Abstract: In random defect yield simulation, a specific defect size interacts with a specific physical design and has a calculated probability of failure associated with it. The failure model is in terms of probability of failure. It provides a solution to the random defect yield simulation problem of chips with a built-in redundancy scheme. The solution first defines the independent failure modes of the chip with a built-in redundancy scheme and efficiently models each mode. Then, it may accumulate the respective probability of failures according to the chip's architecture.
Type:
Grant
Filed:
December 27, 2007
Date of Patent:
July 19, 2011
Assignee:
Cadence Design Systems, Inc.
Inventors:
Roland Ruehl, Mathew Koshy, Jonathan Fales, Udayan Gumaste
Abstract: An automated debugging method and system for over-constrained circuit verification environment are described. Useful information related to circuit evaluation and/or over-constrained event is collected and provided. The information may include: clock cycles at which an over-constrained event occurs; identification of a minimum subset of constraints that will cause an over-constrained event to occur; signal ports having an associated signal that can not switch between different signal states; whether a triggering signal event has occurred during the evaluation; indicating whether constraints in the evaluation are realizable, etc. Novel approaches for detecting and obtaining the useful information also are described.
Type:
Grant
Filed:
October 31, 2008
Date of Patent:
July 19, 2011
Assignee:
Cadence Design Systems, Inc.
Inventors:
Amir Lehavot, Vinaya Kumar Singh, Joezac John Zachariah, Jose Barandiaran, Axel Siegfried Scherer
Abstract: A method for determining a worst-case transition is disclosed. The method includes determining a plurality of output slews for the plurality of input signals based on a timing model of a gate and selecting a worst delay input signal from the plurality of input signals based on the output slews.
Abstract: A method for testing integrated circuits is provided. The method provides for incorporating compression and decompression logic into each sub-component of an integrated circuit, developing test modes that target different sub-components of the integrated circuit, selecting one of the test modes, applying a test pattern to one or more sub-components of the integrated circuit targeted by the one test mode, comparing a response from application of the test pattern to a known good response, and diagnosing the response to determine which part of the one or more sub-components targeted by the one test mode failed when the response does not match the known good response.
Type:
Grant
Filed:
November 1, 2007
Date of Patent:
July 12, 2011
Assignee:
Cadence Design Systems, Inc.
Inventors:
Brian Foutz, Patrick Gallagher, Vivek Chickermane, Carl Barnhart
Abstract: Method and system for locating objects in a computing grid. Requests for one or more objects are received from a client or other requesting entity. A persistent object locator is distributed across the grid and searches the grid for a reference to or handle on the requested object. The persistent object locator includes an internal object locator element (IOL) that resides locally, e.g., on the client, and an external object locator element (EOL) that resides on one or more other servers that are external relative to the client. The EOL is initiated if the IOL cannot locate the requested object locally. The EOL searches the grid for the requested object and if the object is available, delivers the reference to or handle on the requested object to the requesting entity. Objects can also be registered to the POL for future use. References to objects can also be deleted from the POL in the event of a communication failure or if a server or process terminates as expected.
Abstract: Connections between digital blocks and other circuit components, such as power supplies and clocks, are verified using a discrete property or object, such as a discrete discipline. A discrete discipline is defined for each value of an operating parameter, such as voltage or clock speed, that is used in a circuit design. Each discrete discipline is propagated throughout respective nets using bottom-up and/or top-down propagation. As a result, each digital net is associated with a power supply value through its corresponding discrete discipline. A determination is made whether two digital nets are connected to each other within the same digital island. If so, a determination is made whether the digital nets are compatible. If they have conflicting discrete disciplines, then they are not compatible and an error report or signal can be generated to identify the incompatibility and its location. Compatibility checks can disregard grounded digital nets.
Type:
Grant
Filed:
March 9, 2006
Date of Patent:
July 12, 2011
Assignee:
Cadence Design Systems, Inc.
Inventors:
Srinivasan Iyengar, Abhijeet Kolpekwar, Chandrashekar L. Chetput
Abstract: Methods for analyzing circuit distortion based on contributions from separate circuit elements are presented. Local approximations that do not require high-order derivatives of device models are developed near an operating point for calculating distortion summaries including compression summaries and second-order intermodulation (IM2) distortion summaries.
Abstract: In one embodiment, a method comprises retaining at least a portion of simulation results corresponding to a first simulateable partition from a previous simulation time; and using the simulation results for a second simulateable partition (or the first simulateable partition) at a current simulation time if the second simulateable partition is equivalent to the first simulateable partition and one or more input stimuli to the second simulateable partition at the current simulation time are approximately the same as the input stimuli to the first simulateable partition at the previous simulation time. Computer accessible media storing instructions that implement the method are also contemplated.
Abstract: Parameterized cells are cached and provided by the plug-in to increase the speed and efficiency of an application for circuit design. This allows source design to be read-interoperable and also enables some basic write-interoperability in the source design.
Type:
Grant
Filed:
June 27, 2007
Date of Patent:
June 28, 2011
Assignee:
Cadence Design Systems, Inc.
