Patents by Inventor Eric A. Foreman
Eric A. Foreman 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: 8413095Abstract: A statistical single library that includes on-chip variation (OCV) is created for timing and power analysis of a digital chip design. Initially, library values for all cells of a digital chip design, including ranges for environmental and process parameters, are subject to a statistical model to create statistical timing for the ranges of the parameters. A statistical timing tool is applied across the ranges of the parameters to determine statistical corners for delay and input power to a subset of cells. The statistically determined delay and input power to the subset of cells is entered into the statistical single library. Each delay of each statistical corner for the subset of cells is compared with a chip sign-off statistical delay requirement of a test macro.Type: GrantFiled: February 21, 2012Date of Patent: April 2, 2013Assignee: International Business Machines CorporationInventors: John P. Dubuque, Eric A. Foreman, Peter A. Habitz, Jeffrey G. Hemmett, Amol A. Joshi, Christopher J. Kiegle, William J. Wright, Vladimir Zolotov
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Publication number: 20130036395Abstract: Aspects of the present invention provide solutions for projecting slack in an integrated circuit. A statistical static timing analysis (SSTA) is computed to get a set of Gaussian distributions over a plurality of variation sources in the integrated circuit. Based on the Gaussian distributions, a truncated subset and a remainder subset of the Gaussian distributions are identified. Then data factors that represent a ratio between the remainder subset and the truncated subset are obtained. These data factors are applied to the SSTA to root sum square (RSS) project the slack for the integrated circuit that takes into account the absence of the truncated subset.Type: ApplicationFiled: August 3, 2011Publication date: February 7, 2013Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Eric A. Foreman, James C. Gregerson, Peter A. Habitz, Jeffrey G. Hemmett, Debjit Sinha, Natesan Venkateswaran, Chandramouli Visweswariah, Xiaoyue Wang, Vladmimir Zolotov
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Publication number: 20130031523Abstract: Systems and methods for accommodating correlated parameters in SSTA are provided. The method includes determining a correlation between at least two parameters. The method further includes calculating a new parameter or a new parameter set based on the correlation between the at least two parameters. The method further includes performing the SSTA such that the new parameter or the new parameter set is propagated into the SSTA. The method further includes projecting slack using the correlation between the at least two parameters and using a processor.Type: ApplicationFiled: July 25, 2011Publication date: January 31, 2013Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Eric A. FOREMAN, Peter A. HABITZ, David J. HATHAWAY, Jeffrey G. Hemmett, Natesan VENKATESWARAN, Chandramouli VISWESWARIAH, Vladimir ZOLOTOV
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Publication number: 20130018617Abstract: Solutions for integrating manufacturing feedback into an integrated circuit design are disclosed. In one embodiment, a computer-implemented method is disclosed including: defining an acceptable yield requirement for a first integrated circuit product; obtaining manufacturing data about the first integrated circuit product; performing a regression analysis on data representing paths in the first integrated circuit product to define a plurality of parameter settings based upon the acceptable yield requirement and the manufacturing data; determining a projection corner associated with the parameter settings for satisfying the acceptable yield requirement; and modifying a design of a second integrated circuit product based upon the projection corner and the plurality of parameter settings.Type: ApplicationFiled: July 13, 2011Publication date: January 17, 2013Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Nathan C. Buck, Brian M. Dreibelbis, John P. Dubuque, Eric A. Foreman, Peter A. Habitz, Jeffrey G. Hemmett, Natesan Venkateswaran, Chandramouli Visweswariah, Xiaoyue Wang, Vladmimir Zolotov
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Publication number: 20120084066Abstract: A computer-implemented method that simulates NPskew effects on a combination NFET (Negative Field Effect Transistor)/PFET (Positive Field Effect Transistor) semiconductor device using slew perturbations includes performing a timing test by a computing device, by: (1) evaluating perturb slews in Strong N/Weak P directions on the combination semiconductor device for a timing test result; (2) evaluation perturb slews in Weak N/Strong P directions on the combination semiconductor device for a timing test result; and (3) evaluating unperturbed slews in a balanced condition on the combination semiconductor device for a timing test result. After each test is performed, a determination is made as to which evaluation of the perturbed and unperturbed slews produces a most conservative timing test result for the combination semiconductor device. An NPskew effect adjusted timing test result is finally output based on determining the most conservative timing test result.Type: ApplicationFiled: September 30, 2010Publication date: April 5, 2012Applicant: International Business Machines CorporationInventors: Nathan C. Buck, Brian M. Dreibelbis, John P. Dubuque, Eric A. Foreman, Peter A. Habitz, Jeffrey G. Hemmett, Natesan Venkateswaran, Chandramouli Visweswariah, Xiaoyue X. Wang
