Patents Represented by Attorney Alford Law Group, Inc.
  • Patent number: 8341572
    Abstract: A system and method are disclosed for waveform based variational static timing analysis. A circuit is divided into its linear circuit parts and non-linear circuit parts and modeled together, by a combination of linear modeling techniques, into linear equations that may be represented by matrices. The linear equations in matrix form may be readily solved by a computer such that an input waveform to an input pin of the circuit can be sequentially “pushed” through the various interconnects and logic networks of the circuit to an output pin. Output voltage waveforms are obtained at each stage of the waveform pushing and may be used to perform static timing analysis.
    Type: Grant
    Filed: December 9, 2008
    Date of Patent: December 25, 2012
    Assignee: Cadence Design Systems, Inc.
    Inventors: Saurabh K. Tiwary, Joel R. Phillips, Igor Keller
  • Patent number: 8341300
    Abstract: In one embodiment of the invention, a memory system includes non-volatile-memory-devices (NVMDs) coupled to memory channels to share busses and a memory controller coupled to the memory channels in communication between the plurality of NVMDs. Each NVMD independently executes a read, write, or erase operation at a time. The memory controller includes channel schedulers to schedule control and data transfers associated with the read, write, and erase operations on the memory channels; and high priority and low priority queues coupled to the channel schedulers. The channel schedulers prioritize operations waiting in the high priority queues over operations waiting in the low priority queues. The channel schedulers further prioritize read operations waiting in either the high priority queue or the low priority queue over write and erase operations waiting in each respective queue.
    Type: Grant
    Filed: June 16, 2011
    Date of Patent: December 25, 2012
    Assignee: Virident Systems, Inc.
    Inventors: Vijay Karamcheti, Shibabrata Mondal, Ajith Kumar
  • Patent number: 8336010
    Abstract: In one embodiment of the invention, a method of analysis of a circuit design with respect to within-die process variation is disclosed to generate a design-specific on chip variation (DS-OCV) de-rating factor. The method includes executing a static timing analysis (STA) in an on-chip variation mode using a process corner library. Collecting timing information of the top N critical timing paths. Executing a statistical static timing analysis (SSTA) on the N critical timing paths using timing models characterized for SSTA with sensitivities of delays to process variables. Compare the two timing results and deriving DS-OCV de-rating factors for the clock/data paths to be used in a STA OCV timing analysis to correctly account for the effects of process variations. A user may select to specify DS-OCV de-rating factors for paths or groups of paths and achieve an accurate timing analysis report in a reduced amount of run-time.
    Type: Grant
    Filed: June 27, 2010
    Date of Patent: December 18, 2012
    Assignee: Cadence Design Systems, Inc.
    Inventors: Hongliang Chang, Vassilios Gerousis, Sireesha Molakalapalli, Sachin Shrivastava
  • Patent number: 8326591
    Abstract: In one embodiment of the invention, a method of simulating a circuit is disclosed including partitioning a circuit into a plurality of blocks, each of the plurality of blocks being radio-frequency blocks or non-radio frequency blocks; performing a first simulation of a first simulation type with the radio-frequency blocks to generate output waveforms of the radio-frequency blocks; performing a second simulation of a second simulation type with the non-radio-frequency blocks to generate output waveforms of the non-radio-frequency blocks where the second simulation type differs from the first simulation type; and synchronizing the first simulation and the second simulation together at one or more time steps to generate output waveforms for the circuit.
    Type: Grant
    Filed: November 16, 2007
    Date of Patent: December 4, 2012
    Assignee: Cadence Design Systems, Inc.
    Inventors: Qian Cai, Dan Feng, Bruce W. McGaughy, Jun Kong, Rendong Lin
  • Patent number: 8302046
    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.
    Type: Grant
    Filed: November 11, 2008
    Date of Patent: October 30, 2012
    Assignee: Cadence Design Systems, Inc.
    Inventors: Igor Keller, King Ho Tam
  • Patent number: 8291365
    Abstract: An innovative routing method for an integrated circuit design layout. The layout can include design netlists and library cells. A multiple-level global routing can generate topological wire for each net. An area oriented graph-based detail routing on the design can be performed. A post route optimization after the detail routing can be performed to further improve the routing quality. Some methods can be single threaded all or some of the time, and/or multi-threaded some or all of the time.
    Type: Grant
    Filed: January 6, 2006
    Date of Patent: October 16, 2012
    Assignee: Cadence Design Systems, Inc.
