Patents Examined by Leigh Marie Garbowski
  • Patent number: 8060847
    Abstract: An edge clock model is used to capture states from a logic-level simulation of a circuit description. The states are captured at clock edges, or transitions, according to an edge clock model based on a clock specification for the circuit description. The captured states and associated attributes are used in formal verification of the circuit description. This approach helps to reduce or eliminate inaccuracies and other issues with other clock models such as a phase clock model. In one embodiment, a phase clock model can be used in addition to the edge clock model. In another embodiment, the edge clock states can be used to generate states according to different clock models, such as the phase clock model.
    Type: Grant
    Filed: December 23, 2008
    Date of Patent: November 15, 2011
    Assignee: Mentor Graphics Corporation
    Inventors: James Andrew Garrard Seawright, Jeremy Rutledge Levitt, Christophe Gauthron
  • Patent number: 8020132
    Abstract: Combined memories in integrated circuits are described, including determining a first requirement for logic blocks, determining a second requirement for memory blocks including a vertical configuration for the memory blocks, and compiling a design for the integrated circuit using the first requirement and the second requirement. The memory blocks may include non-volatile two-terminal cross-point memory arrays. The non-volatile two-terminal cross-point memory arrays can be formed on top of a logic plane. The logic plane can be fabricated in a substrate. The non-volatile two-terminal cross-point memory arrays may be vertically stacked upon one another to form a plurality of memory planes. The memory planes can be portioned into sub-planes. One or more different memory types such as Flash, SRAM, DRAM, and ROM can be emulated by the plurality of memory planes and/or sub-planes. The non-volatile two-terminal cross-point memory arrays can include a plurality of two-terminal memory elements.
    Type: Grant
    Filed: December 19, 2007
    Date of Patent: September 13, 2011
    Inventor: Robert Norman
  • Patent number: 8020120
    Abstract: A method for layout design includes steps or acts of: receiving a layout for design of an integrated circuit chip; designing mask shapes for the layout; transmitting the mask shapes to a litho simulator for generating wafer shapes; receiving the wafer shapes; calculating electrically equivalent gate lengths for the wafer shapes; analyzing the gate lengths to check for conformity against a threshold value, wherein the threshold value represents a desired value of electrically equivalent gate lengths; placing markers on the layout at those locations where the gate length violates the threshold value; and generating a histogram of gate lengths for comparing layouts for electrically equivalent gate lengths for layout quality.
    Type: Grant
    Filed: October 1, 2007
    Date of Patent: September 13, 2011
    Assignee: International Business Machines Corporation
    Inventors: Fook-Luen Heng, Mark A. Lavin, Jin-Fuw Lee, Thomas Ludwig, Rama Nand Sing, Fanchieh Yee
  • Patent number: 8015527
    Abstract: The invention relates to a delay calculation method for wiring nets of an electronic circuit, wherein a net within an electronic circuit comprises a driver pin and a receiving pin being coupled by at least one loop, the loop comprising a first branching path and a second branching path electrically parallel to the first branching path, wherein at least a first and a second branching point connect the branching paths. The method comprises the steps of disconnecting each branching path once at a time at a specific point in said the at least one loop which connects a driver to at least one specific receiving pin; calculating a delay value of a signal connection between the driver pin and each of the receiving pin for each of the disconnected branching paths of each loop; storing maximum and/or minimum calculated delay values; and applying at least one of the delay values for static timing analysis of the electronic circuit.
    Type: Grant
    Filed: July 1, 2008
    Date of Patent: September 6, 2011
    Assignee: International Business Machines Corporation
    Inventors: Markus Buehler, Juergen Koehl, Markus Olbrich, Philipp Panitz
  • Patent number: 8010922
    Abstract: Buffers are placed on selected nets coupled to input and output pins of entities in an IC device. This includes loading selected input and output pins of entities prior to respectively buffering nets of the entities and buffering in successive iterations, which includes setting artificial loads on selected input pins. The buffering in a current iteration is limited to i) buffering nets on the current iteration entity for receivers on the current iteration entity and ii) buffering nets on the current iteration entity directly coupled to respective nets of an immediately adjacent entity that has been buffered already in a preceding one of iterations, but only if the already buffered net is coupled to a receiver on its own net or a receiver on some other already buffered net via nets that have all been buffered via one or more of the preceding iterations.
