Patents by Inventor Igor Keller

Igor Keller 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).

  • Publication number: 20240143877
    Abstract: Disclosed is an improved approach to implement sharing of delay calculations for replicated portions of a design, where input slews may be different between those replicated design portions. This allows the system to experience runtime improvements for timing analysis of electronic designs.
    Type: Application
    Filed: October 31, 2022
    Publication date: May 2, 2024
    Applicant: Cadence Design Systems, Inc.
    Inventors: Igor Keller, Nikita Sergeev, Pradeep Yadav, Maksim Baranov
  • Patent number: 11775719
    Abstract: Various embodiments provide a charge model for a cell instance for delay calculation of a circuit design that includes the cell instance, where the charge model can be part of electronic design automation (EDA) and used in timing analysis of a circuit design that includes the cell instance. The charge model generated by an embodiment can predict a charge at an input of a cell instance for an arbitrary input voltage waveform and can address (e.g., reduce or negate) a time delay impact the Miller effect has on the cell instance.
    Type: Grant
    Filed: April 4, 2022
    Date of Patent: October 3, 2023
    Assignee: Cadence Design Systems, Inc.
    Inventors: Igor Keller, Xiaopeng Dong, Sourabh Rajguru
  • Patent number: 11188696
    Abstract: An approach is described for a method, system, and product for deferred merge based method for graph based analysis to reduce pessimism. According to some embodiments, the approach includes receiving design data, static and/or statistical timing analysis data, identifying cells and interconnects for performing graph based worst case timing analysis where merger of signals is deferred based on one or more conditions to reduce pessimism, and generating results thereof. Other additional objects, features, and advantages of the invention are described in the detailed description, figures, and claims.
    Type: Grant
    Filed: April 15, 2019
    Date of Patent: November 30, 2021
    Assignee: Cadence Design Systems, Inc.
    Inventors: Amit Dhuria, Sri Harsha Venkata Pothukuchi, Pradeep Yadav, Pawan Kulshreshtha, Igor Keller, Sharad Mehrotra, Jean Pierre Hiol, Krishna Prasad Belkhale
  • Patent number: 11023636
    Abstract: Disclosed are methods, systems, and articles of manufacture for characterizing an electronic design with a susceptibility window. These techniques identify a set of multiple aggressors in an electronic design and determine, at a susceptibility window module stored in memory and executing in conjunction with a microprocessor of a computing node, a susceptibility window for an internal node of a victim and a timing window for the set of multiple aggressors in the electronic design. These techniques further determine a subset having at least one aggressor using at least the susceptibility window of the victim and the timing window for the set of multiple aggressors, and determine whether a glitch in the electronic design causes a violation at the internal node of the electronic design based at least in part upon the timing window and the susceptibility.
    Type: Grant
    Filed: May 13, 2020
    Date of Patent: June 1, 2021
    Assignee: Cadence Design Systems, Inc.
    Inventors: Igor Keller, Ratnakar Goyal, Manuj Verma, Harmandeep Singh
  • Patent number: 11023640
    Abstract: Disclosed are methods, systems, and articles of manufacture for characterizing timing behavior of an electronic design with a derived current waveform. A set of inputs is determined from a set of electrical characteristics of an electronic design or a portion thereof. Moreover, A derived current waveform is determined at one or more modules stored in memory and executing in conjunction with a microprocessor of a computing node based at least in part upon the set of inputs. The electronic design or the portion thereof is characterized based at least in part upon the derived current waveform.
    Type: Grant
    Filed: May 13, 2020
    Date of Patent: June 1, 2021
    Assignee: Cadence Design Systems, Inc.
    Inventors: Igor Keller, Chirayu S. Amin, Omid Assare
  • Patent number: 10963610
    Abstract: The present embodiments are generally directed to analyzing clock jitter. Jitter affects the clock delay of the circuit and the time the clock is available at sync points, so it is important to calculate its impact correctly to take appropriate margin during timing analysis. Jitter could be due to various reasons—one of them is due to IR Impact on the Clock Tree. IR drop variations between the two consecutive cycles can effectively reduce the available clock period for data to be correctly captured.
    Type: Grant
    Filed: May 22, 2020
    Date of Patent: March 30, 2021
    Assignee: Cadence Design Systems, Inc.
    Inventors: Igor Keller, Vishnu Kumar
  • Patent number: 10789406
    Abstract: The present embodiments are generally directed to electronic circuit design and verification and more particularly to techniques for characterizing electronic components within an electronic circuit design for use in verification. In one or more embodiments, an adaptive sensitivity based analysis is used to build an adaptive equation to represent the timing response surface for an electronic component. With the adaptive surface response built, a sample-based evaluation yields highly accurate extraction of electronic component timing parameters including on-chip variation information such as sigma and moments.
    Type: Grant
    Filed: November 16, 2018
    Date of Patent: September 29, 2020
    Assignee: Cadence Design Systems, Inc.
