Patents by Inventor Pradeep K. Nalla
Pradeep K. Nalla 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: 10394987Abstract: Aspects of the present invention include methods, systems and computer program products. The method includes a processor providing a netlist indicative of connectivity and functional states of components of an integrated circuit design; iteratively searching through the netlist at a selected depth to locate errors within the netlist by a plurality of trials, each of the plurality of trials having a plurality of iterations; adaptively adjusting the selected depth depending on any errors within the netlist being located, the selected depth increasing over time from an initial value as between the plurality of iterations; and adaptively adjusting an amount of coverage of the netlist depending on any errors within the netlist being located, the amount of coverage of the netlist decreasing over time from an initial amount as between the plurality of iterations.Type: GrantFiled: March 21, 2017Date of Patent: August 27, 2019Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Jason R. Baumgartner, Raj K. Gajavelly, Hari Mony, Pradeep K. Nalla
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Patent number: 10210296Abstract: Aspects of the present invention include methods, systems and computer program products. The method includes a processor providing a netlist indicative of connectivity and functional states of components of an integrated circuit design; iteratively searching through the netlist at a selected depth to locate errors within the netlist by a plurality of trials, each of the plurality of trials having a plurality of iterations; adaptively adjusting the selected depth depending on any errors within the netlist being located, the selected depth increasing over time from an initial value as between the plurality of iterations; and adaptively adjusting an amount of coverage of the netlist depending on any errors within the netlist being located, the amount of coverage of the netlist decreasing over time from an initial amount as between the plurality of iterations.Type: GrantFiled: October 24, 2017Date of Patent: February 19, 2019Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Jason R. Baumgartner, Raj K. Gajavelly, Hari Mony, Pradeep K. Nalla
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Publication number: 20180276317Abstract: Aspects of the present invention include methods, systems and computer program products. The method includes a processor providing a netlist indicative of connectivity and functional states of components of an integrated circuit design; iteratively searching through the netlist at a selected depth to locate errors within the netlist by a plurality of trials, each of the plurality of trials having a plurality of iterations; adaptively adjusting the selected depth depending on any errors within the netlist being located, the selected depth increasing over time from an initial value as between the plurality of iterations; and adaptively adjusting an amount of coverage of the netlist depending on any errors within the netlist being located, the amount of coverage of the netlist decreasing over time from an initial amount as between the plurality of iterations.Type: ApplicationFiled: March 21, 2017Publication date: September 27, 2018Inventors: Jason R. Baumgartner, Raj K. Gajavelly, Hari Mony, Pradeep K. Nalla
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Publication number: 20180276318Abstract: Aspects of the present invention include methods, systems and computer program products. The method includes a processor providing a netlist indicative of connectivity and functional states of components of an integrated circuit design; iteratively searching through the netlist at a selected depth to locate errors within the netlist by a plurality of trials, each of the plurality of trials having a plurality of iterations; adaptively adjusting the selected depth depending on any errors within the netlist being located, the selected depth increasing over time from an initial value as between the plurality of iterations; and adaptively adjusting an amount of coverage of the netlist depending on any errors within the netlist being located, the amount of coverage of the netlist decreasing over time from an initial amount as between the plurality of iterations.Type: ApplicationFiled: October 24, 2017Publication date: September 27, 2018Inventors: Jason R. Baumgartner, Raj K. Gajavelly, Hari Mony, Pradeep K. Nalla
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Patent number: 10078716Abstract: Embodiments herein describe a verification process that identifies unate primary inputs in input paths of a property gate. A property gate is logic inserted in a hardware design represented by a netlist which is used to verify the design. Before performing the verification process, a computing system evaluates the netlist to identify the primary inputs in the input paths of the property gate and whether these primary inputs are unate or binate. To do so, in one embodiment, the computing system sets the output of the property gate in an error state and then traverses the input paths of the property gate to identify the values of the logic in the inputs paths that would result in the property gate being in the error state. Based on these polarities, the system can identify the unate and binate primary inputs.Type: GrantFiled: May 3, 2016Date of Patent: September 18, 2018Assignee: International Business Machines CorporationInventors: Jason R. Baumgartner, Raj K. Gajavelly, Alexander Ivrii, Pradeep K. Nalla
