Patent application number | Description | Published |
20080306716 | Method, Apparatus and Computer Program Providing Broadband Preconditioning Based on a Reduced Coupling for Numerical Solvers - This invention relates to computing numerical solutions of linear systems of equations, specifically to implementing preconditioning of the coefficient matrix of such a system. The preconditioning applies to any coefficient matrix, dense or sparse, based on the solutions of a physical problem of unknown functions, commonly referred to as basis or interpolation functions, where the basis function spans more then one mesh element. Examples of such linear systems can result from, as examples, an electromagnetic analysis of printed circuit boards or field scattering in radar applications, fluid mechanics and acoustics. A method and system to compute a preconditioner for a coefficient matrix A that is compatible with the linear system of equations that provides basis function support over at least two mesh elements. Coupling of the preconditioner between partitions of a portioned mesh representation is only through basis functions at the partition boundaries. | 12-11-2008 |
20090037157 | Method, Apparatus and Computer Program Providing Broadband Preconditioning Based on Reduced Coupling for Numerical Solvers - This invention relates to computing numerical solutions of linear systems of equations, specifically to implementing preconditioning of the coefficient matrix of such a system. The preconditioning applies to any coefficient matrix, dense or sparse, based on the solutions of a physical problem of unknown functions, commonly referred to as basis or interpolation functions, where the basis function spans more then one mesh element. Examples of such linear systems can result from, as examples, an electromagnetic analysis of printed circuit boards or field scattering in radar applications, fluid mechanics and acoustics. A method and system to compute a preconditioner for a coefficient matrix A that is compatible with the linear system of equations that provides basis function support over at least two mesh elements. Coupling of the preconditioner between partitions of a portioned mesh representation is only through basis functions at the partition boundaries. | 02-05-2009 |
20090192776 | CHARGE-BASED CIRCUIT ANALYSIS - A solution for analyzing a circuit using initial charge information is provided. In particular, one or more nodes in a design for the circuit is initialized with an initial charge. The charge can comprise a non-equilibrium charge, thereby simulating the history effect, the impact of a charged particle, electro-static discharge (ESD), and/or the like. Operation of the circuit is then simulated over a set of input cycles based on the initial charge(s). To this extent, the non-equilibrium initial condition solution enables the state of the circuit to be controlled and solves the initial system based on these values. This capability is very useful to condition the circuit at a worst-case, best-case, and/or the like, status. Further, in one embodiment of the invention, a set of equations are provided to implement the non-equilibrium initial charge analysis, which provide a more efficient initialization of the circuit than current solutions. | 07-30-2009 |
20090193373 | MULTIPLE VOLTAGE THRESHOLD TIMING ANALYSIS FOR A DIGITAL INTEGRATED CIRCUIT - An approach for performing multiple voltage threshold timing analysis for a digital integrated circuit is described. In one embodiment, there is a multiple voltage threshold timing analysis tool for performing a multiple voltage threshold timing analysis of a digital integrated circuit having at least one logic gate loaded by an interconnect circuit. In this embodiment, a characterization data retrieving component is configured to obtain characterization data describing driving behavior of the at least one logic gate. An interconnect circuit model retrieving component is configured to obtain a model of the interconnect circuit. A multiple voltage threshold timing analysis component is configured to derive a sequence of crossing times for the driving point voltage waveform to advance between successive voltage thresholds. The multiple voltage threshold timing analysis component also generates a voltage waveform from the derived sequence of crossing times. | 07-30-2009 |
20100115013 | EFFICIENT COMPRESSION AND HANDLING OF MODEL LIBRARY WAVEFORMS - A system and method for waveform compression includes preprocessing a collection of waveforms representing cell and/or interconnect response waveforms and constructing a representative waveform basis using linear algebra to create basis waveforms for a larger set of waveforms. The collection waveforms are represented as linear combination coefficients of an adaptive subset of the basis waveforms to compress an amount of stored information needed to reproduce the collection of waveforms. The representation of coefficients may be further compressed by, e.g., analytic representation. | 05-06-2010 |
20110276933 | Method for Supporting Multiple Libraries Characterized at Different Process, Voltage, and Temperature Points - A method for accurately performing a timing, power, and noise analysis by pre-processing the characterization points of the available libraries, storing time consuming parts of the analysis and utilizing the pre-processed information during active runs to calculate the attributes at a desired PVT point. The PVT space is preferably sub-divided into triangular or rectangular regions, preferably obtained using Delaunay triangulation. In one embodiment, the invention performs an up-front pre-processing step on the characterized libraries to compute the static portion of the interpolation function that is independent of the specific instance; and a coefficient matrix that allows for interpolation of specific instances. | 11-10-2011 |
20120124542 | Method and System for Optimizing a Device With Current Source Models - A method for optimizing a circuit includes at least a first branch and a second branch includes defining an objective function using a shape of waveforms measured at a timing point in each branch, and optimizing the objective function to minimize a variance of clock skew of the first branch and the second branch across different process voltage temperature values. | 05-17-2012 |
