Patents by Inventor Joel R. Phillips
Joel R. Phillips 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: 10860767Abstract: Various embodiments describe performing a transient simulation of circuits that have mutual inductors. In particular, some embodiments perform a transient simulation on a circuit model by removing and approximating the effects of one or more entries of a matrix in the circuit model, where the matrix relates to inductors or mutual inductors of the circuit. In doing so, such embodiments can render the matrix more sparse than before which, in turn, can reduce the time spent during the transient simulation to solve equations of the circuit model.Type: GrantFiled: January 2, 2018Date of Patent: December 8, 2020Assignee: Cadence Design Systems, Inc.Inventors: Mina Adel Aziz Farhan, Joel R. Phillips
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Static timing analysis methods for integrated circuit designs using a multi-CCC current source model
Patent number: 8966421Abstract: 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: GrantFiled: September 10, 2013Date of Patent: February 24, 2015Assignee: Cadence Design Systems, Inc.Inventors: Vinod Kariat, Igor Keller, Joel R. Phillips, King Ho Tam -
Patent number: 8782583Abstract: A system and method are disclosed for waveform based variational static timing analysis. A circuit is divided into its linear circuit parts and non-linear circuit parts and modeled together, by a combination of linear modeling techniques, into linear equations that may be represented by matrices. The linear equations in matrix form may be readily solved by a computer such that an input waveform to an input pin of the circuit can be sequentially “pushed” through the various interconnects and logic networks of the circuit to an output pin. Output voltage waveforms are obtained at each stage of the waveform pushing and may be used to perform static timing analysis.Type: GrantFiled: July 13, 2012Date of Patent: July 15, 2014Assignee: Cadence Design Systems, Inc.Inventors: Saurabh K Tiwary, Joel R. Phillips, Igor Keller
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Patent number: 8726211Abstract: A method is provided for use during static timing analysis of an integrated circuit design to produce an equivalent waveform model, the method comprising: using an analog model of the inner component, to simulate an inner component to produce multiple analog simulation output characterization waveforms as a function of multiple input waveforms used to characterize the design cell; using the analog model of the inner component to simulate the inner component to produce an analog simulation output waveform as a function of the complex waveform; and producing the equivalent waveform model as a function of the multiple analog simulation output characterization waveforms and the analog simulation output waveform.Type: GrantFiled: October 1, 2012Date of Patent: May 13, 2014Assignee: Cadence Design Systems, Inc.Inventors: Joel R. Phillips, Qunzeng Liu, Igor Keller
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Publication number: 20140096099Abstract: A method is provided for use during static timing analysis of an integrated circuit design to produce an equivalent waveform model, the method comprising: using an analog model of the inner component, to simulate an inner component to produce multiple analog simulation output characterization waveforms as a function of multiple input waveforms used to characterize the design cell; using the analog model of the inner component to simulate the inner component to produce an analog simulation output waveform as a function of the complex waveform; and producing the equivalent waveform model as a function of the multiple analog simulation output characterization waveforms and the analog simulation output waveform.Type: ApplicationFiled: October 1, 2012Publication date: April 3, 2014Applicant: Cadence Design Systems, Inc.Inventors: Joel R. Phillips, Qunzeng Liu, Igor Keller
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Patent number: 8631369Abstract: In one embodiment of the invention, a method of statically analyzing an integrated circuit with process and environment variations is provided. The method includes characterizing each circuit cell of a cell library for a sensitivity to process parameter variations within a predetermined range; creating a timing graph corresponding to a netlist representing an integrated circuit design; along nodes of the timing graph, computing delay values including sensitivities to process variations; for each selected output node of the netlist, propagating a full timing value function with the sensitivities to the selected output nodes; and generating a parameterized timing report including the sensitivities to the process variations.Type: GrantFiled: December 30, 2010Date of Patent: January 14, 2014Assignee: Cadence Design Systems, Inc.Inventors: Vinod Kariat, Joel R. Phillips, Igor Keller
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Patent number: 8601420Abstract: In one embodiment, a method of constructing an equivalent waveform model for static timing analysis of integrated circuit designs is disclosed. The method includes fitting time point coefficients (qk) and known time delay values from a delay and slew model of a receiving gate from a timing library; determining waveform values (Ikj) for input waveforms from the timing library; determining timing values (dj) from a timing table in the timing library in response to the input waveforms of the timing library; and determining coefficients (qk) by minimizing a residual of a delay equation.Type: GrantFiled: December 3, 2010Date of Patent: December 3, 2013Assignee: Cadence Design Systems, Inc.Inventors: Igor Keller, Joel R. Phillips, Jijun Chen
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Patent number: 8533644Abstract: 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: GrantFiled: December 12, 2010Date of Patent: September 10, 2013Assignee: Cadence Design Systems, Inc.Inventors: Vinod Kariat, Igor Keller, Joel R. Phillips, King Ho Tam