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Patent number: 10073938Abstract: Disclosed aspects relate to verifying an integrated circuit design. A set of design constraints may be received with respect to a verification process for the integrated circuit design. Based on the set of design constraints, a constraint model may be constructed. A new global constraint may be determined using the constraint model. The new global constraint may be used to process the verification process for the integrated circuit design.Type: GrantFiled: June 29, 2016Date of Patent: September 11, 2018Assignee: International Business Machines CorporationInventors: Anand B. Arunagiri, Raj K. Gajavelly, Sujeet Kumar, Pradeep K. Nalla
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Patent number: 9922153Abstract: Embodiments herein describe a verification process that identifies unate primary inputs in input paths of a property gate. A property gate is logic inserted in a hardware design represented by a netlist which is used to verify the design. Before performing the verification process, a computing system evaluates the netlist to identify the primary inputs in the input paths of the property gate and whether these primary inputs are unate or binate. To do so, in one embodiment, the computing system sets the output of the property gate in an error state and then traverses the input paths of the property gate to identify the values of the logic in the inputs paths that would result in the property gate being in the error state. Based on these polarities, the system can identify the unate and binate primary inputs.Type: GrantFiled: May 3, 2016Date of Patent: March 20, 2018Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Jason R. Baumgartner, Raj K. Gajavelly, Alexander Ivrii, Pradeep K. Nalla
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Publication number: 20180004879Abstract: Disclosed aspects relate to verifying an integrated circuit design. A set of design constraints may be received with respect to a verification process for the integrated circuit design. Based on the set of design constraints, a constraint model may be constructed. A new global constraint may be determined using the constraint model. The new global constraint may be used to process the verification process for the integrated circuit design.Type: ApplicationFiled: June 29, 2016Publication date: January 4, 2018Inventors: Anand B. Arunagiri, Raj K. Gajavelly, Sujeet Kumar, Pradeep K. Nalla
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Publication number: 20170323044Abstract: Embodiments herein describe a verification process that identifies unate primary inputs in input paths of a property gate. A property gate is logic inserted in a hardware design represented by a netlist which is used to verify the design. Before performing the verification process, a computing system evaluates the netlist to identify the primary inputs in the input paths of the property gate and whether these primary inputs are unate or binate. To do so, in one embodiment, the computing system sets the output of the property gate in an error state and then traverses the input paths of the property gate to identify the values of the logic in the inputs paths that would result in the property gate being in the error state. Based on these polarities, the system can identify the unate and binate primary inputs.Type: ApplicationFiled: May 3, 2016Publication date: November 9, 2017Inventors: Jason R. BAUMGARTNER, Raj K. Gajavelly, Alexander Ivrii, Pradeep K. Nalla
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Publication number: 20170323043Abstract: Embodiments herein describe a verification process that identifies unate primary inputs in input paths of a property gate. A property gate is logic inserted in a hardware design represented by a netlist which is used to verify the design. Before performing the verification process, a computing system evaluates the netlist to identify the primary inputs in the input paths of the property gate and whether these primary inputs are unate or binate. To do so, in one embodiment, the computing system sets the output of the property gate in an error state and then traverses the input paths of the property gate to identify the values of the logic in the inputs paths that would result in the property gate being in the error state. Based on these polarities, the system can identify the unate and binate primary inputs.Type: ApplicationFiled: May 3, 2016Publication date: November 9, 2017Inventors: Jason R. BAUMGARTNER, Raj K. Gajavelly, Alexander Ivrii, Pradeep K. Nalla
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Patent number: 9715564Abstract: A method for performing redundancy identification in an integrated circuit design. An optimized gate in a logic circuit is identified. A first netlist with a representation of the logic circuit is generated. An error is induced on the optimized gate. A second netlist is generated from a copy of the first netlist incorporating changes based on the error. Fan-out boundaries of the logic circuit are propagated for the first and second netlists. A redundancy report representing optimization steps performed to obtain the original logic circuit is analyzed to identify which steps are adequate to cause unobservability of the optimized gate. This is done by representing the optimization steps as constraints over the first and second netlists. Responsive to the error becoming undetectable under the constraints derived from the redundancy report, a minimal set of reductions is identified from the first netlist as the reason for unobservability of the optimized gate.Type: GrantFiled: October 28, 2015Date of Patent: July 25, 2017Assignee: International Business Machines CorporationInventors: Jason R. Baumgartner, Raj K. Gajavelly, Ashutosh Misra, Pradeep K. Nalla