    Type: Grant
    Filed: February 18, 2008
    Date of Patent: August 30, 2011
    Assignee: International Business Machines Corporation
    Inventors: Frank Malgioglio, Adam R. Jatkowski, Brian A. Lasseter, Joseph J. Palumbo
  • Patent number: 8006213
    Abstract: A design methodology and algorithms for the computer aided design of integrated circuits having clock distribution networks. The clustering of latch distribution tree components is combined with repositioning of such components within clock sector areas. The movement and clustering of components is such that the timing constraints are preserved. The methods is described in terms of reducing and balancing the load inside each clock sector, although the techniques may also be applied to balancing load between clock sectors.
    Type: Grant
    Filed: February 15, 2008
    Date of Patent: August 23, 2011
    Assignee: International Business Machines Corporation
    Inventors: Christopher J. Berry, Jose Luis Pontes Correla Neves, Charlie Chornglii Hwang, David Wade Lewis
  • Patent number: 8001492
    Abstract: A design and evaluation method for interconnect wires of integrated circuits is provided to detect, analyze and predict response of interconnect layout to integrated-circuit manufacture processes.
    Type: Grant
    Filed: June 27, 2008
    Date of Patent: August 16, 2011
    Assignee: Linden Design Technologies, Inc.
    Inventor: Wallace W. Lin
  • Patent number: 8001515
    Abstract: An analog system consists of a multitude of interconnected components. Design of such a system involves optimization of the component parameters to achieve a target behavior, collectively called specification. The present invention provides a generic cost function for analog design optimization. It also provides cost surface modeling to speed up the optimization. The cost function compares the behavior of a design to a quantitative specification, which can be a ‘golden’ reference behavior (specification), and measures the error cost, an index of the behavioral discrepancy. That is, the target behavior is explicitly embedded in the cost function. By using the cost function, one can readily qualify a design and thereby identify good/optimum designs.
    Type: Grant
    Filed: December 21, 2007
    Date of Patent: August 16, 2011
    Assignee: National Semiconductor Corporation
    Inventor: Jang Dae Kim
  • Patent number: 8001508
    Abstract: A method for optimizing pin selection for an integrated circuit is provided. Pin locations are mapped to a vector. The mutual inductive relationships between pins of the integrated circuit are captured into a matrix. The matrix contains the data of how a signal state of each pin is affected by the toggling of other pins within the I/O bank. The pin locations and the crosstalk matrix are combined to characterize the impact of the crosstalk on the pins for the pin placement. Thereafter, a user may decide to alter the pin placement or alter the sampling interval for the pin to avoid sampling the pin when the crosstalk may affect the signal integrity. The method may be applied for multiple simultaneous switching noise cause mechanisms impacting the signal integrity. In this embodiment, a worst case cause mechanism from the individually quantified cause mechanisms is determined by comparing an impact of each of the cause mechanisms.
    Type: Grant
    Filed: October 23, 2007
    Date of Patent: August 16, 2011
    Assignee: Altera Corporation
    Inventors: Nafira Daud, Geping Liu, San Wong, Lawrence David Smith
  • Patent number: 7987434
    Abstract: A system for calculating mask data to create a desired layout pattern on a wafer reads all or a portion of a desired layout pattern. Mask data having pixels with transmission values is defined along with corresponding optimal mask data pixel transmission values. An objective function is defined that compares image intensities as would be generated on a wafer with an optimal image intensity at a point corresponding to a pixel. The objective function is minimized to determine the transmission values of the mask pixels that will reproduce the desired layout pattern on a wafer.