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Patent number: 8516420Abstract: 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: GrantFiled: August 31, 2007Date of Patent: August 20, 2013Assignee: Cadence Design Systems, Inc.Inventors: Vinod Kariat, Igor Keller, Joel R. Phillips, King Ho Tam
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Patent number: 8375343Abstract: A system and method are disclosed for waveform based variational static timing analysis. A circuit is divided into its linear circuit parts and non-linear circuit parts and modeled together, by a combination of linear modeling techniques, into linear equations that may be represented by matrices. The linear equations in matrix form may be readily solved by a computer such that an input waveform to an input pin of the circuit can be sequentially “pushed” through the various interconnects and logic networks of the circuit to an output pin. Output voltage waveforms are obtained at each stage of the waveform pushing and may be used to perform static timing analysis.Type: GrantFiled: December 9, 2008Date of Patent: February 12, 2013Assignee: Cadence Design Systems, Inc.Inventors: Saurabh K. Tiwary, Joel R. Phillips, Igor Keller
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Patent number: 8341572Abstract: A system and method are disclosed for waveform based variational static timing analysis. A circuit is divided into its linear circuit parts and non-linear circuit parts and modeled together, by a combination of linear modeling techniques, into linear equations that may be represented by matrices. The linear equations in matrix form may be readily solved by a computer such that an input waveform to an input pin of the circuit can be sequentially “pushed” through the various interconnects and logic networks of the circuit to an output pin. Output voltage waveforms are obtained at each stage of the waveform pushing and may be used to perform static timing analysis.Type: GrantFiled: December 9, 2008Date of Patent: December 25, 2012Assignee: Cadence Design Systems, Inc.Inventors: Saurabh K. Tiwary, Joel R. Phillips, Igor Keller
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Patent number: 8341567Abstract: A method is provided to formally verify a property of a circuit design comprising: receiving a description of at least a portion of the circuit; receiving an indication of search accuracy criteria; receiving a description of a relationship between current and voltage (I-V relationship) for one or more of devices of the circuit; converting each I-V relationship to a conservative approximation of such I-V relationship; assigning voltage labels to one or more terminals of one or more identified devices that indicate voltage relationships among the one or more terminals consistent with KVL; defining a respective current relationship among one or more respective sets of currents of the one or more of the identified devices that is consistent with KCL; searching for one or more combinations of current and voltage values that are within at least one region of each conservative approximation and that are consistent with the voltage labels and that are consistent with each respective defined current relationship; convType: GrantFiled: December 29, 2008Date of Patent: December 25, 2012Assignee: Cadence Design Systems, Inc.Inventors: Saurabh K. Tiwary, Anubhav Gupta, Joel R. Phillips, Claudio Pinello, Radu Zlatanovici
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Patent number: 8325188Abstract: Systems and methods for storing waveform data and outputting data to a waveform viewer are disclosed. A waveform is segmented into a plurality of segments, and data describing each segment is stored at several levels of resolution. When a user wishes to view a portion of the waveform, the appropriate segments of the waveform are identified, and the appropriate levels of resolution are selected. The data describing the appropriate segments at the appropriate levels of resolution are output to a waveform viewer. An index may be provided to aid in selection of the appropriate data. Various methods for compression of the data are also supported.Type: GrantFiled: July 21, 2006Date of Patent: December 4, 2012Assignee: Cadence Design Systems, Inc.Inventors: Joel R. Phillips, Sherry Solden, Henry C. Chang, Kenneth S. Kundert, Ted Vucurevich
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Patent number: 8245165Abstract: A system and method are disclosed for waveform based variational static timing analysis. A circuit is divided into its linear circuit parts and non-linear circuit parts and modeled together, by a combination of linear modeling techniques, into linear equations that may be represented by matrices. The linear equations in matrix form may be readily solved by a computer such that an input waveform to an input pin of the circuit can be sequentially “pushed” through the various interconnects and logic networks of the circuit to an output pin. Output voltage waveforms are obtained at each stage of the waveform pushing and may be used to perform static timing analysis.Type: GrantFiled: December 9, 2008Date of Patent: August 14, 2012Assignee: Cadence Design Systems, Inc.Inventors: Saurabh K. Tiwary, Joel R. Phillips, Igor Keller
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Patent number: 8195440Abstract: Described is a process for performing an improved mixed frequency-time algorithm to simulate responses of a circuit that receives a periodic sample signal and at least one information signal. The process selects a set of evenly spaced distinct time points and a set of reference time points. Each of the reference points is associated with a distinct time point, and a reference time point is a signal period away from its respective distinct time point. The process finds a first set of relationships between the values at the distinct time points and the values the reference time points. The process also finds a second set of relationships between the values at the distinct time points and the values at the reference time points. The process then combines the first and second sets of relationships to establish a system of nonlinear equations in terms of the values at the distinct time points only. By solving the system of nonlinear equations, the process finds simulated responses of the circuit in time domain.Type: GrantFiled: February 17, 2009Date of Patent: June 5, 2012Assignee: Cadence Design Systems, Inc.Inventors: Dan Feng, Joel R. Phillips, Kenneth Kundert
