Abstract: An apparatus and method of synthesizing a photolithographic data set includes using a first computational model to calculate a first figure-of-merit for the photolithographic data set; changing a first part of the photolithographic data set to increase the first figure-of-merit; and then using a second computational model to calculate a second figure-of-merit of the photolithographic data set; and changing a second part of the photolithographic data set to increase the second figure-of-merit. The second computational model enables figure-of-merit calculations to be executed at a significantly faster execution rate than the first computational model.
Type:
Grant
Filed:
August 13, 2005
Date of Patent:
June 22, 2010
Assignee:
Cadence Design Systems, Inc.
Inventors:
Abdurrahman Sezginer, Roy Prasad, Chi-Song Horng, Hsu-Ting Huang
Abstract: A method is provided that includes: determining a minimum clock cycle that can be used to propagate a signal about the critical cycle in a circuit design; wherein the critical cycle is a cycle in the design that has a highest proportionality of delay to number of registers; determining for a circuit element in the circuit design, sequential slack associated with the circuit element; wherein the sequential slack represents a minimum delay from among respective maximum delays that can be added to respective structural cycles of which the circuit element is a constituent, based upon the determined limit upon clock cycle duration; using the sequential slack to ascertain sequential optimization based design flexibility throughout multiple stages of a design flow.
Type:
Grant
Filed:
May 2, 2007
Date of Patent:
June 22, 2010
Assignee:
Cadence Design Systems, Inc.
Inventors:
Christoph Albrecht, Philip Chong, Andreas Kuehlmann, Ellen Sentovich, Roberto Passerone
Abstract: A method of adding power control circuitry to a circuit design at each of an RTL and a netlist level comprising: demarcating multiple power domains within the circuit design; specifying multiple power modes each power mode corresponding to a different combination of on/off states of the multiple demarcated power domains; and defining isolation behavior relative to respective power domains.
Type:
Grant
Filed:
October 30, 2006
Date of Patent:
June 15, 2010
Assignee:
Cadence Design Systems, Inc.
Inventors:
Qi Wang, Ankur Gupta, Pinhong Chen, Christina Chu, Manish Pandey, Huan-Chih Tsai, Sandeep Bhatia, Yonghao Chen, Steven Sharp, Vivek Chickermane, Patrick Gallagher
Abstract: A method is provided that includes: determining a minimum clock cycle that can be used to propagate a signal about the critical cycle in a circuit design; wherein the critical cycle is a cycle in the design that has a highest proportionality of delay to number of registers; determining for a circuit element in the circuit design, sequential slack associated with the circuit element; wherein the sequential slack represents a minimum delay from among respective maximum delays that can be added to respective structural cycles of which the circuit element is a constituent, based upon the determined limit upon clock cycle duration; using the sequential slack to ascertain sequential optimization based design flexibility throughout multiple stages of a design flow.
Abstract: A method and apparatus for designing a processor-based emulation integrated circuit (chip) having a selectable fastpath topology. Included are initially designing an N-level fastpath topology comprising a plurality of processors, then reducing the N-level fastpath topology to an M-level topology such that the performance of the topology meets a design criterion, e.g., capable of evaluating data during a time of an emulation step. In this manner, an emulator chip designer may configure the fastpath topologies without redesigning the chip layout.
Abstract: In one embodiment of the invention, an integrated circuit (IC) design tool is provided that has a sum-of-products (SOP) synthesizer. The SOP synthesizer receives expected arrival times of signals including partial product terms of each bit-vector of a SOP functional block, a comparison gate delay, and a register-transfer-level (RTL) netlist in order to synthesize a gate-level netlist of the SOP functional block. The SOP synthesizer includes software modules to synthesize a partial products generator, a partial product reduction tree, and an adder. The synthesis of the partial product reduction tree is responsive to a comparison gate delay and the expected arrival times of the partial product terms in each bit vector.