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Patent number: 8141014Abstract: A system and method for adjustment of modeled timing data variation as a function of past state and/or switching history during static timing analysis. One illustrative embodiment may include inputting and asserting at least one of initial signal history bound and explicit device history bound constraints for at least one signal of a circuit design and evaluating for a segment processed during a forward propagation of block based static timing analysis whether any input signal to a current segment has a bounded history, at least one of propagated and asserted. The method may further include evaluating for the segment whether history bounds are downstream from a gating restriction, and processing a next segment until there are no further segments.Type: GrantFiled: August 10, 2009Date of Patent: March 20, 2012Assignee: International Business Machines CorporationInventors: Eric A. Foreman, Peter A. Habitz, David J. Hathaway, Jeffrey G. Hemmett, Kerim Kalafala, Jeffrey P. Soreff
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Patent number: 8141025Abstract: A method for verifying whether a circuit meets timing constraints by performing an incremental static timing analysis in which slack is represented by a distribution that includes sensitivities to various process variables. The slack at an endpoint is computed by propagating the arrival times and required arrival times of paths leading up to the endpoint. The computation of arrival and required arrival times needs the computation of delays of individual gate and wire segments in each path that leads to the endpoint. The mixed mode adds a deterministic timing to the statistical timing (DSTA+SSTA).Type: GrantFiled: January 15, 2009Date of Patent: March 20, 2012Assignee: International Business Machines CorporationInventors: Debjit Sinha, Eric A. Foreman, Peter A. Habitz, Natesan Venkateswaran, Chandramouli Visweswariah, Vladimir Zolotov
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Patent number: 8141012Abstract: An approach for covering multiple selective timing corners in a single statistical timing run is described. In one embodiment, a single statistical timing analysis is run on the full parameter space that covers unlimited process parameters/environment conditions. Results from the statistical timing analysis are projected for selected corners. Timing closure is performed on the corners having the worst slacks.Type: GrantFiled: August 27, 2009Date of Patent: March 20, 2012Assignee: International Business Machines CorporationInventors: Nathan C. Buck, Brian M. Dreibelbis, John P. Dubuque, Eric A. Foreman, Peter A. Habitz, Jeffrey G. Hemmett, Susan K. Lichtensteiger, Natesan Venkateswaran, Chandramouli Visweswariah, Xiaoyue Wang
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Patent number: 8108816Abstract: A system and method for the adjustment of history based delay variation during static timing analysis of an integrated circuit design. The method may include obtaining information through sources of variability of history based components of delay variability, and a relationship between the sources of variability and one or more bounded device histories. Then, inputting history bounds for at least one signal of the integrated circuit design, and computing and propagating history bounds through at least one first segment of the integrated circuit design to at least one signal of the integrated circuit design. Further, the method may include evaluating from at least one of the propagated history bounds, device history bounds for at least one second segment of the integrated circuit design, and based on the evaluated device history bounds, adjusting at least one of a value of the history based delay variability and propagation of timing.Type: GrantFiled: June 15, 2009Date of Patent: January 31, 2012Assignee: International Business Machines CorporationInventors: Eric A. Foreman, Peter A. Habitz, David J. Hathaway, Jeffrey G. Hemmett, Kerim Kalafala, Jeffrey P. Soreff
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Patent number: 8086988Abstract: Disclosed is a computer-implemented method for designing a chip to optimize yielding parts in different bins as a function of multiple diverse metrics and further to maximize the profit potential of the resulting chip bins. The method separately calculates joint probability distributions (JPD), each JPD being a function of a different metric (e.g., performance, power consumption, etc.). Based on the JPDs, corresponding yield curves are generated. A profit function then reduces the values of all of these metrics (e.g., performance values, power consumption values, etc.) to a common profit denominator (e.g., to monetary values indicating profit that may be associated with a given metric value). The profit function and, more particularly, the monetary values can be used to combine the various yield curves into a combined profit-based yield curve from which a profit model can be generated.Type: GrantFiled: May 18, 2009Date of Patent: December 27, 2011Assignee: International Business Machines CorporationInventors: Nathan Buck, Howard H. Chen, James P. Eckhardt, Eric A. Foreman, James C. Gregerson, Peter A. Habitz, Susan K. Lichtensteiger, Chandramouli Visweswariah, Tad J. Wilder
