Patents Assigned to Cadence Design System, Inc.
  • Patent number: 7383524
    Abstract: Some embodiments of the invention provide a method for pre-tabulating sub-networks. This method (1) generates a sub-network that performs a function, (2) generates a parameter based on this function, and (3) stores the sub-network in a storage structure based on the generated parameter. In some embodiments, the generated sub-network has several circuit elements. Also, in some embodiments, the generated sub-network performs a set of two or more functions. Some embodiments store each generated sub-network in an encoded manner. Some embodiments provide a method for producing a circuit description of a design. This method (1) selects a candidate sub-network from the design, (2) identifies an output function performed by the sub-network, (3) based on the identified output function, identifies a replacement sub-network from a storage structure that stores replacement sub-networks, and (4) replaces the selected candidate sub-network with the identified replacement sub-network in certain conditions.
    Type: Grant
    Filed: January 31, 2002
    Date of Patent: June 3, 2008
    Assignee: Cadence Design Systems, Inc
    Inventors: Steven Teig, Asmus Hetzel
  • Publication number: 20080126999
    Abstract: Method and system for conducting low-power design explorations are disclosed. The method includes receiving an RTL netlist of a circuit design, creating one or more power requirement files, wherein each power requirement file comprises power commands corresponding to the RTL netlist, generating one or more low-power RTL netlists using the corresponding one or more power requirement files and the RTL netlist, and conducting low-power design explorations using the one or more low-power RTL netlists.
    Type: Application
    Filed: October 26, 2006
    Publication date: May 29, 2008
    Applicant: Cadence Design Systems, Inc.
    Inventor: Qi Wang
  • Publication number: 20080127014
    Abstract: Method and system for equivalence checking of a low power design are disclosed. The method includes receiving a register-transfer level (RTL) netlist representation of a circuit, receiving a power specification file for describing power requirements of the circuit, creating a low power gate netlist for representing a design implementation of the circuit using the RTL netlist and the power specification file, creating a reference low power RTL netlist for representing a design specification of the circuit using the RTL netlist and the power specification file, and performing equivalence checking between the low power gate netlist and the reference low power RTL netlist. The method further includes annotating low power information described in the power specification file into the reference low power RTL netlist, and creating low power logic in the reference low power RTL netlist.
    Type: Application
    Filed: October 25, 2006
    Publication date: May 29, 2008
    Applicant: Cadence Design Systems, Inc.
    Inventors: Manish Pandey, Rajat Arora, Chih-Chang Lin, Huan-Chih Tsai, Bharat Chandramouli, Kei-Yong Khoo
  • Patent number: 7380226
    Abstract: A method and an apparatus to perform logic synthesis preserving high-level specification and to check that a common specification (CS) of two circuits is correct have been disclosed. In one embodiment, the method includes building a circuit N2 that preserves a predefined specification of a circuit N1. In some embodiments, the method includes verifying that N2 and N1 indeed implement the same specification and so they are functionally equivalent.
    Type: Grant
    Filed: December 29, 2004
    Date of Patent: May 27, 2008
    Assignee: Cadence Design Systems, Inc.
    Inventor: Evgueni I. Goldberg
  • Patent number: 7380220
    Abstract: A method and system are described to reduce process variation as a result of the electrochemical deposition (ECD), also referred to as electrochemical plating (ECP), and chemical mechanical polishing (CMP) processing of films in integrated circuit manufacturing processes. The described methods use process variation and electrical impact to direct the insertion of dummy fill into an integrated circuit.
    Type: Grant
    Filed: September 22, 2004
    Date of Patent: May 27, 2008
    Assignee: Cadence Design Systems, Inc.
    Inventors: Taber H. Smith, Vikas Mehrotra, David White
  • Publication number: 20080116397
    Abstract: A method and system for particle beam lithography, such as electron beam (EB) lithography, is disclosed. The method and system include selecting one of a plurality of cell patterns from a stencil mask and partially exposing the cell pattern to a particle beam, such as an electron beam, so as to selectively project a portion of the cell pattern on a substrate.
    Type: Application
    Filed: November 21, 2006
    Publication date: May 22, 2008
    Applicant: Cadence Design Systems, Inc.
    Inventors: Kenji Yoshida, Takashi Mitsuhashi, Shohei Matsushita, Akira Fujimura
  • Publication number: 20080120073
    Abstract: A method and system for lithography simulation is disclosed. The method and system specify a subject region of a lithography image with a CD marker, specify a threshold intensity over the lithography image, specify a gradient to a threshold value of the threshold intensity, and calculate a sensitivity or ratio of change of an image boundary of the lithography image to lithography process variation.
    Type: Application
    Filed: November 21, 2006
    Publication date: May 22, 2008
    Applicant: Cadence Design Systems, Inc.
