeling the effects of metastability, errors in the circuit design can be detected while simulating a pre-existing simulation test. The simulation with metastability effects injection is repeatable and requires no modification of pre-existing RTL design files or simulation test files.
    Type: Grant
    Filed: May 4, 2010
    Date of Patent: May 7, 2013
    Assignee: Mentor Graphics Corporation
    Inventors: Tai An Ly, Ka Kei Kwok, Vijaya Vardhan Gupta, Lawrence Curtis Widdoes, Jr.
  • Publication number: 20100287524
    Abstract: A circuit design that contains at least two clock domains is simulated using a novel system and method for injecting the effects of metastability. The system includes detectors for detecting, during simulation, when a clock in a transmit clock domain and a clock in a receive clock domain are aligned and when the input of a register receiving a clock-domain-crossing signal is changing. The system includes coverage monitors for measuring, during simulation, statistics related to metastability injection. The system accurately models the effects of metastability by, at appropriate times during simulation, pseudo-randomly inverting outputs of registers receiving clock-domain-crossing signals. By accurately modeling the effects of metastability, errors in the circuit design can be detected while simulating a pre-existing simulation test. The simulation with metastability effects injection is repeatable and requires no modification of pre-existing RTL design files or simulation test files.
    Type: Application
    Filed: May 4, 2010
    Publication date: November 11, 2010
    Inventors: Tai An Ly, Ka Kei Kwok, Vijaya Vardhan Gupta, Lawrence Curtis Widdoes, JR.
  • Patent number: 7712062
    Abstract: A circuit design that contains at least two clock domains is simulated using a novel system and method for injecting the effects of metastability. The system includes detectors for detecting, during simulation, when a clock in a transmit clock domain and a clock in a receive clock domain are aligned and when the input of a register receiving a clock-domain-crossing signal is changing. The system includes coverage monitors for measuring, during simulation, statistics related to metastability injection. The system accurately models the effects of metastability by, at appropriate times during simulation, pseudo-randomly inverting outputs of registers receiving clock-domain-crossing signals. By accurately modeling the effects of metastability, errors in the circuit design can be detected while simulating a pre-existing simulation test. The simulation with metastability effects injection is repeatable and requires no modification of pre-existing RTL design files or simulation test files.
    Type: Grant
    Filed: February 11, 2008
    Date of Patent: May 4, 2010
    Inventors: Tai An Ly, Ka Kie Kwok, Vijaya Vardhan Gupta, Lawrence Curtis Widdoes, Jr.
  • Patent number: 7478028
    Abstract: A programmed computer searches for functional defects in a description of a circuit undergoing functional verification in the following manner. The programmed computer simulates the functional behavior of the circuit in response to a test vector, automatically restores the state of the simulation without causing the simulation to pass through a reset state, and then simulates the functional behavior of the circuit in response to another test vector. A predetermined rule can be used to identify test vectors to be simulated, and the predetermined rule can depend upon a measure of functional verification, including the number of times during simulation when a first state transition is performed by a first-controller at the same time as a second state transition is performed by a second controller. During simulation of the test vectors, manually generated tests or automatically generated checkers can monitor portions of the circuit for defective behavior.
    Type: Grant
    Filed: January 12, 2005
    Date of Patent: January 13, 2009
    Inventors: Chian-Min Richard Ho, Robert Kristianto Mardjuki, David Lansing Dill, Jing Chyuarn Lin, Ping Fai Yeung, Paul II Estrada, Jean-Charles Giomi, Tai An Ly, Kalyana C. Mulam, Lawrence Curtis Widdoes, Jr., Paul Andrew Wilcox
  • Patent number: 7454728
    Abstract: During verification of a description of a circuit containing a pre-determined assertion, in order to detect incorrect behavior of the circuit that may be caused by metastability occurring in signals that cross clock domains (“CDC” signals) in the circuit, the description of the circuit is automatically transformed by addition of circuitry to inject the effects of metastability into the CDC signals. The transformed description containing the circuitry to inject metastability is verified in the normal manner. Certain embodiments analyze the transformed description using a model checking method to determine a stimulus sequence that will cause the pre-determined assertion to be violated. The transformed circuit is then simulated in some embodiments, using the stimulus sequence from model checking, and an incorrect behavior of the circuit due to metastability is displayed, for diagnosis by the circuit designer. The circuit designer may revise the circuit description and iterate as noted above.
    Type: Grant
    Filed: June 7, 2007
    Date of Patent: November 18, 2008
    Inventors: Tai An Ly, Ka Kei Kwok, Vijaya Vardhan Gupta, Ross Andrew Andersen, Ping Fai Yeung, Neil Patrick Hand, Lawrence Curtis Widdoes, Jr.