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Patent number: 8056035Abstract: A method of performing statistical timing analysis of a logic design, including effects of signal coupling, includes performing a deterministic analysis to determine deterministic coupling information for at least one aggressor/victim net pair of the logic design. Additionally, the method includes performing a statistical timing analysis in which the deterministic coupling information for the at least one aggressor/victim net pair is combined with statistical values of the statistical timing analysis to determine a statistical effective capacitance of a victim of the aggressor/victim net pair. Furthermore, the method includes using the statistical effective capacitance to determine timing data used in the statistical timing analysis.Type: GrantFiled: June 4, 2008Date of Patent: November 8, 2011Assignee: International Business Machines CorporationInventors: Nathan C. Buck, Brian M. Dreibelbis, John P. Dubuque, Eric A. Foreman, Peter A. Habitz, David J. Hathaway, Gregory M. Schaeffer, Chandramouli Visweswariah
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Publication number: 20110140745Abstract: A method performs statistical static timing analysis of a network that includes a phase-locked loop and a feedback path. The feedback path comprises a set of delays operatively connected from the output of the phase-locked loop back to the input of the phase-locked loop. One embodiment herein computes a statistical feedback path delay for the feedback path. The method can use a separate statistical parameter to represent random uncorrelated delay variation for each delay in the feedback path. The method also computes an output arrival time for the phase-locked loop based on the negative of the statistical feedback path delay.Type: ApplicationFiled: December 15, 2009Publication date: June 16, 2011Applicant: International Business Machines CorporatinoInventors: Nathan C. Buck, Brian M. Dreibelbis, John P. Dubuque, Eric A. Foreman, Peter A. Habitz
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Patent number: 7962874Abstract: Methods for analyzing the timing in integrated circuits and for reducing the pessimism in timing slack calculations in static timing analysis (STA). The methods involve grouping and canceling the delay contributions of elements having similar delays in early and late circuit paths. An adjusted timing slack is calculated using the delay contributions of elements having dissimilar delays. In some embodiments, the delay contributions of elements having dissimilar delays are root sum squared. Embodiments of the invention provide methods for reducing the pessimism due to both cell-based and wire-dependent delays. The delays considered in embodiments of the invention may include delays due to the location of elements in a path.Type: GrantFiled: July 31, 2008Date of Patent: June 14, 2011Assignee: International Business Machines CorporationInventors: Eric A. Foreman, Peter A. Habitz, David J. Hathaway, Jerry D. Hayes, Anthony D. Polson
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Publication number: 20110126163Abstract: A method receives an initial circuit design. The circuit design includes at least one path having at least one beginning point comprising a source, at least one ending point comprising a sink, and one or more circuit elements between the source and the sink. The method evaluates timing performance parameter sensitivities to manufacturing variations of each of the elements to identify how much each element will increase or decrease the timing performance parameter of the path for each change in each manufacturing variable associated with manufacturing the elements. Further, the method alters the elements within the path until elements that produce positive changes to the timing performance parameter for a given manufacturing variable change approximately equals (in magnitude) elements that produce negative changes to the timing performance parameter for the given manufacturing variable change, to produce an altered circuit design.Type: ApplicationFiled: November 24, 2009Publication date: May 26, 2011Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Peter A. Habitz, Eric A. Foreman, Gustavo E. Tellez
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Publication number: 20110055793Abstract: An approach for covering multiple selective timing corners in a single statistical timing run is described. In one embodiment, a single statistical timing analysis is run on the full parameter space that covers unlimited process parameters/environment conditions. Results from the statistical timing analysis are projected for selected corners. Timing closure is performed on the corners having the worst slacks.Type: ApplicationFiled: August 27, 2009Publication date: March 3, 2011Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Nathan C. Buck, Brian M. Dreibelbis, John P. Dubuque, Eric A. Foreman, Peter A. Habitz, Jeffrey G. Hemmett, Susan K. Lichtensteiger, Natesan Venkateswaran, Chandramouli Visweswariah, Xiaoyue Wang