    Inventors: Daisuke Hara, Takashi Mitsuhashi, Zhigang Wu
  • Publication number: 20080120083
    Abstract: A system and method for modeling an IC (integrated circuit) employs a mesh model and a grid model for separating impedance effects between nearby and far-away pairs of mesh elements. Models for relating currents and voltages can be incrementally adapted from other designs or design elements in applications including mixed-signal, analog and RF (radio frequency) circuits.
    Type: Application
    Filed: November 17, 2006
    Publication date: May 22, 2008
    Applicant: Cadence Design Systems, Inc.
    Inventors: Enis A. Dengi, Feng Ling, Ben Song, Warren Harris
  • Publication number: 20080116398
    Abstract: A method of particle beam lithography includes selecting at least two cell patterns from a stencil, correcting proximity effect by dose control and by pattern modification for the at least two cell patterns, and writing the at least cell two patterns by one shot of the particle beam after proximity effect correction (PEC).
    Type: Application
    Filed: November 21, 2006
    Publication date: May 22, 2008
    Applicant: Cadence Design Systems, Inc.
    Inventors: Daisuke Hara, Katsuo Komuro, Takashi Mitsuhashi
  • Publication number: 20080116399
    Abstract: A method for particle beam lithography, such as electron beam (EB) lithography, includes forming a plurality of cell patterns on a stencil mask and shaping one or more of the cell patterns with a polygonal-shaped contour. A first polygonal-shaped cell pattern is exposed to a particle beam so as to project the first polygonal-shaped cell pattern on a substrate. A second polygonal-shaped cell pattern, having a contour that mates with the contour of the first polygonal-shaped cell pattern, is exposed to the particle beam, such as an electron beam, so as to project the second polygonal-shaped cell pattern adjacent to the first polygonal-shaped cell pattern to thereby form a combined cell with the contour of the first polygonal-shaped cell pattern mated to the contour of the second polygonal-shaped cell pattern. The polygonal-shaped contour of the first and second cell patterns may comprise a rectilinear-shaped contour.
    Type: Application
    Filed: November 21, 2006
    Publication date: May 22, 2008
    Applicant: Cadence Design Systems, Inc.
    Inventors: Akira Fujimura, James Fong, Takashi Mitsuhashi, Shohei Matsushita
  • Publication number: 20080120084
    Abstract: A system and method for modeling an IC (integrated circuit) employs a mesh model and a grid model for separating impedance effects between nearby and far-away pairs of mesh elements. Models for relating currents and voltages can be incrementally adapted from other designs or design elements in applications including mixed-signal, analog and RF (radio frequency) circuits.
    Type: Application
    Filed: November 17, 2006
    Publication date: May 22, 2008
    Applicant: Cadence Design Systems, Inc.
    Inventors: Enis A. Dengi, Feng Ling, Ben Song, Warren Harris
  • Patent number: 7373620
    Abstract: A method of extracting capacitance from a layout record includes imposing voltages on conductors in a layout record, and determining a total charge for each of the conductors to obtain a capacitor element for the conductors. A method of extracting capacitance from a layout record includes matching a configuration of conductors in a layout record against a reference pattern, and determining an extracted capacitance for the conductors based at least in part on the reference pattern. A method of extracting capacitance from a layout record includes providing a layout record of a circuit design, the layout record having data representing conductors and metal fill, and extracting capacitance to determine a set of capacitors between the conductors, the set of capacitors accounting for the metal fill.
    Type: Grant
    Filed: July 30, 2004
    Date of Patent: May 13, 2008
    Assignee: Cadence Design Systems, Inc.
    Inventor: Terrence A. Lenahan
  • Patent number: 7373289
    Abstract: Method and system for determining electrical isomorphism between two electrical networks are disclosed. In one embodiment, the method includes representing the circuit as a hierarchically-arranged set of branches. The hierarchically-arranged set of branches including a first branch that includes a first electrical network and a second branch that includes a second electrical network, where the first and second branches are interconnected in the graph through a third branch at a higher hierarchical level in the graph than the first and second branches. Next, the method determines whether the first and second electrical networks are electrically isomorphic networks. If the first and second electrical networks are determined to be electrically isomorphic networks, the first and second electrical networks are represented with a single electrically isomorphic network. The method further includes simulating the first and second electrical networks using the single electrically isomorphic network.
    Type: Grant
    Filed: November 19, 2004
    Date of Patent: May 13, 2008
    Assignee: Cadence Design Systems, Inc
    Inventors: Bruce W. McGaughy, Wai Chung William Au, Baolin Yang
  • Patent number: 7373618
    Abstract: A system, method, computer program, and article of manufacture for generating a golden circuit including datapath components for equivalence checking of synthesized revised circuit. The method includes generating a set of static, dynamic and derived candidates for the datapath component subcircuit, evaluating the similarity degree for each candidate in relation to the revised circuits and selecting one candidate for implementation in the golden circuit. As a result, the subcircuit of datapath component in the golden circuit is replaced with the subcircuit which is more similar to the revised circuit to improve the efficiency of the equivalence checking.