    Type: Grant
    Filed: January 23, 2009
    Date of Patent: July 26, 2011
    Assignee: Mentor Graphics Corporation
    Inventors: Yuri Granik, Kyohei Sakajiri
  • Patent number: 7987439
    Abstract: Provided are a method and apparatus for analyzing a circuit model by reducing, and a computer program product for analyzing the circuit model. The circuit model at least includes independent current source models, resistance models, and capacitance models. Also, the circuit model forms a resistance capacitance (RC) network with independent current sources. The method includes selecting a node to be removed using resistance information and comparing conductance of a capacitor for a given time step and the total conductance of the node. Further, the method includes removing the selected nodes and generating RC elements and independent current sources using adjacent nodes, which maintain the accuracy of node voltages of a circuit reduced in an accuracy order used for entrywise perturbation of the corresponding circuit equation. Moreover, an efficient method of handling the independent current sources while reducing the circuit is provided.
    Type: Grant
    Filed: February 7, 2008
    Date of Patent: July 26, 2011
    Assignee: Postech Academy-Industry Foundation
    Inventors: Hong Bo Che, Young Hwan Kim
  • Patent number: 7987435
    Abstract: A verification method of an integrated circuit pattern includes extracting a pattern which is not greater than a preset pattern size, extracting a pattern edge as a target of lithography simulation from the extracted pattern, and performing the lithography simulation on the extracted pattern edge to verify the integrated circuit pattern.
    Type: Grant
    Filed: September 2, 2009
    Date of Patent: July 26, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Ryuji Ogawa, Koji Hashimoto
  • Patent number: 7984395
    Abstract: A method of increasing hierarchy compression of a metal 1 standard cell layout during optical proximity correction (OPC) is provided. This method can use a context determination defined from the outermost OPC correctable-edge boundaries of a metal 1 standard cell and not extending past outermost OPC correctable edge boundaries of adjacent metal 1 standard cells in other rows. The method can also include (or can alternatively include) adjusting the landing pads (resulting from metal 2 placement) to fit within the lines of the metal 1 standard cell layout. This adjusting can be performed by a place and route tool as part of a “clean-up” operation after metal 2 placement. The landing pads can be sized for single or double vias. A layout design for the metal 1 standard cell layout can be output based on using the context determination and/or adjusting the landing pads for hierarchy compression.
    Type: Grant
    Filed: January 17, 2008
    Date of Patent: July 19, 2011
    Assignee: Synopsys, Inc.
    Inventor: Christopher M. Cork
  • Patent number: 7984406
    Abstract: A computer-implemented timing verification method for obtaining delay time for a signal propagated through a signal path and performing timing verification. The method stores a table including a wiring resistance variation amount and a wiring capacitance variation amount that are in accordance with a geometry deviation of a wire from a reference geometry, extracts a wiring structure of the signal path from a storage unit, extracts a wiring resistance variation amount and a wiring capacitance variation amount that correspond to the extracted wiring structure from the table, generates an on-chip-variation coefficient from the extracted wiring resistance variation amount and wiring capacitance variation amount, and calculates delay time for the signal propagated through the signal path based on the generated on-chip-variation coefficient.
    Type: Grant
    Filed: January 22, 2008
    Date of Patent: July 19, 2011
    Assignee: Fujitsu Semiconductor Limited
    Inventors: Takeichirou Akamine, Toshikatsu Hosono
  • Patent number: 7979834
    Abstract: A computer-implemented method of predicting timing characteristics within a semiconductor device can include determining configuration information for the semiconductor device and determining a measure of timing degradation for data signals of the semiconductor device according to the configuration information. The measure of timing degradation for the data signals can be output.
    Type: Grant
    Filed: January 24, 2008
    Date of Patent: July 12, 2011
    Assignee: Xilinx, Inc.