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Publication number: 20110035714Abstract: A system and method for adjustment of modeled timing data variation as a function of past state and/or switching history during static timing analysis. One illustrative embodiment may include inputting and asserting at least one of initial signal history bound and explicit device history bound constraints for at least one signal of a circuit design and evaluating for a segment processed during a forward propagation of block based static timing analysis whether any input signal to a current segment has a bounded history, at least one of propagated and asserted. The method may further include evaluating for the segment whether history bounds are downstream from a gating restriction, and processing a next segment until there are no further segments.Type: ApplicationFiled: August 10, 2009Publication date: February 10, 2011Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Eric A. Foreman, Peter A. Habitz, David J. Hathaway, Jeffrey G. Hemmett, Kerim Kalafala, Jeffrey P. Soreff
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Patent number: 7886246Abstract: Methods for identifying failing timing requirements in a digital design. The method includes identifying at least one timing test in the digital design that has a passing slack in a base process corner and a failing slack in a different process corner. The method further includes computing a sensitivity of the failing slack to each of a plurality of variables and comparing each sensitivity to a respective sensitivity threshold. If the sensitivity of at least one of the variables is greater than the respective sensitivity threshold, then the at least one timing test is considered to fail.Type: GrantFiled: April 16, 2008Date of Patent: February 8, 2011Assignee: International Business Machines CorporationInventors: Nathan C. Buck, John P. Dubuque, Eric A. Foreman, Peter A. Habitz, Chandramouli Visweswariah
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Patent number: 7873926Abstract: Methods for analyzing timing of an integrated circuit using block-based static statistical timing analysis and for practical worst test definition and debug. The method includes building a timing graph, determining a slack for each of the nodes in the timing graph, and identifying a statistically worst slack for at least one of the nodes. The method further includes replacing this statistically worst slack with a proxy worst slack.Type: GrantFiled: March 31, 2008Date of Patent: January 18, 2011Assignee: International Business Machines CorporationInventors: Nathan C. Buck, Eric A. Foreman, James C. Gregerson, Jeffrey G. Hemmett
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Patent number: 7870525Abstract: A method, system and program product are disclosed for improving an IC design that prioritize failure coefficients of slacks that lead to correction according to their probability of failure. With an identified set of independent parameters, a sensitivity analysis is performed on each parameter by noting the difference in timing, typically on endpoint slacks, when the parameter is varied. This step is repeated for every independent parameter. A failure coefficient is then calculated from the reference slack and the sensitivity of slack for each of the timing endpoints and a determination is made as to whether at least one timing endpoint fails a threshold test. Failing timing endpoints are then prioritized for modification according to their failure coefficients. The total number of runs required is one run that is used as a reference run, plus one additional run for each parameter.Type: GrantFiled: May 16, 2008Date of Patent: January 11, 2011Assignee: International Business Machines CorporationInventors: Eric A. Foreman, Peter A. Habitz, David J. Hathaway, Jerry D. Hayes, Jeffrey H. Oppold, Anthony D. Polson
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Publication number: 20100318951Abstract: A system and method for the adjustment of history based delay variation during static timing analysis of an integrated circuit design. The method may include obtaining information through sources of variability of history based components of delay variability, and a relationship between the sources of variability and one or more bounded device histories. Then, inputting history bounds for at least one signal of the integrated circuit design, and computing and propagating history bounds through at least one first segment of the integrated circuit design to at least one signal of the integrated circuit design. Further, the method may include evaluating from at least one of the propagated history bounds, device history bounds for at least one second segment of the integrated circuit design, and based on the evaluated device history bounds, adjusting at least one of a value of the history based delay variability and propagation of timing.Type: ApplicationFiled: June 15, 2009Publication date: December 16, 2010Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Eric A. Foreman, Peter A. Habitz, David J. Hathaway, Jeffrey G. Hemmett, Kerim Kalafala, Jeffrey P. Soreff