    Type: Grant
    Filed: November 10, 2005
    Date of Patent: May 13, 2008
    Assignee: Cadence Design Systems, Inc.
    Inventors: Kei-Yong Khoo, Tao Feng, Debjyoti Paul, Chih-Chang Lin
  • Publication number: 20080104548
    Abstract: The present invention relates to a method and system for tuning a circuit. In one embodiment, the method includes receiving a description of the circuit, and selecting a design point of the circuit for evaluation using a sizing tool, where the design point comprises a design of the circuit that meets a set of predefined design specifications, and the circuit comprises a group of circuit devices. The method further includes receiving a set of tuning information for the group of circuit devices tuning the group of circuit devices using the set of tuning information to create a group of tuned circuit devices, creating an updated layout of the group of tuned circuit devices using a layout tool, creating estimated parasitic information of the group of tuned circuit devices using the updated layout, and verifying the design point meets design goals of the circuit using the estimated parasitic information of the updated layout.
    Type: Application
    Filed: October 12, 2006
    Publication date: May 1, 2008
    Applicant: Cadence Design Systems, Inc.
    Inventors: Rongchang Yan, Prakash Gopalakrishnan
  • Publication number: 20080104557
    Abstract: Method and system are disclosed for designing a circuit using an integrated sizing, layout, and extractor tool. In one embodiment, a method for designing a circuit including initializing a set of design points, where a design point comprises a design of the circuit that meets a set of predefined design specifications, determining sizes for the circuit using a size optimization iteration process, and pausing the sizing optimization iteration process periodically for updating parasitic information of the circuit. The method further includes selecting a subset of design points from the set of design points, generating a layout of the circuit using devices sizes obtained from the set of design points, generating an extracted netlist using the layout, wherein the extracted netlist includes parasitic information of the circuit, and simulating the circuit using the extracted netlist to verify the set of predefined design specifications are met.
    Type: Application
    Filed: October 12, 2006
    Publication date: May 1, 2008
    Applicant: Cadence Design Systems, Inc.
    Inventors: Prakash Gopalakrishnan, Hongzhou Liu
  • Patent number: 7367006
    Abstract: A hierarchical, rule-based, general property visualization and editing system, method, and computer program for circuit designs is provided. A general rules dictionary is created or obtained that determines how the rules will be applied to the circuit design hierarchy. A hierarchical graphical user interface serves both as an entry means for the properties of the design components, and as a visualization means to view the resolved effective value of the property for each component or sub-hierarchy. The visualization means also provides a mechanism to view the rule resolution process so a user can view and understand the effects of all the rules that have an effect on the property and can modify the rules settings to obtain the desired effective property value. A property configuration file is output from the visualization tool and input into the simulator armed with the same general rules dictionary.
    Type: Grant
    Filed: January 11, 2005
    Date of Patent: April 29, 2008
    Assignee: Cadence Design Systems, Inc.
    Inventors: Donald J. O'Riordan, Friedrich Sendig
  • Patent number: 7367008
    Abstract: A pattern-dependent model is used to predict characteristics of an integrated circuit that is to be fabricated in accordance with a design by a process. The process includes (a) a fabrication process that will impart topographical variation to the integrated circuit and (b) a lithography or etch process, the lithography or etch process using a mask produced from the design. The lithography or etch process and the fabrication process interact to cause the predicted characteristics to differ from the design. The mask is adjusted in response to characteristics predicted by the model, to reduce the effect of the interacting of the lithography or etch process and the fabrication process.
    Type: Grant
    Filed: December 17, 2002
    Date of Patent: April 29, 2008
    Assignee: Cadence Design Systems, Inc.
    Inventors: David White, Taber H. Smith
  • Patent number: 7363598
    Abstract: A method and system are described to reduce process variation as a result of the electrochemical deposition (ECD), also referred to as electrochemical plating (ECP), and chemical mechanical polishing (CMP) processing of films in integrated circuit manufacturing processes. The described methods use process variation and electrical impact to direct the insertion of dummy fill into an integrated circuit.
    Type: Grant
    Filed: September 22, 2004
    Date of Patent: April 22, 2008
    Assignee: Cadence Design Systems, Inc.
    Inventors: Taber H. Smith, Vikas Mehrotra, David White
  • Patent number: 7363605
    Abstract: A method for analyzing a circuit design identifies a possible noise fault for a timing interval based on a timing analysis of a victim net and at least one aggressor net of the circuit design and determines whether the noise fault is feasible based on a behavioral representation of the victim net and the aggressor net for the timing interval.
    Type: Grant
    Filed: May 28, 2004
    Date of Patent: April 22, 2008
    Assignee: Cadence Design Systems, Inc.
    Inventors: Alex Kondratyev, Kenneth Tseng, Yosinori Watanabe