Patents by Inventor Lawrence Loh
Lawrence Loh 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).
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Patent number: 10204201Abstract: Disclosed are techniques for verifying an electronic design using hierarchical clock domain crossing verification techniques. These techniques identify an electronic design including a top hierarchy and one or more instances at a first child hierarchy below the top hierarchy. The electronic design may be decomposed into a top hierarchy block for the top hierarchy and one or more child blocks for the one or more instances. A plurality of data structures may be generated by separately processing the top hierarchy block and the one or more child blocks on one or more computing nodes. One or more clock domain crossing structures may be identified in the electronic design at least by integrating the plurality of data structures.Type: GrantFiled: June 30, 2016Date of Patent: February 12, 2019Assignee: Cadence Design Systems, Inc.Inventors: Lawrence Loh, Artur Melo Mota Costa, Breno Rodrigues Guimaraes, Fabiano Peixoto, Andrea Iabrudi Tavares
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Patent number: 9934410Abstract: A formal verification approach verifies data access and data propagation paths in a circuit design by proving the unreachability of path cover properties of the circuit design. A security path verification system receives an original circuit model of a circuit design, along with parameters identifying a first location within the circuit design that is a source of tainted data and a second location within the circuit design that is coupled to the first location. The security path verification system also receives a selection of portions of the circuit design to be excluded from the verification analysis. Using an abstracted version of the exclude portions, the security verification system generates a second circuit model of the circuit design for use in determining whether the tainted data can reach the second location from the first location within the circuit design.Type: GrantFiled: September 19, 2016Date of Patent: April 3, 2018Assignee: Cadence Design Systems, Inc.Inventors: Victor Markus Purri, Caio Araújo Teixeira Campos, Magnus Björk, Lawrence Loh, Claudionor Jose Nunes Coelho
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Patent number: 9922209Abstract: A formal verification approach verifies data access and data propagation paths in a circuit design by proving the unreachability of path cover properties of the circuit design. A security path verification system receives an original circuit model of a circuit design, along with parameters identifying a first location within the circuit design that is a source of tainted data and a second location within the circuit design that is coupled to the first location. The security path verification system also receives a selection of portions of the circuit design to be excluded from the verification analysis. Using an abstracted version of the exclude portions, the security verification system generates a second circuit model of the circuit design for use in determining whether the tainted data can reach the second location from the first location within the circuit design.Type: GrantFiled: September 19, 2016Date of Patent: March 20, 2018Assignee: Cadence Design Systems, Inc.Inventors: Victor Markus Purri, Caio Araújo Teixeira Campos, Magnus Björk, Lawrence Loh, Claudionor Jose Nunes Coelho
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Patent number: 9633151Abstract: Various mechanisms and approaches identify a first electronic design component at least by traversing at least a portion of the electronic design and generate a representation of the electronic design by interconnecting one or more duplicated electronic design components within the representation. The first electronic design component may include a destination electronic design component with a backward traversal of the electronic design. One or more fan-in electronic design components may be duplicated into the one or more duplicated electronic design components. One or more CDC effect models are automatically injected into the representation by adding the one or more CDC effect models along one or more paths in the representation. Proof results are generated at least via proving or disproving one or more checkers for the electronic design by verifying or simulating the representation with the one or more CDC effect models that are automatically injected into the representation.Type: GrantFiled: March 31, 2015Date of Patent: April 25, 2017Assignee: Cadence Design Systems, Inc.Inventors: Xiaoyang Sun, Marcus Vinicius da Mata Gomes, Andrea Iabrudi Tavares, Lawrence Loh, Fabiano Peixoto
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Patent number: 9449196Abstract: A formal verification approach verifies data access and data propagation paths in a circuit design by proving the unreachability of path cover properties of the circuit design. A security path verification system receives an original circuit model of a circuit design, along with parameters identifying a first location within the circuit design that is a source of tainted data and a second location within the circuit design that is coupled to the first location. The security path verification system also receives a selection of portions of the circuit design to be excluded from the verification analysis. Using an abstracted version of the exclude portions, the security verification system generates a second circuit model of the circuit design for use in determining whether the tainted data can reach the second location from the first location within the circuit design.Type: GrantFiled: April 22, 2013Date of Patent: September 20, 2016Assignee: Jasper Design Automation, Inc.Inventors: Victor Markus Purri, Caio Araújo Teixeira Campos, Magnus Björk, Lawrence Loh, Claudionor Jose Nunes Coelho