    Inventor: Anthony T. Duong
  • Patent number: 7979835
    Abstract: A method of estimating resource requirements for a circuit design is disclosed. The method comprises identifying intermediate circuit modules of a netlist associated with the circuit design; accessing a library of resource requirements for intermediate circuit modules of netlists for circuit designs; selecting intermediate circuit modules of the library according to predetermined parameters for the circuit design; and generating an estimate of resource requirements for the circuit design based upon resource requirements of the selected intermediate circuit modules.
    Type: Grant
    Filed: March 3, 2008
    Date of Patent: July 12, 2011
    Assignee: Xilinx, Inc.
    Inventors: Paul R. Schumacher, Ian D. Miller, David B. Parlour, Jorn W. Janneck, Pradip Kumar Jha
  • Patent number: 7975253
    Abstract: An object is to simplify a power supply noise analysis model of a circuit board. CAD data of the circuit board is obtained from a CAD apparatus, and overlapping power supply islands among power supply islands existing in different layers of the circuit board are extracted as a power supply pair. Nodes are arranged in the extracted power supply pair, and the nodes of the power supply pair are projected on the power supply islands to which the power supply pair belongs. A mesh region which encloses each node is determined for each power supply island, and impedance (L, R, C) between nodes is calculated. Then, a power supply noise analysis model is created based on the impedance between nodes in each layer, and a capacitance between layers.
    Type: Grant
    Filed: September 28, 2007
    Date of Patent: July 5, 2011
    Assignee: Fujitsu Limited
    Inventors: Yoshiyuki Iwakura, Shogo Fujimori, Tendou Hirai, Hitoshi Chida, Kazuyoshi Kanei, Koutarou Nimura
  • Patent number: 7971177
    Abstract: A method for simulating operation of a charge trapping memory cell which computes the amount of charge trapped by determining first tunneling current through the tunneling layer, determining second tunneling current out of the charge trapping layer to the gate, determining third tunneling current escaping from traps in the charge trapping layer and tunneling out to the gate, and integrating said tunneling currents over a time interval. A change in threshold voltage can be computed for a transistor including the charge trapping structure. The parameter set can include only physical parameters, including layer thickness, band offsets and dielectric constants.
    Type: Grant
    Filed: July 30, 2008
    Date of Patent: June 28, 2011
    Assignee: Macronix International Co., Ltd.
    Inventors: Shaw Hung Ku, Chia Wei Wu, Ming Shang Chen, Wenpin Lu
  • Patent number: 7971163
    Abstract: Disclosed is a property generating apparatus which generates a property representing a specification of an integrated circuit and verifying design information on the integrated circuit described in RTL (Register Transfer Level). The property generating apparatus includes: a storage unit, which stores a register name to identify a register; an address expanding unit, which expands property abbreviated description information on a group of registers including the register, and generates a group of addresses; an RTL analysis unit, which selects a group of register names from the register name stored in the storage unit; and a property generation unit, which generates the property by correlating the group of addresses with the group of register names.
    Type: Grant
    Filed: February 24, 2009
    Date of Patent: June 28, 2011
    Assignee: NEC Corporation
    Inventor: Atsuko Goto
  • Patent number: 7966586
    Abstract: The present invention is directed to an improved method, system, and computer program product for accessing and analyzing patterns in the integrated circuit design. The method, system or computer program product includes generating an intelligent signature for a pattern. The derived pattern signature is an intelligent pattern identifier because it retains only essential information about a pattern that corresponds to lithography printable portions of the pattern. Accordingly, one pattern signature can represent a group of design patterns that are equivalents from a lithography perspective.
    Type: Grant
    Filed: December 7, 2007
    Date of Patent: June 21, 2011
    Assignee: Cadence Design Systems, Inc.
    Inventors: Junjiang Lei, Kuang-Hao Lay, Srini Doddi, Weiping Fang