    Inventors: Limin He, So-Zen Yao, Wenyong Deng, Jing Chen, Liang-Jih Chao
  • Patent number: 8255857
    Abstract: Routing methods for an integrated circuit design layout are disclosed. The layout can include design netlists and library cells. A multiple-level global routing can generate topological wire for each net. An area oriented graph-based detail routing on the design can be performed. A post route optimization after the detail routing can be performed to further improve the routing quality. Some methods can be single threaded all or some of the time, and/or multi-threaded some or all of the time.
    Type: Grant
    Filed: December 31, 2008
    Date of Patent: August 28, 2012
    Assignee: Cadence Design Systems, Inc.
    Inventors: Limin He, So-Zen Yao, Wenyong Deng, Jing Chen, Liang-Jih Chao
  • Patent number: 8245167
    Abstract: In one embodiment of the invention, a method for electronic circuit design is disclosed.
    Type: Grant
    Filed: February 14, 2009
    Date of Patent: August 14, 2012
    Assignee: Cadence Design Systems, Inc.
    Inventors: Luis Guerra e Silva, Luis Miguel Silveira, Joel Phillips
  • Patent number: 8245165
    Abstract: A system and method are disclosed for waveform based variational static timing analysis. A circuit is divided into its linear circuit parts and non-linear circuit parts and modeled together, by a combination of linear modeling techniques, into linear equations that may be represented by matrices. The linear equations in matrix form may be readily solved by a computer such that an input waveform to an input pin of the circuit can be sequentially “pushed” through the various interconnects and logic networks of the circuit to an output pin. Output voltage waveforms are obtained at each stage of the waveform pushing and may be used to perform static timing analysis.
    Type: Grant
    Filed: December 9, 2008
    Date of Patent: August 14, 2012
    Assignee: Cadence Design Systems, Inc.
    Inventors: Saurabh K. Tiwary, Joel R. Phillips, Igor Keller
  • Patent number: 8239798
    Abstract: In one embodiment of the invention, a method of analysis of a circuit design is disclosed to generate a statistical timing model. The method includes receiving a timing graph of a circuit including arcs with a statistical function of delay, slew, or arrival time; determining primary input ports and output ports of the circuit; identifying timing pins between the input ports and the output ports of the circuit; and evaluating the timing pins from input ports to output ports to reduce the timing graph to ease analysis of the reduced timing graph with a processor.
    Type: Grant
    Filed: August 2, 2008
    Date of Patent: August 7, 2012
    Assignee: Cadence Design Systems, Inc.
    Inventors: Ratnakar Goyal, Naresh Kumar, Harindranath Parmeswaran
  • Patent number: 8225006
    Abstract: In one embodiment of the invention, a method for data redundancy across three or more storage devices is disclosed. The method includes storing a collection of data chunks as a plurality of N-1 data stripes across N storage devices where N is three or more, wherein each data chunk of up to N data chunks forming a data stripe is stored in a different storage device; storing a parity stripe across the N storage devices including N-1 data parity chunks and one meta data parity chunk; wherein each Kth storage device of N-1 storage devices stores a Kth data parity chunk of the N-1 data parity chunks computed as parity of up to N data chunks forming the Kth data stripe; and wherein an Nth storage device of the N storage devices stores the meta parity chunk computed as parity of the N-1 data parity chunks stored in the respective N-1 storage devices.
    Type: Grant
    Filed: June 17, 2011
    Date of Patent: July 17, 2012
    Assignee: Virident Systems, Inc.
    Inventor: Vijay Karamcheti
  • Patent number: 8214782
    Abstract: In some embodiments of the invention, a method and apparatus of consolidating all types of coverage metrics, obtained from an HDL simulator, under a single common framework is described. In other embodiments of the invention, a method and an apparatus are disclosed for performing ranking from a verification plan using total coverage metric.
    Type: Grant
    Filed: January 26, 2011
    Date of Patent: July 3, 2012
    Assignee: Cadence Design Systems, Inc.
    Inventors: Swapnajit Chakraborti, Sandeep Pagey, Boris Gommershtadt, Yael Duek-Golan
  • Patent number: 8209647
    Abstract: An extensible design verification system and methods thereof are disclosed. Pre-defined constraints from an integrated verification application are registered with a core which manages the verification system. The core is utilized by the integrated verification application to execute one or more verification tasks to generate a result. The result can be captured by a user interface. Constraints and the user-interface can be either pre-defined or user-defined. User-defined constraints and interface are managed in the same manner as those that are pre-defined. The user-defined constraints and interface are exportable for reuse by other designs.