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Patent number: 9104824Abstract: A register transfer level (RTL) design is received which models a digital circuit in terms of the flow of digital signals. A power intent description is received which may include a description of power domains, identification of retention flops for each power domain, a list of isolation signals, and power switch definitions. A transformed RTL is produced accounting for functionality described in the power intent description. The transformed RTL includes flops designated as retention flops and non-retention flops. A retention flop module analyzes the flops to ensure that flops are properly designated as retention or non-retention flops. A verification module performs power aware sequential equivalence checking on various RTL and power intent descriptions to verify that RTL and power intent description outputs behave the same when accounting for power states.Type: GrantFiled: April 30, 2013Date of Patent: August 11, 2015Assignee: Jasper Design Automation, Inc.Inventors: Lawrence Loh, Barbara Jobstmann, Antonio Celso Caldeira, Jr., Jamil R. Mazzawi
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Patent number: 8954904Abstract: A register transfer level (RTL) design is received which models a digital circuit in terms of the flow of digital signals. A power intent description is received which may include a description of power domains, identification of retention flops for each power domain, a list of isolation signals, and power switch definitions. A transformed RTL is produced accounting for functionality described in the power intent description. The transformed RTL includes flops designated as retention flops and non-retention flops. A retention flop module analyzes the flops to ensure that flops are properly designated as retention or non-retention flops. A verification module performs power aware sequential equivalence checking on various RTL and power intent descriptions to verify that RTL and power intent description outputs behave the same when accounting for power states.Type: GrantFiled: April 30, 2013Date of Patent: February 10, 2015Assignee: Jasper Design Automation, Inc.Inventors: Lawrence Loh, Barbara Jobstmann, Antonio Celso Caldeira, Jr., Jamil R. Mazzawi
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Patent number: 8863049Abstract: The result of a property based formal verification analysis of a circuit design may include at least one counterexample for each property that is violated, which a user can use to debug the circuit design. To assist the user in this debugging process, a debugging tool applies one or more soft constraints to a counterexample trace that simplify the appearance of the trace when displayed as a waveform. The debugging tool thus facilitates a user's understanding of what parts of the counterexample trace are responsible for the property failure. Also described is a power analysis tool that increases the noise level of a trace for a circuit design in order to facilitate analysis of the circuit design's power characteristics.Type: GrantFiled: December 6, 2010Date of Patent: October 14, 2014Assignee: Jasper Design Automation, Inc.Inventors: Lars Lundgren, Ziyad Hanna, Chung-Wah Norris Ip, Kathryn Drews Kranen, Lawrence Loh
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Patent number: 8831925Abstract: An executable circuit design is used to generate waveforms, from which behaviors of the circuit are captured. The behaviors and various combinations thereof can then be saved in a database, along with descriptions and other metadata about them, thereby generating a behavioral index of the circuit design code. Behavioral indexing of circuit designs allows a user to maintain an indexed behavior database, track changes in behaviors as the circuit design's executable description evolves, and figure out how the executable description can be reused in different projects. When applied to digital design development, it facilities the current design and verification effort, as well as design reuse down the line.Type: GrantFiled: June 9, 2010Date of Patent: September 9, 2014Assignee: Jasper Design Automation, Inc.Inventors: Kathryn Drews Kranen, Chung-Wah Norris Ip, Rajeev Kumar Ranjan, Lawrence Loh, Beth C. Isaksen, Yann Alain Antonioli, Craig Franklin Deaton
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Patent number: 8731894Abstract: An executable circuit design is used to generate waveforms, from which behaviors of the circuit are captured. The behaviors and various combinations thereof can then be saved in a database, along with descriptions and other metadata about them, thereby generating a behavioral index of the circuit design code. Behavioral indexing of circuit designs allows a user to maintain an indexed behavior database, track changes in behaviors as the circuit design's executable description evolves, and figure out how the executable description can be reused in different projects. When applied to digital design development, it facilities the current design and verification effort, as well as design reuse down the line.Type: GrantFiled: September 14, 2012Date of Patent: May 20, 2014Assignee: Jasper Design Automation, Inc.Inventors: Kathryn Drews Kranen, Chung-Wah Norris Ip, Rajeev Kumar Ranjan, Lawrence Loh, Beth C. Isaksen, Yann Alain Antonioli, Craig Franklin Deaton
