Patents by Inventor An Ly

An Ly 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.
  • Patent number: 8271918
    Abstract: Methods and apparatus for performing automated formal clock domain crossing verification on a device are detailed. In various implementations of the invention, a device may be analyzed, wherein the clock domain crossing boundaries are identified. Subsequently, a formal clock domain crossing verification method may be applied to the identified clock domain crossing boundaries, resulting in clock domain crossing assertions being identified. After which the identified assertions may be promoted for post clock domain crossing analysis. With various implementations of the invention, a formal clock domain crossing method is provided, wherein the device components near an identified clock domain crossing are extracted. Assertions may then be synthesized and verified based upon the extracted components. Various implementations of the invention provide for clock domain crossing verification to be performed iteratively, wherein a larger and larger selection of the device is extracted during formal verification.
    Type: Grant
    Filed: September 14, 2009
    Date of Patent: September 18, 2012
    Assignee: Mentor Graphics Corporation
    Inventors: Ka-Kei Kwok, Bing Li, Tai An Ly, Rojer Raji Sabbagh
  • 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.
  • Publication number: 20100199244
    Abstract: Methods and apparatus for performing automated formal clock domain crossing verification on a device are detailed. In various implementations of the invention, a device may be analyzed, wherein the clock domain crossing boundaries are identified. Subsequently, a formal clock domain crossing verification method may be applied to the identified clock domain crossing boundaries, resulting in clock domain crossing assertions being identified. After which the identified assertions may be promoted for post clock domain crossing analysis. With various implementations of the invention, a formal clock domain crossing method is provided, wherein the device components near an identified clock domain crossing are extracted. Assertions may then be synthesized and verified based upon the extracted components. Various implementations of the invention provide for clock domain crossing verification to be performed iteratively, wherein a larger and larger selection of the device is extracted during formal verification.
    Type: Application
    Filed: September 14, 2009
    Publication date: August 5, 2010
    Inventors: Ka-Kei Kwok, Bing Li, Tai An Ly, Rojer Raji Sabbagh
  • 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
  • Publication number: 20060017953
    Abstract: This disclosure provides a system and method for summarizing jobs for a user group. In one embodiment, a job manager is operable to invoke a job filter. The job filter is compatible with a plurality of operating environments. One or more properties of a first job associated with a first of the plurality of operating environments is identified. One or more properties of a second job associated with a second of the plurality of operating environments is identified. The first operating environment and the second operating environment are heterogeneous. The identified properties of the first job and the identified properties of the second job are compared to the job filter to select jobs for a user group.
    Type: Application
    Filed: July 20, 2005
    Publication date: January 26, 2006
    Inventors: An Ly, Arun Padmanabhan, Edward Chen
  • Publication number: 20060017975
    Abstract: This disclosure provides a system and method for summarizing jobs for a user group. In one embodiment, a job manager is operable to identify a state of a first job, the first job associated with a first job scheduler. A state of a second job is identified. The second job is associated with a second job scheduler. The first job scheduler and the second job scheduler are heterogeneous. A summary of information associated with at least the first job scheduler and the second job scheduler is determined using, at least in part, the first job state and the second job state. The summary is presented to a user though a dashboard.
    Type: Application
    Filed: July 20, 2005
    Publication date: January 26, 2006
    Inventors: An Ly, Arun Padmanabhan, Edward Chen
  • Publication number: 20060017969
    Abstract: A system and method for managing jobs are provided. A job manager is operable to normalize a command submitted by a user. The job manager then executes a first job associated with a first operating environment in response to the normalized command and executes a second job associated with a second operating environment in response to the normalized command. The first operating environment and the second operating environment are heterogeneous.
    Type: Application
    Filed: July 20, 2005
    Publication date: January 26, 2006
    Inventors: An Ly, Arun Padmanabhan, Edward Chen
  • Publication number: 20060017954
    Abstract: This disclosure provides a system and method for normalizing job properties. In one embodiment, a job manager is operable to identify a property of a job, with the job being associated with an operating environment. The job manager is further operable to normalize the property of the job and present the normalized property of the job to a user.
    Type: Application
    Filed: July 20, 2005
    Publication date: January 26, 2006
    Inventors: An Ly, Arun Padmanabhan, Edward Chen
  • Publication number: 20060020942
    Abstract: This disclosure provides a system and method for summarizing jobs for a user group. In one embodiment, a job manager is operable to invoke an alert filter. The alert filter is compatible with a plurality operating environments. One or more properties of a first job associated with a first operating environment is identified. One or more properties of a second job associated with a second operating environment is identified. The first operating environment and the second operating environment are heterogeneous. A first alert object is generated in response to a first match between the alert filter and the identified properties of the first job. A second alert object is generated in response to a second match between the alert filter and the identified properties of the second job.
    Type: Application
    Filed: July 20, 2005
    Publication date: January 26, 2006
    Inventors: An Ly, Arun Padmanabhan, Edward Chen
  • 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