Abstract: A computer-implemented method of identifying sub-circuits in circuit designs includes: receiving a selection of a sub-circuit; specifying a match expression for the sub-circuit, where the match expression characterizes matching properties of components of the sub-circuit; modifying the match expression to change the matching properties of components of the sub-circuit; and producing an information structure in a computer readable medium, where the information structure associates a graph representing a topology of the selected sub-circuit with the modified match expression. Subsequently, the information structure corresponding to the selected sub-circuit can be identified in a given circuit design.
Type:
Grant
Filed:
May 8, 2007
Date of Patent:
June 8, 2010
Assignee:
Cadence Design Systems, Inc.
Inventors:
Ian Campbell Dennison, Mark Baker, Bogdan Arsintescu, Donald John O'Riordan
Abstract: A system, method, computer program product for verification and equivalence checking. In one approach, the system, method, and computer program product analyzes the switching paths in a manner consistent with circuit functionality to provide a complete application which can verify the complex characteristics in the circuits to the accurate RTL model function, including FPGA, ROM Arrays, RAM circuits, and other custom integrated circuit designs.
Type:
Grant
Filed:
May 31, 2006
Date of Patent:
June 8, 2010
Assignee:
Cadence Design Systems, Inc.
Inventors:
Kei-Yong Khoo, Mitchell Hines, Chih-Chang Lin
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 method of simulating a restorable register in a power domain of an RTL (register transfer level) design includes: specifying the power domain in the RTL design, wherein the power domain includes one or more registers and is configured to change power levels separately from other portions of the RTL design; identifying the restorable register in the power domain, wherein the restorable register is updated during power-on operations in the power domain; simulating the restorable register in a power cycle; and saving one or more values from the simulated restorable register. Simulating the restorable register includes: maintaining one or more backup values during a power-off operation for updating the restorable register after the power-off operation; and updating the restorable register during a power-on operation after the power-off operation by using the one or more backup values.
Type:
Grant
Filed:
June 29, 2007
Date of Patent:
June 8, 2010
Assignee:
Cadence Design Systems, Inc.
Inventors:
Nadeem Kalil, Philip Giangarra, Ritesh Goel, Tarun Batra
Abstract: Methods achieve fast parasitic closure in IC (integrated circuit) synthesis flow with particular application to RFIC (radio frequency integrated circuit) synthesis flow. Parasitic corners generated based on earlier layout statistics are incorporated into circuit resizing to enable parasitic robust designs. The worst-case parasitic corners are generated efficiently without expensive statistical computations. A performance-driven placement with simultaneous fast rough routing and device tuning generates high quality placements and compensates for layout induced performance degradations. A regression-tree based macromodeling methodology is introduced for modeling of electrical performances to enable true performance-driven layout synthesis. To improve sampling quality, an annealing-based placer can be used to perform sampling. The modeling methodology can be adapted to include automatically adjusting the device tuning ranges to meet certain model accuracy requirements.
Type:
Grant
Filed:
November 24, 2004
Date of Patent:
June 8, 2010
Assignee:
Cadence Design Systems, Inc.
Inventors:
Gang Zhang, Enis Aykut Dengi, Ronald A. Rohrer
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 11, 2006
Date of Patent:
June 1, 2010
Assignee:
Cadence Design Systems, Inc.
Inventors:
Steven Teig, Raghu Chalasani, Akira Fujimura
Abstract: A method and apparatus for coupling data between discrete processor-based emulation chips is described. The apparatus is a processor-based hardware emulation integrated circuits (chips) element comprising a plurality of discrete hardware emulation chips, each emulation chip coupled to another emulation chip by a crossbar for coupling data between the plurality of chips. The method comprises providing data to a crossbar from a first discrete emulation chip, selecting the data from the crossbar using a discrete second emulation chip, and storing the data in a data array in the second discrete emulation chip.
Type:
Grant
Filed:
May 22, 2006
Date of Patent:
May 25, 2010
Assignee:
Cadence Design Systems, Inc.