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Patent number: 8381148Abstract: A verification system determines proof of the absence of a deadlock condition or other data-transport property in a multi-system SoC using helper assertions derived from a transaction definition. The verification system receives the circuit design information along with a transaction definition for one or more ports of the SoC. Once specified, the transaction definition is instantiated into the full system or subsystem RTL, generating an expanded RTL and a deadlock property. Data flow through the RTL is analyzed to extract helper assertions describing how the data flowed through the RTL. Helper assertions are automatically extracted to aid in the verification of the absence of a deadlock condition. Using the helper assertions, the formal engine applies one or more techniques to formally analyze the circuit design to prove the absence of a deadlock condition.Type: GrantFiled: February 24, 2012Date of Patent: February 19, 2013Assignee: Jasper Design AutomationInventors: Lawrence Loh, Xiaoyang Sun
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Patent number: 7647572Abstract: A counter abstraction tool generates an abstraction model for one or more counters in a circuit design for use with a formal verification system. The tool detects the presence of a counter in a circuit design, identifies one or more special values for the counter, and creates an abstraction for the counter. The tool can automatically perform the abstraction, guide a user in configuring the appropriate abstraction for the counter, or perform a combination of automatic and manual abstraction. The tool may further accommodate related counters.Type: GrantFiled: September 6, 2007Date of Patent: January 12, 2010Assignee: Jasper Design Automation, Inc.Inventors: Chung-Wah Norris Ip, Lawrence Loh, Vigyan Singhal, Howard Wong-Toi
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Patent number: 7437694Abstract: A system and method for identifying, for a selected signal, those signals whose value is relevantly determined based upon a value of the selected signal, where a set of signals to be examined is identified as those signals that satisfy one or more of the following criteria: (1) they are RTL load signals of the selected signal, (2) they are RTL load signals that are also in an analysis region, (3) they are RTL load signals within the analysis region that also contribute to a proof target, and/or 4) they are RTL load signals that contribute to the proof target.Type: GrantFiled: February 22, 2005Date of Patent: October 14, 2008Assignee: Jasper Design AutomationInventors: Lawrence Loh, Chung-Wah Norris Ip, Soe Myint
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Patent number: 7418678Abstract: A counter abstraction tool generates an abstraction model for one or more counters in a circuit design for use with a formal verification system. The tool detects the presence of a counter in a circuit design, identifies one or more special values for the counter, and creates an abstraction for the counter. The tool can automatically perform the abstraction, guide a user in configuring the appropriate abstraction for the counter, or perform a combination of automatic and manual abstraction. The tool may further accommodate related counters.Type: GrantFiled: July 29, 2004Date of Patent: August 26, 2008Assignee: Jasper Design Automation, Inc.Inventors: Chung-Wah N Ip, Lawrence Loh, Vigyan Singhal, Howard Wong-Toi
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Patent number: 7237208Abstract: To perform functional verification of a digital design that includes one or more datapaths, a formal verification system includes a datapath abstraction tool. The datapath abstraction tool detects a datapath in a circuit design and performs an appropriate abstraction of the datapath. The tool may also deduce datapath elements from identified ones as well as link the abstractions of particular datapath elements. The abstraction tool then passes the circuit design with the abstraction to the verification software to simplifying the formal verification process.Type: GrantFiled: April 5, 2004Date of Patent: June 26, 2007Assignee: Jasper Design Automation, Inc.Inventors: Chung-Wah N. Ip, Lawrence Loh, Howard Wong-Toi, Harry D. Foster
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Patent number: 7159198Abstract: The present invention is directed to a system and a method for verifying properties of a circuit model while providing information to help the user manually modify a design analysis region and/or environmental constraints. While conventional systems attempt to substantially automate the entire formal verification process, the present invention iteratively provides information to the user about the cost and effect of changes to the environmental constraints and the analysis region. This information enables the user to weigh the effectiveness and efficiency of one or more modifications to the design analysis area and/or to the environmental constraints (assumptions). The information provided to the user can help a user compare a variety of alternative modifications in order to select the modifications that are efficient and effective.Type: GrantFiled: December 24, 2003Date of Patent: January 2, 2007Assignee: Jasper Design AutomationInventors: Chung-Wah Norris Ip, Lawrence Loh, Vigyan Singhal, Howard Wong-Toi, Soe Myint
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Publication number: 20030061341Abstract: A medium interface is revealed for connection between an Ethernet LAN controller without a physical (PHY) layer, and other network devices having different kinds of ports, including media independent interface (MII), serial media independent interface (SMII) and gigabit media independent interface (GMII). The interface makes possible a fast, efficient and inexpensive method to test, verify and emulate networks of integrated circuits before silicon is cast, that is, before an application specific integrated circuit (ASIC) is manufactured. The method also allows full test case coverage with high layer protocols.Type: ApplicationFiled: September 26, 2001Publication date: March 27, 2003Applicant: Infineon Technologies North America Corp.Inventors: Lawrence Loh, Nicolas Mauget