20120143582 | CHARACTERIZATION OF NONLINEAR CELL MACRO MODEL FOR TIMING ANALYSIS - A system, method and computer program product for modeling a semiconductor device structure. The system and method implemented includes performing a simulation of the circuit by applying at least one input waveform on a circuit input port, and loading an output port with at least one of output load; determining, at successive time steps of the circuit simulation, a voltage value Vi on the input port, a voltage value Vo on the output port, and a current values (ia) and (ib) on the respective input and output ports. Then there is computed from the respective current value for each successive time step of the simulation, at least one charge value (Qa(Vi, Vo)) and (Qb(Vi, Vo)), respectively, as a function of Vi and Vo voltage values; and generating a nonlinear charge source from the at least one charge value, the nonlinear charge source used in modeling a dynamic behavior of the cell. A voltage controlled charge source (VCCS) is thereby determined by capturing the natural digital circuit cell behavior. | 06-07-2012 |
20120245904 | WAVEFORM-BASED DIGITAL GATE MODELING FOR TIMING ANALYSIS - In one embodiment, the invention is a method and apparatus for waveform-based digital gate modeling for timing analysis. One embodiment of a method for modeling a gate of an integrated circuit chip includes building a transform matrix that indexes each input waveform/output waveform pair in a gate library to a plurality of different capacitive loads, obtaining an input waveform and a capacitive load associated with the gate, and, mapping the input waveform and the capacitive load to an output waveform for the gate, in accordance with the transform matrix. | 09-27-2012 |
20130096976 | COST-EFFECTIVE AND RELIABLE UTILITIES DISTRIBUTION NETWORK - A method, system, and computer program product for designing a cost-effective and reliable distribution network for a utility are provided in the illustrative embodiments. A graph connecting a set of consumers of the utility with a set of suppliers of the utility is reduced to form a plurality of clusters. A first network between a supplier and a subset of consumers in a first cluster in the plurality of clusters is improved, the improving adding a first connection in the first network to provide continuity of supply of the utility to the subset of consumers after a predetermined number of failures in the first network. A design is generated for a second network connecting the set of suppliers to the set of consumers, the second network including the first network after the improving, wherein the second network has a cost that is within a lower threshold and an upper threshold. | 04-18-2013 |
20130116985 | ON-DEMAND TABLE MODEL FOR SEMICONDUCTOR DEVICE EVALUATION - An on-demand table model for semiconductor device evaluation is provided. A method of providing on-demand table models for semiconductor device evaluation, includes measuring one or more measurement values of an instance of a semiconductor device. The method further includes providing, by a processor, a table model of the instance for the semiconductor device evaluation upon receiving a request for the semiconductor device evaluation. The method further includes generating a table entry in the table model for the one or more measurement values, the table entry including one or more evaluation values of an evaluation function for the instance. | 05-09-2013 |
20140297233 | AUTOMATIC CALIBRATION OF A MODEL FOR A COMPLEX FLOW SYSTEM - Aspects of the present invention provide a solution for calibrating a model of a complex flow system. In an embodiment, a comparison is made between the output from the model and a set of observed values for each of a plurality of nodes in the complex flow system. An adjoint sensitivity is computed for each of the nodes based on the comparison. These computed adjoint sensitivities are used to adjust a set of coefficients of the models. This calibration process can be performed multiple times, periodically and/or continuously to maximize the accuracy of the model. | 10-02-2014 |
20150046891 | Cross-Talk Noise Computation Using Mixed Integer Linear Program Problems And Their Solutions - A method includes forming a mixed integer linear problem (MILP) capturing at least a plurality of timing windows over which aggressor net(s), electromagnetically coupled to a victim net in a circuit, produce computed cross-talk noise pulses potentially contributing to a maximum noise for the victim net. The MILP is solved to determine the maximum noise at the victim net. Responsive to the maximum noise meeting one or more criteria, at least an indication of the victim net is output. Forming may include forming a linear problem using overlapping timing windows for which noise pulses contribute to the maximum noise and converting the linear problem to the mixed integer linear problem by introducing into the linear problem binary variables that determine whether individual ones of overlapping or non-overlapping noise pulses from the one or more aggressor nets contribute to the maximum noise. Apparatus and program products are also disclosed. | 02-12-2015 |
20150046892 | Cross-Talk Noise Computation Using Mixed Integer Linear Program Problems And Their Solutions - A method includes forming a mixed integer linear problem (MILP) capturing at least a plurality of timing windows over which aggressor net(s), electromagnetically coupled to a victim net in a circuit, produce computed cross-talk noise pulses potentially contributing to a maximum noise for the victim net. The MILP is solved to determine the maximum noise at the victim net. Responsive to the maximum noise meeting one or more criteria, at least an indication of the victim net is output. Forming may include forming a linear problem using overlapping timing windows for which noise pulses contribute to the maximum noise and converting the linear problem to the mixed integer linear problem by introducing into the linear problem binary variables that determine whether individual ones of overlapping or non-overlapping noise pulses from the one or more aggressor nets contribute to the maximum noise. Apparatus and program products are also disclosed. | 02-12-2015 |