Inventors:
Arnold Ginetti, Gilles S. C. Lamant, Randy Bishop
Abstract: Techniques are present for designing of integrated circuits. Both custom design data and synthesized digital design data are received and merged into a design database in an automated process. The design database is then made accessible to layout tools so that the layout tools may operate upon it. These layout tools can include, but are not limited to, custom tools, digitals, or a combinations of these.
Abstract: Disclosed is an improved method, system, and article of manufacture for implementing routing for an electrical circuit and chip design. A routing architecture can be represented as a spectrum of different granular routing levels. Instead of routing based upon area, routing can be performed for specific routes or portions of routes. Different types of representation or levels of abstraction for the routing can be used for the same net or route. Partial topological reconfiguration, refinement, or rip-up can be performed for a portion of the integrated circuit design, where the portion is smaller than an entire route or net. Non-uniform levels of routing activities or resources may be applied to route the design. Prioritization may be used to route certain portions of the design with greater levels of detail, abstraction, or resources than other portions of the design.
Abstract: A circuit design process for the reduction of routing congestion is described. This process includes a block placement operation, an initial pin optimization for the block placement, and global routing based upon the initial pin optimization. Congestion data is generated from the global routing and, in an automated process, the pins are re-optimized, based upon the congestion data. This process can be used as part of a custom layout design process, for example.
Abstract: For an integrated circuit associated with a plurality of parameters whose values are described by a first probability distribution function, a method for estimating a failure probability includes selecting a first plurality of samples, performing a first test to determine an outcome for each of the first plurality of samples and identifying failed samples, and clustering the failed samples using a computer-implemented cluster forming method that, in some cases, returns multiple clusters. The method also includes forming a probability distribution function for each of the clusters, forming a composite probability distribution function that includes a weighted combination of the first probability distribution function and the probability distribution function for each of the clusters. The method further includes selecting a second plurality of samples using the composite probability distribution function and performing a second test to determine an outcome for each of the second plurality of samples.
Abstract: For an integrated circuit associated with a first plurality of parameters whose values are described by a first probability distribution function, a method for estimating a failure probability includes selecting a first plurality of samples, performing a first test to determine an outcome for each of the first plurality of samples and identifying failed samples. A second plurality of parameters is selected that has fewer parameters than the first plurality of parameters. The failed samples are clustered in the space of the second plurality of parameters using a computer-implemented cluster forming method that, in some cases, returns multiple clusters. The method also includes forming a probability distribution function for each of the clusters, forming a composite probability distribution function that includes a weighted combination of the first probability distribution function and the probability distribution function for each of the clusters.
Abstract: Disclosed are method, system, and computer program product for a method and system for a fast and stable placement/floorplanning method that gives consistent and good quality results. Various embodiments of the present invention provide a method and system for approximate placement of various standard cells, macro-blocks, and I/O pads for the design of integrated circuits by approximating the final shapes of the objects of interest by one or more probability distribution functions over the areas for the objects of interest with improved runtime and very good stability. These probability distributions are gradually localized to final shapes satisfying the placement constraints and optimizing an objective function.
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.
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:
December 7, 2007
Date of Patent:
June 14, 2011
Assignee:
Cadence Design Systems, Inc.
Inventors:
Manish Pandey, Marcelo Glusman, Angela Krstic, Yee-Wing Hsieh, Andy Lin
Abstract: An electronic design is generated for an integrated circuit that is to be fabricated in accordance with the electronic design by a process that will impart topographically induced feature dimension variations to the integrated circuit. The generating includes adjusting the electronic design based on predictions of topographical and topographical-related feature dimension variations by a pattern-dependent model. An RC extraction tool is used in conjunction with the generating and adjusting of the electronic design. The process includes a fabrication process that will impart topographical variation to the integrated circuit and a lithography or etch process. Placement attributes for elements of the integrated circuit are determined.
Abstract: A federated system and methods and mechanisms of implementing and using such a system is disclosed. In some embodiments, one or more mappings are created between a taxonomy view at a node and one or more taxonomies of one or more data sources. The one or more data sources can then be accessed via the taxonomy view. In other embodiments, one or more mappings are created between content from different data sources and content from those data sources are merged using the one or more mappings.
Type:
Grant
Filed:
April 16, 2010
Date of Patent:
June 14, 2011
Assignee:
Cadence Design Systems, Inc.
Inventors:
Steven Sholtis, Terry LeClair, Kenneth Jerome Henderson
Abstract: Disclosed are an improved method, system, and computer program product for a method or system with concurrent models to more accurately determine and represent the three-dimensional design features of electronic designs. Some embodiments disclose a method or a system for determining the design feature characteristics based upon their respective three-dimensional profiles. Some other embodiments further determine whether the design objectives or constraints are met or may be relaxed based upon the design feature characteristics in order to complete the design. Other embodiments store the profile or geometric characteristics, or information derived therefrom, in a database associated with the design to reduce the need for potentially expensive computations. The method or system may modify the designs or the processes to reflect whether the design objectives or constraints are met or relaxed.