Abstract: An improved method and system for performing extraction on an integrated circuit design is disclosed. Extraction may be performed at granularities much smaller than the entire IC design, in which a halo is used to identify a geometric volume surrounding an object of interest to identify neighboring objects and generate an electrical model. The extraction approach can be taken for Islands, Nets, as well as other granularities within the design. Re-extraction of a design can occur at granularities smaller than a net. Some approaches utilize Island-stitching to replace an island within a net. An approach is also described for improving cross-references for cross-coupled objects.
Type:
Grant
Filed:
January 7, 2011
Date of Patent:
January 21, 2014
Assignee:
Cadence Design Systems, Inc.
Inventors:
Eric Nequist, Richard Brashears, Matthew A. Liberty, Michael C. McSherry
Abstract: Systems, methodologies and technologies for the analysis and transformation of integrated circuit layouts using situations are disclosed. A method for transforming an integrated circuit (IC) layout includes recognizing shapes within the IC layout, identifying features for each of the shapes and extracting situations for the respective features. Extracted situations can be used to improve optical proximity correction (OPC) of the IC layout. This improved OPC includes extracting the situations, simulating the situations to determine a set of the situations identified for modification based on failing to satisfy a desired OPC tolerance level, modifying the set of situations to improve satisfaction of the desired OPC tolerance level, and reintegrating the modified set of situations into the IC layout. Extracted situations can also be used to improve aerial image simulation of the IC layout.
Type:
Grant
Filed:
December 22, 2009
Date of Patent:
January 14, 2014
Assignee:
Cadence Design Systems, Inc.
Inventors:
Frank E. Gennari, Ya-Chieh Lai, Matthew W. Moskewicz, Michael C. Lam, Gregory R. McIntyre
Abstract: 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:
Grant
Filed:
December 30, 2010
Date of Patent:
January 14, 2014
Assignee:
Cadence Design Systems, Inc.
Inventors:
Vinod Kariat, Joel R. Phillips, Igor Keller
Abstract: The subject application relates to a method and system for power delivery network analysis. The present disclosure is directed towards a computer-implemented method for analyzing a power delivery network (PDN) associated with an electronic circuit design. Embodiments may include extracting, using at least one processor, an electromagnetic (EM) model for each of one or more discontinuity structures associated with the circuit design and generating a three dimensional adaptive mesh model that is based upon, at least in part, the extracted EM model. Numerous other features are also within the scope of the present disclosure.
Abstract: A method and mechanism is disclosed for identifying and tracking nets in an electrical design. A hierarchical design does not have to be flattened to perform the operation of identifying and tracking nets. To identify sets of connected shapes, instead of having to unfold the entire design hierarchy, only the specific instances of shapes falling within the geometric bounds of shapes identified as being part of a net needs to be unfolded to perform the search. When composing the list of nets for a hierarchical design, the unfolded shapes at other hierarchical levels of the design can be derived based upon virtual terminal structures that implicitly references nets and objects at other levels.
Abstract: An invention is provided for dynamically configurable error correction. The invention includes receiving a check code configuration signal, which indicates a particular level of error detection. A check code generator is configured to generate check codes based on the particular level of error detection indicated by the check code configuration signal. In addition, an error locator configuration signal is received that indicates a particular level of error addressing, and an error locator is configured to produce addresses of errors in a set of data based on the particular level of error addressing indicated by the error locator configuration signal.
Abstract: A method and system for generating design constraints for an electronic circuit design is disclosed. The method and system include reading a design description and an existing design constraint file, configuring design constraint integration rules, writing a new design constraint file, evaluating results of the new design constraint file, and replacing existing design constraint file with the new design constraint file.
Type:
Grant
Filed:
June 13, 2011
Date of Patent:
January 7, 2014
Assignee:
Cadence Design Systems, Inc.