    Inventors: Shiva Raja, Igor Keller, Ling Wang
  • Patent number: 10430536
    Abstract: An approach is described for yield calculation using statistical timing data that accounts for path and stage delay correlation. Embodiments of the present invention provide an improved approach for yield calculation using statistical timing data that accounts for path and stage delay correlation. According to some embodiments, the approach includes receiving statistical timing analysis data, identifying paths for performing timing analysis, performing timing analysis where common segments of different paths are analyzed using shared data and where subsequent stages are transformed to provide an expected correlation between stages, and generating yield probability results based on at least the results of calculating timing analysis.
    Type: Grant
    Filed: September 29, 2017
    Date of Patent: October 1, 2019
    Assignee: Cadence Design Systems, Inc.
    Inventors: Igor Keller, Praveen Ghanta, Mikhail Chetin
  • Patent number: 10275554
    Abstract: A method as provided includes retrieving a correlation value from a correlation table and a coskewness value from a coskewness table. The correlation value includes a correlation between a delay distribution and a slew rate distribution, and is associated with both: an input slew rate and an output load, in a logic stage in an integrated circuit design, and the coskewness value is a coskewness between the delay distribution and the slew rate distribution. The method includes determining a partial derivative of a delay function relative to the input slew rate, determining a delay distribution for a signal through a plurality of logic stages using the correlation value, the coskewness value, and the partial derivative of the delay function relative to the input slew rate. The method also includes verifying that a statistical value of the delay distribution satisfies a desired performance value for an integrated circuit.
    Type: Grant
    Filed: July 17, 2017
    Date of Patent: April 30, 2019
    Assignee: CADENCE DESIGN SYSTEMS, INC.
    Inventors: Mikhail Chetin, Igor Keller, Praveen Ghanta
  • Patent number: 10192012
    Abstract: A method for determining a signal electromigration effect in a circuit includes obtaining a partition netlist from a partition of an integrated circuit netlist and identifying a complementary netlist that couples a second input with the output is provided. The complementary netlist is logically independent from the reference netlist. The method includes modifying the partition netlist to couple the reference netlist and the complementary netlist in an inverting configuration, and providing an electromagnetic pulse to at least one of the first input or the second input to induce a current through one of the plurality of circuit components. The method also includes determining an electromigration effect from the current on the one of the plurality of circuit components.
    Type: Grant
    Filed: March 27, 2017
    Date of Patent: January 29, 2019
    Inventors: Jalal Wehbeh, Aswin Ramakrishnan, Igor Keller, Federico Politi, Ajish Thomas
  • Patent number: 10185795
    Abstract: Electronic design automation systems, methods, and media are presented for characterizing on-chip variation of circuit elements in a circuit design using statistical values including skew, and for performing statistical static timing analysis using these statistical values. One embodiment models delay characteristics under certain operating conditions for circuit elements with asymmetric (e.g., non-Gaussian) probability density functions using normalized skewness. The modeled delay can then be used to perform various timing analysis operations.
    Type: Grant
    Filed: October 11, 2016
    Date of Patent: January 22, 2019
    Assignee: Cadence Design Systems, Inc.
    Inventors: Igor Keller, Praveen Ghanta, Arun Kumar Mishra
  • Patent number: 10073934
    Abstract: Electronic design automation systems, methods, and media are presented for characterizing on-chip variation of circuit elements in a circuit design using statistical values including skew, and for performing statistical static timing analysis using these statistical values. One embodiment models delay characteristics under certain operating conditions for circuit elements with asymmetric (e.g., non-Gaussian) probability density functions using normalized skewness. This information is then accessed in other embodiments, and scaled to generate scaled timing values describing the statistical timing characteristics of a circuit element or block estimated from the skew-based values. These values may then be used for further timing analysis.
    Type: Grant
    Filed: October 11, 2016
    Date of Patent: September 11, 2018
    Assignee: Cadence Design Systems, Inc.
    Inventors: Igor Keller, Praveen Ghanta, Arun Kumar Mishra
  • Patent number: 9928324
    Abstract: A system, method, and computer program product for modeling a receiver load in static timing analysis of digital circuits. Embodiments separate total receiver charge into static and dynamic components, and extract both from an improved library model. The receiver load is effectively modeled with a static capacitance and a current source connected in parallel. A method of extracting load model characteristics from a standard timing library is also provided. The improved receiver model reflects the physical phenomena not currently modeled, and enables a more accurate description of circuit behavior while still using a simple approximation of the transistor level circuit. The complete circuit switching response is found through a perturbative approach, combining a linear response using constant capacitance values with a correction having time-dependent charges for modeling physical phenomena such as the back-Miller effect.
    Type: Grant
    Filed: April 29, 2014
    Date of Patent: March 27, 2018
    Assignee: CADENCE DESIGN SYSTEMS, INC.
    Inventors: Igor Keller, William Franson Scott
  • Patent number: 9881123
    Abstract: A method and system are provided for timing analysis of an electronic circuit design. A timing graph defines a plurality of timing paths through different subsections of the electronic circuit design. A timing window is defined for each of the nodes included in a timing path. At least one preliminary round of a predetermined signal integrity analysis is executed on the circuit design based on the timing windows to identify at least one pair of crosstalk-coupled victim and aggressor nodes. Each victim node's timing window is adaptively adjusted according to a predetermined timing property thereof. At least one primary round of the predetermined signal integrity analysis is executed on the electronic circuit design based in part on this adaptively adjusted timing window for each victim node to generate a delay, which is annotated to the timing graph. A predetermined static timing analysis is executed based on the delay-annotated timing graph.