  • Publication number: 20080134115
    Abstract: A circuit design that contains at least two clock domains is simulated using a novel system and method for injecting the effects of metastability. The system includes detectors for detecting, during simulation, when a clock in a transmit clock domain and a clock in a receive clock domain are aligned and when the input of a register receiving a clock-domain-crossing signal is changing. The system includes coverage monitors for measuring, during simulation, statistics related to metastability injection. The system accurately models the effects of metastability by, at appropriate times during simulation, pseudo-randomly inverting outputs of registers receiving clock-domain-crossing signals. By accurately modeling the effects of metastability, errors in the circuit design can be detected while simulating a pre-existing simulation test. The simulation with metastability effects injection is repeatable and requires no modification of pre-existing RTL design files or simulation test files.
    Type: Application
    Filed: February 11, 2008
    Publication date: June 5, 2008
    Applicant: MENTOR GRAPHICS CORPORATION
    Inventors: Tai An Ly, Ka Kie Kwok, Vijaya Vardhan Gupta, Lawrence Curtis Widdoes
  • Patent number: 7356789
    Abstract: A circuit design that contains at least two clock domains is simulated using a novel system and method for injecting the effects of metastability. The system includes detectors for detecting, during simulation, when a clock in a transmit clock domain and a clock in a receive clock domain are aligned and when the input of a register receiving a clock-domain-crossing signal is changing. The system includes coverage monitors for measuring, during simulation, statistics related to metastability injection. The system accurately models the effects of metastability by, at appropriate times during simulation, pseudo-randomly inverting outputs of registers receiving clock-domain-crossing signals. By accurately modeling the effects of metastability, errors in the circuit design can be detected while simulating a pre-existing simulation test. The simulation with metastability effects injection is repeatable and requires no modification of pre-existing RTL design files or simulation test files.
    Type: Grant
    Filed: May 27, 2005
    Date of Patent: April 8, 2008
    Inventors: Tai An Ly, Ka Kei Kwok, Vijaya Vardhan Gupta, Lawrence Curtis Widdoes, Jr.
  • Patent number: 7243322
    Abstract: During verification of a description of a circuit containing a pre-determined assertion, in order to detect incorrect behavior of the circuit that may be caused by metastability occurring in signals that cross clock domains (“CDC” signals) in the circuit, the description of the circuit is automatically transformed by addition of circuitry to inject the effects of metastability into the CDC signals. The transformed description containing the circuitry to inject metastability is verified in the normal manner. Certain embodiments analyze the transformed description using a model checking method to determine a stimulus sequence that will cause the pre-determined assertion to be violated. The transformed circuit is then simulated in some embodiments, using the stimulus sequence from model checking, and an incorrect behavior of the circuit due to metastability is displayed, for diagnosis by the circuit designer. The circuit designer may revise the circuit description and iterate as noted above.
    Type: Grant
    Filed: June 1, 2004
    Date of Patent: July 10, 2007
    Inventors: Tai An Ly, Ka Kei Kwok, Vijaya Vardhan Gupta, Ross Andrew Ander, Ping Fai Yeung, Neil Patrick Hand, Lawrence Curtis Widdoes, Jr.
  • Patent number: 7007249
    Abstract: A programmed computer generates descriptions of circuits (called “checkers”) that flag functional defects in a description of a circuit undergoing functional verification. The programmed computer automatically converts the circuit's description into a graph, automatically examines the graph for instances of a predetermined arrangement of nodes and connections, and automatically generates instructions that flag a behavior of a device represented by the instance in conformance with a known defective behavior. The checkers can be used during simulation or emulation of the circuit, or during operation of the circuit in a semiconductor die. The circuit's description can be in Verilog or VHDL and the automatically generated checkers can also be described in Verilog or VHDL. Therefore, the checkers can co-simulate with the circuit, monitoring the simulated operation of the circuit and flagging defective behavior.
    Type: Grant
    Filed: January 20, 2003
    Date of Patent: February 28, 2006
    Inventors: Tai An Ly, Jean-Charles Giomi, Kalyana C. Mulam, Paul Andrew Wilcox, David Lansing Dill, Paul II Estrada, Chian-Min Richard Ho, Jing Chyuarn Lin, Robert Kristianto Mardjuki, Lawrence Curtis Widdoes, Jr., Ping Fai Yeung
  • Patent number: 6885983
    Abstract: A programmed computer searches for functional defects in a description of a circuit undergoing functional verification in the following manner. The programmed computer simulates the functional behavior of the circuit in response to a test vector, automatically restores the state of the simulation without causing the simulation to pass through a reset state, and then simulates the functional behavior of the circuit in response to another test vector. A predetermined rule can be used to identify test vectors to be simulated, and the predetermined rule can depend upon a measure of functional verification, including the number of times during simulation when a first state transition is performed by a first controller at the same time as a second state transition is performed by a second controller. During simulation of the test vectors, manually generated tests or automatically generated checkers can monitor portions of the circuit for defective behavior.