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Patent number: 7882471Abstract: In one embodiment of the invention, a method of statically analyzing an integrated circuit with process and environment variations is provided. The method includes characterizing each circuit cell of a cell library for a sensitivity to process parameter variations within a predetermined range; creating a timing graph corresponding to a netlist representing an integrated circuit design; along nodes of the timing graph, computing delay values including sensitivities to process variations; for each selected output node of the netlist, propagating a full timing value function with the sensitivities to the selected output nodes; and generating a parameterized timing report including the sensitivities to the process variations.Type: GrantFiled: November 15, 2006Date of Patent: February 1, 2011Assignee: Cadence Design Systems, Inc.Inventors: Vinod Kariat, Joel R. Phillips, Igor Keller
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Patent number: 7590518Abstract: Method of forming a reduced model of a circuit. A circuit parameter is selected, and a plurality of values for the parameter are selected. A circuit or operator equation is solved for the selected plurality of values to generate a result. The acts of selecting parameter and its plurality of values and solving the equation are repeated to generate sufficient results to form a reduced model. For each iteration, a rank revealing factorization is performed on the matrix for use in determining whether a sufficient number of results or vectors have been generated to form the reduced model so as to form a reduced model. In the plurality of values for a selected parameter, there may exist large deviation between two of the plurality of values for a selected parameter, and such deviation need not be based upon a nominal point or deviation thereof.Type: GrantFiled: September 2, 2004Date of Patent: September 15, 2009Assignee: Cadence Design Systems, Inc.Inventor: Joel R. Phillips
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Publication number: 20090210202Abstract: Described is a process for performing an improved mixed frequency-time algorithm to simulate responses of a circuit that receives a periodic sample signal and at least one information signal. The process selects a set of evenly spaced distinct time points and a set of reference time points. Each of the reference points is associated with a distinct time point, and a reference time point is a signal period away from its respective distinct time point. The process finds a first set of relationships between the values at the distinct time points and the values the reference time points. The process also finds a second set of relationships between the values at the distinct time points and the values at the reference time points. The process then combines the first and second sets of relationships to establish a system of nonlinear equations in terms of the values at the distinct time points only. By solving the system of nonlinear equations, the process finds simulated responses of the circuit in time domain.Type: ApplicationFiled: February 17, 2009Publication date: August 20, 2009Applicant: CADENCE DESIGN SYSTEMS, INC.Inventors: Dan Feng, Joel R. Phillips, Kenneth Kundert
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Patent number: 7533359Abstract: An improved method, system, and computer program product is disclosed for predicting the geometric model of transistors once manufacturing and lithographic process effects are taken into consideration. This provides a much more accurate approach for modeling transistors since it is the actual expected geometric shapes that are analyzed, rather than an idealized model of the layout that does not accurately correspond to the actual manufactured IC product. The expected geometric shape includes systematic variations, which can be determined based on the layout, and the expected random variations, which can be determined based on the lithographic process.Type: GrantFiled: May 19, 2006Date of Patent: May 12, 2009Assignee: Cadence Design Systems, Inc.Inventors: Louis K. Scheffer, Joel R. Phillips
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Patent number: 7493240Abstract: Described is a process for performing an improved mixed frequency-time algorithm to simulate responses of a circuit that receives a periodic sample signal and at least one information signal. The process selects a set of evenly spaced distinct time points and a set of reference time points. Each of the reference points is associated with a distinct time point, and a reference time point is a signal period away from its respective distinct time point. The process finds a first set of relationships between the values at the distinct time points and the values at the reference time points. The process also finds a second set of relationships between the values at the distinct time points and the values at the reference time points. The process then combines the first and second sets of relationships to establish a system of nonlinear equations in terms of the values at the distinct time points only. By solving the system of nonlinear equations, the process finds simulated responses of the circuit in time domain.Type: GrantFiled: May 15, 2000Date of Patent: February 17, 2009Assignee: Cadence Design Systems, Inc.Inventors: Dan Feng, Joel R. Phillips, Kenneth Kundert