Inventors:
William F. Beausoleil, Beshara G. Elmufdi
Abstract: Method and system for chip optimization using model based verification (MBV) tool provide more accurate verification in determining hotspots and their characteristics. The MBV and the layout optimizer are implemented within a feedback loop. This type of verification allows for the MBV tool to provide hints, constraints and hotspot information to the layout optimizer. In addition, the model-based simulation results can be used to automatically fix the circuit designs and allow for specialized optimization flow for standard cell libraries.
Type:
Grant
Filed:
February 24, 2007
Date of Patent:
May 25, 2010
Assignee:
Cadence Design Systems, Inc.
Inventors:
David White, Roland Ruehl, Eric Nequist
Abstract: A method for implementing virtual metal fill includes obtaining a layout record for a circuit design, and inserting metal fill data into the layout record based on one or more rules, wherein the metal fill data represents a consolidation of actual metal fill. A method for implementing virtual metal fill includes obtaining a layout record for a circuit design, and inserting metal fill data into the layout record, the metal fill data representing a virtual metal fill having a configuration that is different from a configuration of actual metal fill.
Type:
Grant
Filed:
July 30, 2004
Date of Patent:
May 25, 2010
Assignee:
Cadence Design Systems, Inc.
Inventors:
Terrence A. Lenahan, Kuang-Wei Chiang, Jue Wang
Abstract: Disclosed is a method, system, and computer program product for timing closure with concurrent models for fabrication, metrology, lithography, and/or imaging processing analyses for electronic designs. Some embodiments of the present invention disclose a method for timing closure with concurrent process model analysis which comprises the act of generating a design for the one or more interconnect levels; analyzing the effects of the concurrent models to predict feature dimension variations based upon the concurrent models; modifying the design files to reflect the variations; determining one or more parameters based upon the concurrent models; and determining the impact of concurrent models upon the electrical and timing performance. Some embodiments disclose a computerized system for implementing the method(s) disclosed herein. Some embodiments also disclosed a computer program product comprising executable code for the method(s) disclosed herein.
Abstract: Some embodiments of the invention provide a router that can define a route that has different widths along different directions on the same layer. To facilitate the creation of such a route, some embodiments adaptively define the shape of interconnect-line ends (i.e., the shape of route-segment ends) on a particular layer based on the routing directions available on the particular layer. By so defining these shapes, these embodiments improve the alignment of route segments that have differing widths. In other words, dynamically defining the interconnect-line ends improves the shape of a route at bends along which the route transition from one width to another. Also, to facilitate the creation of a route with different widths and/or spacing in different directions on a particular layer, some embodiments define, for each available routing direction on the particular layer, an “unroutable” bloated region about a previously defined geometry (e.g.
Abstract: A system for controlling reset in discrete event simulation is disclosed. The system includes a simulator configured to effect the discrete event simulation, the simulator having a plurality of shared executable files, a memory configured to store the simulator for execution, an operating system having a loading/unloading facility, and a control program configured to effect a reset operation by directing the operating system to unload the simulator from the memory and then reload the simulator into the memory using the loading/unloading facility.
Type:
Grant
Filed:
May 4, 2006
Date of Patent:
May 18, 2010
Assignee:
Cadence Design Systems, Inc.
Inventors:
George Franklin Frazier, Qizhang Chao, Tuay-Ling Kathy Lang, Neeti Khullar Bhatnagar, Andrew Robert Wilmot
Abstract: Disclosed is a method, system, and computer program product for performing edge optimization on an electronic design. According to some approaches, the number of edges and/or the length of edges within an IC design are configured for optimized manufacturability and yield of an integrated circuit. The edge optimization may occur in real-time during layout, placement, and/or routing, or occur in a post-optimization step.
Abstract: A method and system of improving signal integrity in integrated circuit designs is disclosed. In some embodiments, signal integrity optimization is conducted in conjunction with detailed routing of an integrated circuit design based upon a global routing plan previously generated for the design.
Type:
Grant
Filed:
May 13, 2005
Date of Patent:
May 11, 2010
Assignee:
Cadence Design Systems, Inc.
Inventors:
Ying-Meng Li, Chih-Wei Chang, Louis Chao, So Zen Yao