Abstract: The present invention introduces methods, systems, and architectures for routing clock signals in an integrated circuit layout. The introduced clock signal clock signal structures are rendered with non Manhattan routing. In a first embodiment, the traditional recursive H clock signal structure is rendered after transforming the coordinates system such that a rotated recursive H clock signal structure is rendered. In another embodiment, a recursive Y structure is used to create a clock signal structure. The recursive Y structure may also be implemented in a rotated alignment. For clock signal redundancy, non Manhattan wiring may be used to create a clock signal mesh network.
Type:
Grant
Filed:
October 10, 2003
Date of Patent:
October 3, 2006
Assignee:
Cadence Design Systems, Inc.
Inventors:
Steven Teig, Raghu Chalasani, Akira Fujimura
Abstract: A system, method, computer program and article of manufacture for channel analysis. Channel analysis is a multi gigahertz capacity time domain circuit simulation which uses the impulse response of the channel to determine optimum filter settings and to produce wave form plots in a fraction of the time of circuit simulation.
Abstract: Some embodiments of the invention provide a method of decomposing a design layout. The method decomposes the layout into a tessellated graph with several edges. It then computes the capacity of the edges based on a interconnect line model that is used to connect elements in the design layout. The layout has two orthogonal coordinate axes. At least one interconnect line specified by the model is neither parallel nor perpendicular to the coordinate axes. Also, in some embodiments, some of the edges are neither parallel nor perpendicular to the coordinate axes.
Abstract: The present invention introduces novel methods of performing integrated circuit layout extraction. In the system of the present invention, complex resistance extraction problem is first broken down into a set of smaller extraction sub problems. Some of the smaller extraction sub problems may be handled by simple parametric models. For example, extracting the resistance from a straight section of interconnect wire may be performed by multiplying a known resistance per unit length by the length of the straight section of interconnect wire. For more complex resistance extraction sub problems, machine learning is used to build models.
Abstract: One embodiment of the invention is a method of specifying routes for a group of nets. The method identifies different routing solutions for the group of nets. It then selects the best routing solution.
Abstract: Disclosed are methods and systems for formulating a wirelength estimate that takes into account whether any of the routing directions are unavailable. Under certain circumstances, one or more of the routing layers may not be available for routing a wire. If this occurs, then the bounding box that is determined for performing the wirelength estimate would take into account the unavailability of the layer.
Type:
Grant
Filed:
December 29, 2004
Date of Patent:
September 12, 2006
Assignee:
Cadence Design Systems, Inc.
Inventors:
Hussein Etawil, Krishna Belkhale, Lu Sha, Jonathan Frankle
Abstract: A system for using machine learning based upon Bayesian inference using a hybrid Monte Carlo method to create a model for performing integrated circuit layout extraction is disclosed. The system of the present invention has two main phases: model creation and model application. The model creation phase comprises creating one or more extraction models using machine-learning techniques. First, a complex extraction problem is decomposed into smaller simpler extraction problems. Then, each smaller extraction problem is then analyzed to identify a set of physical parameters that fully define the smaller extraction problem. Then, for each of the smaller simpler extraction problems, complex mathematical models are created using machine learning techniques.
Abstract: A method and system for reducing test data volume in the testing of logic products such as integrated circuit chips. Test data loaded by a tester into the logic product to apply to portions of combinational logic circuitry therein in order to detect faults comprises “care” bits and “non-care” bits. The care bits target focal faults of interest in the logic circuitry being tested while the non-care bits do not. According to the invention, non-care bits in the test vector data are filled with repetitive background data to provide for a high degree of compressibility of the test vector data. A substantial portion of the care bits may also be set to a repetitive value and the original values later recovered.
Type:
Grant
Filed:
January 23, 2001
Date of Patent:
September 5, 2006
Assignee:
Cadence Design Systems, Inc.
Inventors:
Frank O. Distler, Leonard O. Farnsworth, III, Andrew Ferko, Brion L. Keller, Bernd K. Koenemann, Donald L. Wheater
Abstract: One embodiment of the invention is a recursive partitioning method that places circuit elements in an IC layout. This method initially defines a number of partitioning lines that divide an IC region into several sub-regions (also called slots). For a net in the region, the method then identifies the set of sub-regions (i.e., the set of slots) that contain the circuit elements (e.g., the pins or circuit modules) of that net. The set of sub-regions for the net represents the net's configuration with respect to the defined partitioning lines. Next, the placement method identifies attribute or attributes of a connection graph that models the net's configuration with respect to the partitioning lines. The connection graph for each net provides a topology of interconnect lines that connect the slots that contain the net's circuit elements. According to some embodiments of the invention, the connection graph for each net can have edges that are completely or partially diagonal.
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.
Abstract: A method of analyzing a design of an electronic circuit includes tessellating the design into a grid of rectangles, selecting at least one rectangle as a first level parent rectangle, and generating a plurality of second level child rectangles based on the first level parent rectangle.