    Type: Grant
    Filed: May 4, 2001
    Date of Patent: April 26, 2005
    Assignee: Mentor Graphics Corporation
    Inventors: Chian-Min Richard Ho, Robert Kristianto Mardjuki, David Lansing Dill, Jing Chyuarn Lin, Ping Fai Yeung, Paul Il Estrada, Jean-Charles Giomi, Tai An Ly, Kalyana C. Mulam, Lawrence Curtis Widdoes, Jr., Paul Andrew Wilcox
  • Publication number: 20030200515
    Abstract: A programmed computer generates descriptions of circuits (called “checkers”) that flag functional defects in a description of a circuit undergoing functional verification. The programmed computer automatically converts the circuit's description into a graph, automatically examines the graph for instances of a predetermined arrangement of nodes and connections, and automatically generates instructions that flag a behavior of a device represented by the instance in conformance with a known defective behavior. The checkers can be used during simulation or emulation of the circuit, or during operation of the circuit in a semiconductor die. The circuit's description can be in Verilog or VHDL and the automatically generated checkers can also be described in Verilog or VHDL. Therefore, the checkers can co-simulate with the circuit, monitoring the simulated operation of the circuit and flagging defective behavior.
    Type: Application
    Filed: January 20, 2003
    Publication date: October 23, 2003
    Applicant: 0-In Design automation Inc.
    Inventors: Tai An Ly, Jean-Charles Giomi, Kalyana C. Mulam, Paul Andrew Wilcox, David Lansing Dill, Paul Ii Estrada, Chian-Min Richard Ho, Jing Chyuarn Lin, Robert Kristianto Mardjuki, Lawrence Curtis Widdoes, Ping Fai Yeung
  • Patent number: 6609229
    Abstract: A programmed computer generates descriptions of circuits (called “checkers”) that flag functional defects in a description of a circuit undergoing functional verification. The programmed computer automatically converts the circuit's description into a graph, automatically examines the graph for instances of a predetermined arrangement of nodes and connections, and automatically generates instructions that flag a behavior of a device represented by the instance in conformance with a known defective behavior. The checkers can be used during simulation or emulation of the circuit, or during operation of the circuit in a semiconductor die The circuit's description can be in Verilog or VHDL and the automatically generated checkers can also be described in Verilog or VHDL. Therefore, the checkers can co-simulate with the circuit, monitoring the simulated operation of the circuit and flagging detective behavior.
    Type: Grant
    Filed: August 9, 2000
    Date of Patent: August 19, 2003
    Assignee: O-In Design Automation, Inc.
    Inventors: Tai An Ly, Jean-Charles Giomi, Kalyana C. Mulam, Paul Andrew Wilcox, David Lansing Dill, Paul Estrada, II, Chian-Min Richard Ho, Jing Chyuarn Lin, Robert Kristianto Mardjuki, Lawrence Curtis Widdoes, Jr., Ping Fai Yeung
  • Publication number: 20020169027
    Abstract: A golf hole for a miniature golf course is formed of a plurality of components, these components being divided into three distinct types: platform base panels, side rails, and riser feet. Each platform base panel is constructed or molded with attachments for side rails and riser feet. The riser feet are first attached to platform base panels. The platform base panels are laid out in any desired hole configuration within the parameters of the invention, one platform base panel containing the golf cup. Carpet or artificial turf, continuous or in sections, is then cut to fit and laid over platform base panels. The side rails and metal start rails are placed over the edge of the carpet along the perimeter of the hole and secured to the platform base panels. Obstacles may be bolted to the platform base panels at various points on the putting surface.
    Type: Application
    Filed: May 11, 2002
    Publication date: November 14, 2002
    Inventor: Lawrence Curtis Fowler
  • Patent number: 6469776
    Abstract: A method is provided for transferring dye from a dye imbibed matrix film to a receiver film for producing a dye transfer print of a motion picture print. A dye imbibed matrix film and a receiver film are superimposed together in precise registration on a seating apparatus, e.g., a pin belt, to create a two-film sandwich. The two-film sandwich is stripped from the seating apparatus before completing dye transfer, and dye transfer from the matrix film to the receiver film is completed along a pinless, substantially rectilinear film path while maintaining the two-film sandwich in precise registration. For example, a transfer cabinet may be provided that includes a plurality of rollers having a predetermined relationship to one another and defining the substantially rectilinear film path, and the two-film sandwich may be directed along the film path to complete dye transfer.
    Type: Grant
    Filed: June 15, 2001
    Date of Patent: October 22, 2002
    Assignee: Technicolor, Inc.