Inventors:
Manish Pandey, Marcalo Glusman, Angela Krstic, Yee-Wing Hsieh, Andy Lin
Abstract: A system, method, and computer program product is disclosed that recycle digital assertions for analyzing the test vectors to quickly and accurately calculate the switching activity at each test clock pulse or scan cycle. According to some approaches, load vector data and unload vector data are analyzed to determine toggle counts and switching activity, without requiring simulation to be performed.
Abstract: Systems, apparatus, and methods of timing analysis with a multi-operating region gate model are disclosed, including modeling a logic gate with a constant direct current (DC) voltage source during a steady state region of operation; in response to a transition from the steady state region of operation, modeling the logic gate with a time-varying voltage dependent current source during a varying current region of operation; and, in response to a transition from the variable current region of operation, modeling the logic gate with a time-invariant voltage dependent current source during an asymptotic region of operation. Instantaneous output current provided by the time varying voltage dependent current source in the VCR region is responsive to time and the instantaneous output voltage of the logic gate. Instantaneous output current provided by the time-invariant voltage dependent current source in the AR region is responsive to the instantaneous output voltage of the logic gate.
Abstract: A method is provided that comprises a circuit design that includes multiple design blocks; a power intent specification file that defines a power domain within the circuit design and that identifies design instances within the power domain and that defines a control function to selectively transition the defined power domain between multiple respective power supply values; using a digital simulator to simulate operation of the digital representation while using an analog simulator to simulate operation of the analog representation; wherein simulating the digital representation includes transitioning the defined power domain between supply values from among the multiple respective supply values; wherein simulating the analog representation includes periodically storing in a storage location a power supply value currently in use during digital simulation of the digital representation; and wherein simulating the analog representation includes using the stored currently in use power supply value to supply voltage
Type:
Application
Filed:
June 14, 2012
Publication date:
December 19, 2013
Applicant:
Cadence Design Systems, Inc.
Inventors:
Qingyu Lin, Prabal Kanti Bhattacharya, Nan Zhang, Zhong Fan
Abstract: Techniques are presented for determining effects of process variations on the leakage of an integrated circuit having multiple devices. The operation of the circuit is simulated using a first set of values for the process parameters for the devices and is also simulated with some of the process parameter values varied. For the simulation with the varied values, the circuit is split up into distinct components (such as channeled coupled components, CCCs), where each component has one or more devices, and a process parameters value in a device in each of two or more of these components is varied.
Abstract: Techniques are provided to allow users of Electronic Design Automation (EDA) tools to define constraint template types for efficiently associating constraints with design objects to specify design intent. Processes for creating and validating the constraints are provided by user-defined plug-ins, thereby allowing users to annotate circuit designs with constraints for proprietary layout and fabrication processes without exposing the constraints to tool vendors or competitors. The constraints are re-created from the template types whenever the circuit design is loaded into the EDA tool, so that the constraints are based upon the latest version of the template type. The constraints are also re-created when validation fails. Constraint groups are reusable in different designs, technology nodes, and processes because they automatically expand to provide the specific constraints to achieve a goal.
Abstract: A hardware emulation system having a heterogeneous cluster of processors is described. The apparatus for emulating a hardware design comprises a plurality of processors, where each processor performs a different function during an emulation cycle. The method performed by the apparatus comprises using a data fetch processor to retrieve data from a data array, evaluating the retrieved data using the data fetch processor to produce an output bit, supplying the output bit to an intracluster crossbar and using a data store processor to store the output bit in the data array.
Type:
Grant
Filed:
April 11, 2006
Date of Patent:
December 17, 2013
Assignee:
Cadence Design Systems, Inc.
Inventors:
Mikhail Bershteyn, Mitchell G. Poplack, Beshara G. Elmufdi
Abstract: A method and apparatus for producing a vacuity detection report to reduce false positive verification results for digital circuits provided. In an exemplary embodiment, a design description of the digital design is generated. From the design description, a vacuity detection problem is derived by introducing an assertion into the design description. By introducing an assertion into the design description, the vacuity detection problem is solvable by formal assertion based verification engines. A verification engine is then used to solve the vacuity detection problem and produce a vacuity detection report. This Abstract is provided for the sole purpose of complying with the Abstract requirement rules that allow a reader to quickly ascertain the subject matter of the disclosure contained herein. This Abstract is submitted with the explicit understanding that it will not be used to interpret or to limit the scope or the meaning of the claims.