Abstract: A method of analyzing a design of an electronic circuit uses slices. The method includes generating one or more slices, each slice comprising a contiguous region of the design, and generating an set comprising one or more bins for each slice. A search for an object may be performed by determining a search area, and identifying slices containing at least a portion of the search area. For each identified slice, each object within the search area is associated with one of the bins of the set for the slice.
Type:
Grant
Filed:
January 14, 2003
Date of Patent:
August 29, 2006
Assignee:
Cadence Design Systems, Inc.
Inventors:
Eric Nequist, Jeffrey Scott Salowe, Steven Lee Pucci
Abstract: Systems and methods for designing integrated circuits and for creating and using androgynous interfaces between electronic components of integrated circuits are disclosed. One preferred method of designing an integrated circuit includes several steps. In one step, a foundation block for the integrated circuit is specified, including specifying the locations of multiple androgynous interfaces in the integrated circuit. In another step, one or more component blocks to comprise the integrated circuit are identified for use. In another step, the component blocks to form a layout of the integrated circuit are positioned in a manner that minimizes connection distances between functional blocks and between functional blocks and the androgynous interfaces. In another step, the androgynous interfaces are set to perform as targets (slaves) or initiators (masters) based on the layout.
Abstract: Disclosed is an improved approach for maintaining the structures for objects in a layout. A single type of structure is maintained that can be used to store or track a polygon of any shape, as long as the shape possesses a supported number of sides. The structure is capable of supporting irregular polygons or objects having angled edges. In one approach, the structure maintains information about each polygon as if that polygon is an octagon. Therefore, any polygon having eight or less orthogonal or diagonal sides can be supported using this structure.
Abstract: Some embodiments of the invention provide a method of routing nets in a multi-layer integrated-circuit (“IC”) layout. For a particular net, the method specifies widths for routing the particular net in different directions on the same layer. It then defines a particular route for the particular net, where the route has different widths in the different directions on the same layer.
Abstract: Some embodiments provide a method of routing nets within a region of an integrated-circuit (“IC”) layout. The method uses a first set of lines to partition the IC region into a plurality of sub-regions. In addition, the method uses a second set of lines to measure congestion of routes for the nets within the IC region. According to this method, at least some of the lines in the second set are different from the lines in the first set.
Abstract: A Wireless bridge conjoins two previously incompatible technologies within a single device to leverage the strengths of each. The Wireless bridge marries the Personal Area Network (PAN) technology of Bluetooth as described in Bluetooth Specification Version 1.0B with the Wireless Local Area Network (WLAN) technology described in the IEEE802.11a specification to provide a wireless system level solution for peripheral devices to provide Internet service interactions. The invention brings together in a single working device implementations of these technologies so they do not interfere or disrupt the operation of each other and instead provide a seamless transition of a Bluetooth connection to Wireless Local Area Network/Internet connection. From the Wireless Local Area Network perspective the inventive wireless bridge extension allows a Bluetooth-enabled device to roam from one Wireless Access Point (bridge) to the next without losing its back end connection.
Type:
Grant
Filed:
May 22, 2002
Date of Patent:
August 22, 2006
Assignee:
Cadence Design Systems, Inc
Inventors:
Vikram Vij, Carl A. Gerrard, Bin Li, Larry Gardner, Sivasankar Chander, Murthy Kunchakarra, Tim McCoy, Richard Swan
Abstract: A work request is processed and interpreted to automatically establish job data structures associated with jobs constituent to the work and data storage structures associated with tasks constituent to the work. Further, parent-child relationships between jobs, sub-jobs and tasks are automatically established based on interpreting the work request. Once tasks are executed, log information related thereto is stored in respective data storage structures, for access and rendering upon request. Each data storage structure stores log information pertaining only to a respective task. In an embodiment, in response to receiving a request to delete a particular job, the particular job and all of its progeny sub-jobs and tasks are deleted. The work request does not include explicit commands to establish the job data and data storage structures, nor to store the log information in the data storage structures.
Abstract: A method for determining component placement in a circuit includes forming a tree structure that defines the placement of each of a plurality of components associated with the tree structure on a first side, a second side or on both sides of a symmetry line, with at least one component tagged for symmetric placement on both sides of a symmetry line; performing at least one search of the tree structure to determine an initial placement of a subset of the components; and performing another search of the tree structure to determine a final placement of the subset of components whereupon at least a part of each component tagged for symmetric placement is positioned on each side of the symmetry line. The method can be embodied as instructions stored on a computer readable medium which, when executed by a processor, cause the processor to implement the method.
Abstract: Some embodiments of the invention provide a method of identifying a group of routes for a set of nets. The group of routes includes one route for each net in the set of nets. The method identifies a set of routes for each net. It then iteratively selects one identified route for each net. During each iteration, the method selects the identified route that least increases a tracking cost that accounts for each of the previously selected routes.