    Inventors: Ronald W. Jarvis, Richard J. Goldberg, Frank J. Ricotta, Ronald W. Corke, Lawrence A. Curtis, Steven Garlick, David M. Gilmartin
  • Publication number: 20020018196
    Abstract: A system for producing prints of a professional motion picture film by dye transfer, including a roll tank, a pin belt, and a transfer cabinet. A dye imbibed matrix film and blank film are superimposed together in a predetermined registration by rollers in the roll tank, creating a two-film sandwich, which is directed onto the pin belt. The pin belt includes a plurality of pins traveling in an orbital path, which detachably engage the two-film sandwich, thereby directing the two-film sandwich along a portion of the orbital path. The transfer cabinet includes a plurality of relatively large diameter rollers in a predetermined relationship to one another, and an elevator mechanism for adjusting the predetermined relationship. The rollers define a substantially rectilinear film path along which the two-film sandwich from the pin belt is directed. The film path has a length sufficient to allow complete dye transfer to occur at high drive speeds within the transfer cabinet.
    Type: Application
    Filed: June 15, 2001
    Publication date: February 14, 2002
    Applicant: Technicolor, Inc.
    Inventors: Ronald W. Jarvis, Richard J. Goldberg, Frank J. Ricotta, Ronald W. Corke, Lawrence A. Curtis, Steven Garlick, David M. Gilmartin
  • Patent number: 6327027
    Abstract: A system for producing prints of a professional motion picture film by dye transfer, including a roll tank, a pin belt, and a transfer cabinet. A dye imbibed matrix film and blank film are superimposed together in a predetermined registration by rollers in the roll tank, creating a two-film sandwich, which is directed onto the pin belt. The pin belt includes a plurality of pins traveling in an orbital path, which detachably engage the two-film sandwich, thereby directing the two-film sandwich along a portion of the orbital path. The transfer cabinet includes a plurality of relatively large diameter rollers in a predetermined relationship to one another, and an elevator mechanism for adjusting the predetermined relationship. The rollers define a substantially rectilinear film path along which the two-film sandwich from the pin belt is directed. The film path has a length sufficient to allow complete dye transfer to occur at high drive speeds within the transfer cabinet.
    Type: Grant
    Filed: July 24, 2000
    Date of Patent: December 4, 2001
    Assignee: Technicolor, Inc.
    Inventors: Ronald W. Jarvis, Richard J. Goldberg, Frank J. Ricotta, Ronald W. Corke, Lawrence A. Curtis, Steven Garlick, David M. Gilmartin
  • Patent number: 6292765
    Abstract: A programmed computer searches for functional defects in a description of a circuit undergoing functional verification in the following manner. The programmed computer simulates the functional behavior of the circuit in response to a test vector, automatically restores the state of the simulation without causing the simulation to pass through a reset state, and then simulates the functional behavior of the circuit in response to another test vector. A predetermined rule can be used to identify test vectors to be simulated, and the predetermined rule can depend upon a measure of functional verification, including the number of times during simulation when a first state transition is performed by a first controller at the same time as a second state transition is performed by a second controller. During simulation of the test vectors, manually generated tests or automatically generated checkers can monitor portions of the circuit for defective behavior.
    Type: Grant
    Filed: October 20, 1997
    Date of Patent: September 18, 2001
    Assignee: O-In Design Automation
    Inventors: Chian-Min Richard Ho, Robert Kristianto Mardjuki, David Lansing Dill, Jing Chyuarn Lin, Ping Fai Yeung, Paul II Estrada, Jean-Charles Giomi, Tai An Ly, Kalyana C. Mulam, Lawrence Curtis Widdoes, Jr., Paul Andrew Wilcox
  • Patent number: 6175946
    Abstract: A programmed computer generates descriptions of circuits (called “checkers”) that flag functional defects in a description of a circuit undergoing functional verification. The programmed computer automatically converts the circuit's description into a graph, automatically examines the graph for instances of a predetermined arrangement of nodes and connections, and automatically generates instructions that flag a behavior of a device represented by the instance in conformance with a known defective behavior. The checkers can be used during simulation or emulation of the circuit, or during operation of the circuit in a semiconductor die. The circuit's description can be in Verilog or VHDL and the automatically generated checkers can also be described in Verilog or VHDL. Therefore, the checkers can co-simulate with the circuit, monitoring the simulated operation of the circuit and flagging defective behavior.
    Type: Grant
    Filed: October 20, 1997
    Date of Patent: January 16, 2001
    Assignee: O-IN Design Automation
    Inventors: Tai An Ly, Jean-Charles Giomi, Kalyana C. Mulam, Paul Andrew Wilcox, David Lansing Dill, Paul Estrada, II, Chian-Min Richard Ho, Jing Chyuarn Lin, Robert Kristianto Mardjuki, Lawrence Curtis Widdoes, Jr., Ping Fai Yeung