Abstract: A system for generating a layout of an integrated circuit is disclosed. The system includes at least one processing unit for executing computer programs, a graphical-user-interface for viewing representations of the integrated circuit on a display and observing the layout of the integrated circuit, and a memory for storing databases of the integrated circuit. The system further includes means for retrieving locations of a plurality of devices from a schematic of the integrated circuit, means for retrieving user-specified placement constraints, and means for placing the devices in accordance with the locations and the user-specified placement constraints.
Abstract: Disclosed is a method, system, and article of manufacture for a one-pass approach for implementing metal-fill for an integrated circuit. Also disclosed is a method, system, and article of manufacture for implementing metal-fill that is coupled to a tie-off connection. An approach that is disclosed comprises a method, system, and article of manufacture for implementing metal-fill having an elongated shape that corresponds to the length of whitespace. Also disclosed is the aspect of implementing metal-fill that matches the routing direction. Yet another disclosure is an implementation of a place & route tool incorporating an integrated metal-fill mechanism.
Type:
Grant
Filed:
November 19, 2002
Date of Patent:
February 5, 2008
Assignee:
Cadence Design Systems, Inc.
Inventors:
Thanh Vuong, William H. Kao, David C. Noice
Abstract: A method for building a hierarchical representation of a circuit for simulation includes 1) receiving a source file containing SPICE-like netlist descriptions of the circuit in a flattened representation; 2) generating a primitive database using the source file, where the primitive database includes a geometries-describing section for storing a plurality of primitive subcircuit blocks; 3) generating an instance database using the geometries-describing section, where the instances database includes instance subcircuit blocks corresponding to explicitly-expressed primitive subcircuit blocks with predefined geometric values; 4) generating a simulation database using the instance database, where the simulation database includes simulation subcircuit blocks corresponding to fully-flattened instance subcircuit blocks; and 5) simulating the circuit using the simulation database, the instance database, and the primitive database.
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: The present invention presents methods for modeling the high frequency and noise characterization of MOSFETs. The models may be readily implemented as part of a SPICE or other simulation in a design flow. In particular, this invention is capable of providing a sub-circuit representation of a MOSFET that can accurately predicate a MOSFET's low frequency, high frequency, and noise characterizations. An interface is described through which a user may simultaneously optimize all of these characterizations. Further, methods are presented for building models that can predicate the variations in MOSFETs due to manufacturing processes and generate a corresponding corner model.
Abstract: A system, method, and computer program accurately models circuit parameter variation for delay calculation. For any given circuit parameter value, a cell is characterized at just three values in the circuit parameter range. An interpolation process generates an equation to calculate delay using the characterization data from the three circuit parameter values. This delay equation calculates the delay for any value in the circuit parameter range. Similar methodology is used to model simultaneous variation of two circuit parameters. The cell is characterized at just six circuit parameter pairs to interpolate the delay equation for any circuit parameter pair in the characterized ranges. This methodology can be extended to accommodate variation of multiple circuit parameters using similar interpolation techniques.
Abstract: System and method is disclosed for breaking an integrated circuit design to be printed into two or more exposures by lithographic equipment, each of the two or more exposures has at least the minimum pitch. Together, these multiple exposures print an integrated circuit design that could not be printed in one exposure alone.
Abstract: Some embodiments of the invention provide vias that are not in shape of quadrilaterals. In some embodiments, some or all vias are in shape of non-quadrilateral polygons, such as octagons and hexagons. In some embodiments, some or all vias have a circular shape. Some embodiments provide a first set of vias that have a diamond shape and a second set of vias that have a rectangular shape. In some embodiments, a via can also be formed by a diamond contact and a rectangular contact. The diamond contact has four sides. In the embodiments described below, all four sides of a diamond via contact have equal sides. However, in other embodiments, a via contact can be in shape of a diamond with a pair of sides that are longer than the other pair of sides. Similarly, in the embodiments described below, the rectangular via contacts are squares with four equal sides. However, in other embodiments, the length and width of a rectangular via contact can differ.
Abstract: Disclosed is an improved approach for organizing, analyzing, and operating upon polygon data which significantly reduces the amount of data required for processing while keeping elements non-interfacing with each other. According to one approach, clusters of elements are extracted which are then handled separately. In some approaches, a set of polygons forms a cluster if for any two polygons from the set of polygons there exists a sequence of polygons from the set such that the distance between any sequential polygons are less than or equal to a given threshold number. Rather than analyzing each and every polygon in the design, repetitive unique patterns are analyzed once, which are then replicated for all clusters which have the same repetitive pattern.
Type:
Application
Filed:
January 17, 2007
Publication date:
December 13, 2007
Applicant:
Cadence Design System, Inc.
Inventors:
Anwar Irmatov, Alexander Belousov, Eitan Cadouri, Andrei Gratchev, Alexander Ryjov, Laurent Thenie
Abstract: A method and an apparatus to improve hierarchical design implementation have been disclosed. In one embodiment, the method includes deriving boundary logic of at least one of a plurality of partitions in an integrated circuit (IC) design, marking the boundary logic of the at least one of the plurality of partitions based on at least one predetermined criterion, and performing implementation of the IC design using the marked boundary logic.