Abstract: A user is presented with a simulation environment within which the user is provided a choice to select between parasitic simulation modes of varying accuracy, the modes including a mode without parasitics and a plurality of modes including parasitics with a varying degree of accuracy. A selection from among the modes is received from the user and simulation test are performed at the selected degree of accuracy.
Type:
Grant
Filed:
August 31, 2012
Date of Patent:
December 17, 2013
Assignee:
Cadence Design Systems, Inc.
Inventors:
Prakash Gopalakrishnan, Rongchang Yan, Akshat H. Shah, David N. Dixon, Keith Dennison
Abstract: Methods, systems, computer program products for editing electrical circuits that facilitate and speed the layout of electrical circuits. Embodiments provide high-altitude editing capabilities to the user that enable the user to more easily select circuit items in congested layouts and schematic diagrams, and modify and arrange circuit items with respect to one another in congested layouts and schematic diagrams. Additional embodiments are directed to enabling EDA commands and the like to have context sensitivity, neighborhood awareness, and/or an ability to anticipate intentions of the user.
Type:
Grant
Filed:
June 22, 2009
Date of Patent:
December 17, 2013
Assignee:
Cadence Design Systems, Inc.
Inventors:
Rajan Arora, Chayan Majumder, Sandipan Ghosh, Anil Kumar Arya
Abstract: For increasing user control and insight into preparing a mixed semiconductor design specification for simulation, there are provided methods responsive to commands that provide control over resolution of disciplines and partitioning of the design into analog and digital portions. In some aspects, the methods provide block-based assignments of disciplines, as well as design partitioning. In other aspects, the methods provide for resolving a discipline to apply in a block from among multiple possible disciplines. In some aspects, error flagging may be available for detecting disciplines different from what provided for assignment in a block. Assignments may be indicated based on instance, cell, terminal, or library names and may be specified with wild cards. In still other aspects, the methods may be embodied by instructions on computer readable media, and in systems comprising general and special purpose computer hardware that may communicate with various storage facilities and over various networks.
Type:
Application
Filed:
May 20, 2013
Publication date:
December 5, 2013
Applicant:
Cadence Design Systems, Inc.
Inventors:
Chandrashekar L. Chetput, Abhijeet Kolpekwar, Srinivasan Iyengar
Abstract: A method is provided to convert an analog mixed-signal schematic design to a digital netlist: digital blocks within the schematic design are converted to digital netlist modules; analog blocks within the schematic design are converted to analog netlist modules: at least one digital netlist module includes a first identifier for a component that is shared between at least one digital block and at least one analog block within the schematic design; an analog netlist module that corresponds to the at least one analog block within the design includes a second identifier for the shared component that is different from the first identifier; the analog netlist modules are converted to corresponding digital netlist modules; the first identifier is substituted for the second identifier in the course of translating the analog netlist module that corresponds to the at least one analog block.
Type:
Grant
Filed:
November 18, 2011
Date of Patent:
December 3, 2013
Assignee:
Cadence Design Systems, Inc.
Inventors:
Donald J. O'Riordan, Prabal Kanti Bhattacharya, Timothy Martin O'Leary
Abstract: 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:
Grant
Filed:
December 3, 2010
Date of Patent:
December 3, 2013
Assignee:
Cadence Design Systems, Inc.
Inventors:
Igor Keller, Joel R. Phillips, Jijun Chen
Abstract: An improved approach for automatically generating physical layout constraints and topology that are visually in-sync with the logic schematic created for simulation is described. The present approach is also directed to an automatic method for transferring topology from logic design to layout.