    Type: Grant
    Filed: June 30, 2016
    Date of Patent: January 30, 2018
    Assignee: Cadence Design Systems, Inc.
    Inventors: Ratnakar Goyal, Manuj Verma, Igor Keller, Arvind Nembili Veeravalli
  • Patent number: 9710593
    Abstract: Disclosed are techniques for enhancing timing analyses with reduced timing libraries for electronic designs. These techniques determine dominance relations for multiple timing models for timing analyses and generate a dominance adjacency data structure based at least in part upon the dominance relations. The dominance adjacency data structure may be stored at a first location of a non-transitory computer accessible storage medium. The plurality of timing models may be reduced into a reduced set of timing models at least by providing the dominance adjacency data structure as an input to a transformation and further by transforming the dominance adjacency data structure with the transformation into the reduced set of timing models that are used in timing analyses for an electronic design or a portion thereof.
    Type: Grant
    Filed: October 14, 2015
    Date of Patent: July 18, 2017
    Assignee: Cadence Design Systems, Inc.
    Inventors: Igor Keller, Mikhail Chetin, Xiaojun Sun
  • Patent number: 9582626
    Abstract: Accurate timing analysis during STA is performed using detailed waveform information in addition to the traditional slew information. A waveform memory system efficiently stores the detailed waveforms that are used in, calculated during, and propagated throughout timing analysis for a circuit design. During the STA process, for multiple modeled stages of circuit design, a waveform including information detailing the form of the waveform is compressed, stored in, decompressed, and retrieved from a memory system. The memory system provides for storage efficiencies including long-term and short-term storage areas, multi-level storage, and separate storage for each view evaluated during the STA.
    Type: Grant
    Filed: November 20, 2014
    Date of Patent: February 28, 2017
    Assignee: Cadence Design Systems, Inc.
    Inventors: Igor Keller, Eddy Pramono, Jijun Chen, Nikolay Rubanov
  • Patent number: 9384310
    Abstract: A system and method for performing multi-mode multi-corner (MMMC) analysis such that multiple views or conditions can be analyzed together to improve runtime by taking advantage of common steps of analysis in different corners. Views are clustered based on their similarity to one another to take advantage of calculations and other tasks that may be shared between views during timing analysis. Then, during timing analysis, each net in the design is analyzed for each view.
    Type: Grant
    Filed: September 30, 2014
    Date of Patent: July 5, 2016
    Assignee: CADENCE DESIGN SYSTEMS, INC.
    Inventors: Igor Keller, Jijun Chen, Pradeep Yadav
  • Patent number: 9129078
    Abstract: Systems, apparatus, and methods of static timing analysis for an integrated circuit design in the presence of noise are disclosed. The integrated circuit design may be partitioned into a plurality of circuit stages. A timing graph including timing arcs is constructed to represent the timing delays in circuit stages of the integrated circuit design. A model of each circuit stage may be formed including a model of a victim driver, an aggressor driver, a victim receiver, and a victim net and an aggressor net coupled together. For each timing arc in the timing graph, full timing delays may be computed for the timing arcs in each circuit stage.
    Type: Grant
    Filed: October 30, 2013
    Date of Patent: September 8, 2015
    Assignee: Cadence Design Systems, Inc.
    Inventors: Igor Keller, Vinod Kariat, King Ho Tam
  • Patent number: 9003342
    Abstract: A lumped aggressor model is used to simulate multiple aggressor nets acting on a victim net. By lumping the aggressor nets together into a single input port, a single voltage excitation may be applied to the input port to simulate the model during static timing analysis. However, a record of each individual aggressor net and several associated attributes for each aggressor net is maintained such that the individual lumped aggressor nets may still be modeled as separate contributions to the attack on the victim net.
    Type: Grant
    Filed: March 31, 2014
    Date of Patent: April 7, 2015
    Assignee: Cadence Design Systems, Inc.
    Inventors: Igor Keller, Jijun Chen, Dhananjay Griyage
  • Patent number: 8966421
    Abstract: In one embodiment of the invention, a multi-CCC current source model is disclosed to perform statistical timing analysis of an integrated circuit design. The multi-CCC current source model includes a voltage waveform transfer function, a voltage dependent current source, and an output capacitor. The voltage waveform transfer function receives an input voltage waveform and transforms it into an intermediate voltage waveform. The voltage dependent current source generates an output current in response to the intermediate voltage waveform. The output capacitor is coupled in parallel to the voltage dependent current source to generate an output voltage waveform for computation of a timing delay.
    Type: Grant
    Filed: September 10, 2013
    Date of Patent: February 24, 2015
    Assignee: Cadence Design Systems, Inc.
    Inventors: Vinod Kariat, Igor Keller, Joel R. Phillips, King Ho Tam