Abstract: A method, apparatus and method for compiling a hardware design for performing hardware emulation using synchronized processors is described. The apparatus comprises a plurality of processors defining a processor group for evaluating data regarding a hardware design and a synchronizer for synchronizing the operation of the processor group while emulating at least a portion of the hardware design. The method comprises providing a synchronization signal to a plurality of processors defining a processor group for evaluating data regarding a hardware design, receiving a ready signal from the processor group, and providing an execution signal to the processor group, where the execution signal causes the processor group to evaluate a submodel. The method for compiling the hardware design comprises converting at least one high-level construct into a sequence of operations and identifying a sequence of operations that comprise at least one conditional submodel.
Type:
Application
Filed:
May 31, 2006
Publication date:
December 6, 2007
Applicant:
Cadence Design Systems, Inc.
Inventors:
Mikhail Bershteyn, Charles Berghorn, Mitchell G. Poplack
Abstract: A method for generating lithography masks includes generating integrated circuit design data and using context information from the integrated circuit design data to write a mask.
Abstract: A system and method which allows for burst licensing, particularly for use in a circuit design and analysis system in which designers use tools to assist in characterizing and verifying the circuit. Burst licensing is used to provide licenses on an ‘as and when required’ basis to allow system users or customers to carry out massive parallelism of the simulation tasks when run from selected tools. When the system receives a request to start a task, the system checks-out a burst license for use in processing the task, and assigns the license to a particular CPU. The task is then performed at that CPU, and once completed the burst license is returned to the license pool.
Type:
Grant
Filed:
December 2, 2004
Date of Patent:
November 20, 2007
Assignee:
Cadence Design Systems, Inc.
Inventors:
Paul C. Foster, James Britton, Alan Mayes, Richard E. Seiter
Abstract: The present invention includes a method for detecting model stamping errors during circuit simulation without the need for golden data. The method checks for model stamping errors by determining whether entries in model stamping matrices interrelate according to a plurality of preset rules before circuit equations are solved.
Abstract: Workspace definitions, which define an execution environment, can be associated with jobs. A work request is processed to automatically determine that tasks that are progeny of a given job inherit the association with the workspace definition, and therefore, that the tasks should be executed using the execution environment defined in the workspace definition. However, different execution environments can be defined for progeny of a given parent job, essentially overriding the inheritance from the parent job. According to an embodiment, a set of resources associated with an execution environment is configured such that the resources are accessible by two or more computers of a group of networked computers, such as a server farm, without requiring configuring duplicate sets of the resources. Furthermore, in a server farm computing environment, an execution environment associated with one or more jobs is not reliant on being created on any given computer of the server farm.
Abstract: The present invention provides a process for constrained clock skew scheduling which computes for a given number of clocking domains the optimal phase shifts for the domains and the assignment of the individual registers to the domains. For the within domain latency values, the algorithm can assume a zero-skew clock delivery or apply a user-provided upper bound. Experiments have demonstrated that a constrained clock skew schedule using a few clocking domains combined with small within-domain latency can reliably implement the full sequential optimization potential to date only possible with an unconstrained clock schedule.
Type:
Grant
Filed:
November 5, 2003
Date of Patent:
November 13, 2007
Assignee:
Cadence Design Systems, Inc.
Inventors:
Andreas Kuehlmann, Kaushik Ravindran, Ellen Sentovich
Abstract: A method for encoding elements of an electronic design generates a flattened hierarchy of a parameterized cell of the electronic design, selects common and unique parameters of each element in the parameterized cell, and generates a physical design quantization characteristic value from the selected common and unique parameters.
Abstract: The present invention is directed to a number of improvements in methods for reliability simulations in aged circuits whose operation has been degraded through hot-carrier or other effects. A plurality of different circuit stress times can be simulated within a single run. Different aging criteria may be used for different circuit blocks, circuit block types, devices, device models and device types. The user may specify the degradation of selected circuit blocks, circuit block types, devices, device models and device types independently of the simulation. Device degradation can be characterized in tables. Continuous degradation levels can be quantized. Techniques are also described for representing the aged device in the netlist as the fresh device augmented with a plurality of independent current sources connected between its terminals to mimic the effects of aging in the device. The use of device model cards with age parameters is also described.
Type:
Grant
Filed:
April 11, 2001
Date of Patent:
November 6, 2007
Assignee:
Cadence Design Systems, Inc.
Inventors:
Lifeng Wu, Zhihong Liu, Alvin I. Chen, Jeong Y. Choi, Bruce W. McGaughy
Abstract: Disclosed is a method, system, and article of manufacture for a one-pass approach for implementing metal-fill for an integrated circuit. Also disclosed is a method, system, and article of manufacture for implementing metal-fill that is coupled to a tie-off connection. An approach that is disclosed comprises a method, system, and article of manufacture for implementing metal-fill having an elongated shape that corresponds to the length of whitespace. Also disclosed is the aspect of implementing metal-fill that matches the routing direction. Yet another disclosure is an implementation of a place & route tool incorporating an integrated metal-fill mechanism.
Type:
Grant
Filed:
November 19, 2002
Date of Patent:
October 30, 2007
Assignee:
Cadence Design Systems, Inc.
Inventors:
Thanh Vuong, William H. Kao, David C. Noice
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.