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Publication number: 20170124240Abstract: A method for performing redundancy identification in an integrated circuit design. An optimized gate in a logic circuit is identified. A first netlist with a representation of the logic circuit is generated. An error is induced on the optimized gate. A second netlist is generated from a copy of the first netlist incorporating changes based on the error. Fan-out boundaries of the logic circuit are propagated for the first and second netlists. A redundancy report representing optimization steps performed to obtain the original logic circuit is analyzed to identify which steps are adequate to cause unobservability of the optimized gate. This is done by representing the optimization steps as constraints over the first and second netlists. Responsive to the error becoming undetectable under the constraints derived from the redundancy report, a minimal set of reductions is identified from the first netlist as the reason for unobservability of the optimized gate.Type: ApplicationFiled: October 28, 2015Publication date: May 4, 2017Inventors: Jason R. Baumgartner, Raj K. Gajavelly, Ashutosh Misra, Pradeep K. Nalla
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Patent number: 9483595Abstract: Liveness verification of a logic design is performed using various shadow abstraction refinement techniques. An initial subset of state elements are included in the shadow abstraction, and verification is performed (liveness-to-safety conversion) using this initial subset. If a liveness counterexample is detected, the shadow abstraction is refined by designating a second subset of the state elements different from the initial subset for inclusion in a refined abstraction. The initial subset can be designated by choosing all registers in a combinational fan-in of a liveness property of the design. High-performance algorithms for abstract liveness-to-safety conversion can be based upon simulation and counterexample refinement, bounded model checking and counterexample refinement, bounded model checking and proof-based refinement, proofs obtained during bounded model checking of a precise liveness checking problem, a hybrid of counterexample-based refinement and proof analysis, and proofs obtained.Type: GrantFiled: June 3, 2015Date of Patent: November 1, 2016Assignee: International Business Machines CorporationInventors: Jason R. Baumgartner, Raj K. Gajavelly, Robert L. Kanzelman, Hari Mony, Pradeep K. Nalla
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Patent number: 9471734Abstract: Liveness verification of a logic design is performed using various shadow abstraction refinement techniques. An initial subset of state elements are included in the shadow abstraction, and verification is performed (liveness-to-safety conversion) using this initial subset. If a liveness counterexample is detected, the shadow abstraction is refined by designating a second subset of the state elements different from the initial subset for inclusion in a refined abstraction. The initial subset can be designated by choosing all registers in a combinational fan-in of a liveness property of the design. High-performance algorithms for abstract liveness-to-safety conversion can be based upon simulation and counterexample refinement, bounded model checking and counterexample refinement, bounded model checking and proof-based refinement, proofs obtained during bounded model checking of a precise liveness checking problem, a hybrid of counterexample-based refinement and proof analysis, and proofs obtained.Type: GrantFiled: January 19, 2015Date of Patent: October 18, 2016Assignee: International Business Machines CorporationInventors: Jason R. Baumgartner, Raj K. Gajavelly, Robert L. Kanzelman, Hari Mony, Pradeep K. Nalla
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Publication number: 20160210388Abstract: Liveness verification of a logic design is performed using various shadow abstraction refinement techniques. An initial subset of state elements are included in the shadow abstraction, and verification is performed (liveness-to-safety conversion) using this initial subset. If a liveness counterexample is detected, the shadow abstraction is refined by designating a second subset of the state elements different from the initial subset for inclusion in a refined abstraction. The initial subset can be designated by choosing all registers in a combinational fan-in of a liveness property of the design. High-performance algorithms for abstract liveness-to-safety conversion can be based upon simulation and counterexample refinement, bounded model checking and counterexample refinement, bounded model checking and proof-based refinement, proofs obtained during bounded model checking of a precise liveness checking problem, a hybrid of counterexample-based refinement and proof analysis, and proofs obtained.Type: ApplicationFiled: January 19, 2015Publication date: July 21, 2016Inventors: Jason R. Baumgartner, Raj K. Gajavelly, Robert L. Kanzelman, Hari Mony, Pradeep K. Nalla
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Publication number: 20160210389Abstract: Liveness verification of a logic design is performed using various shadow abstraction refinement techniques. An initial subset of state elements are included in the shadow abstraction, and verification is performed (liveness-to-safety conversion) using this initial subset. If a liveness counterexample is detected, the shadow abstraction is refined by designating a second subset of the state elements different from the initial subset for inclusion in a refined abstraction. The initial subset can be designated by choosing all registers in a combinational fan-in of a liveness property of the design. High-performance algorithms for abstract liveness-to-safety conversion can be based upon simulation and counterexample refinement, bounded model checking and counterexample refinement, bounded model checking and proof-based refinement, proofs obtained during bounded model checking of a precise liveness checking problem, a hybrid of counterexample-based refinement and proof analysis, and proofs obtained.Type: ApplicationFiled: June 3, 2015Publication date: July 21, 2016Inventors: Jason R. Baumgartner, Raj K. Gajavelly, Robert L. Kanzelman, Hari Mony, Pradeep K. Nalla