    Type: Grant
    Filed: February 20, 2008
    Date of Patent: June 26, 2012
    Assignee: Cadence Design Systems, Inc.
    Inventor: Robert Roesler
  • Patent number: 8205182
    Abstract: In one embodiment of the invention, a method for designing an integrated circuit is disclosed. The method includes automatically partitioning clock sinks of an integrated circuit design into a plurality of partitions; automatically synthesizing a clock tree from a master clock generator into the plurality of partitions to minimize local clock skew within each of the plurality of partitions; and automatically synthesizing clock de-skew circuitry into each of the plurality of partitions to control clock skew between neighboring partitions.
    Type: Grant
    Filed: August 22, 2008
    Date of Patent: June 19, 2012
    Assignee: Cadence Design Systems, Inc.
    Inventors: Radu Zlatanovici, Christoph Albrecht, Saurabh Kumar Tiwary
  • Patent number: 8201121
    Abstract: In one embodiment of the invention, a method of designing integrated circuits is disclosed. The method includes determining a power correction factor for a subset of partitions of circuits in an integrated circuit design; determining a gross power consumption estimate for all partitions of circuits in the integrated circuit design without synthesizing the entire integrated circuit design; and improving the accuracy of the gross power consumption estimate using the power correction factor to generate a reasonably accurate power consumption estimate for the entire integrated circuit design prior to substantially full circuit synthesis thereof.
    Type: Grant
    Filed: May 28, 2008
    Date of Patent: June 12, 2012
    Assignee: Cadence Design Systems, Inc.
    Inventors: Ranganathan P. Sankaralingam, Yan Meng
  • Patent number: 8189328
    Abstract: In one embodiment of the invention, a flash memory dual inline memory module (FMDIMM) is disclosed. The FMDIMM includes a printed circuit board (PCB) with an edge connector; a first plurality of multi-chip packaged flash memory/support application specific integrated circuit (ASIC) parts mounted to the printed circuit board and electrically coupled to the edge connector; and a first address device mounted to the PCB and electrically coupled to the edge connector and the first plurality of multi-chip packaged flash memory/support ASIC parts. Each of the first plurality of multi-chip packaged flash memory/support ASIC parts includes one or more randomly accessible flash memory die to periodically store data in a non-volatile manner.
    Type: Grant
    Filed: October 22, 2007
    Date of Patent: May 29, 2012
    Assignee: Virident Systems, Inc.
    Inventors: Ruban Kanapathippillai, Kenneth Alan Okin
  • Patent number: 8151229
    Abstract: A system and method for determining the criticality of each timing pin in a circuit design are disclosed. The criticality of a timing pin is the probability that the timing pin is on the path with the worst slack in the circuit design. According to the methodology, the slack for each timing pin is calculated, wherein each slack is a function of a process random variable. Then, the criticality of each timing pin is determined as the probability of the timing pin having the minimum slack among the slacks in an independent critical set of timing pins. The criticality of each timing pin may then be normalized. By determining the criticalities of the timing pins in a circuit design, a circuit design system may be able to more easily identify portions of the circuit design that need modification for timing and other purposes.
    Type: Grant
    Filed: April 10, 2007
    Date of Patent: April 3, 2012
    Assignee: Cadence Design Systems, Inc.
    Inventors: Hongliang Chang, Oleg Levitsky, Nikolay Rubanov, Vassilios Gerousis
  • Patent number: 8144160
    Abstract: Modification to frame buffer memory information associated with a first display may be used to update information displayed on a second display. The first display may be mapped to a matrix of display areas. The modification to the frame buffer memory information may be detected be detecting write memory address. One or more display areas affected by the modification to the frame buffer memory information may be identified based on display parameters associated with the first display. Frame buffer memory information associated with the one or more affected display areas may be retrieved and compressed before being transmitted over a communication link to be displayed on the second display.
    Type: Grant
    Filed: February 14, 2008
    Date of Patent: March 27, 2012
    Assignee: Emulex Corporation
    Inventors: Dwarka Partani, Sujith Arramreddy, Balakrishna Jayadev
  • Patent number: 8127260
    Abstract: In one embodiment of the invention, a physical layout wire-load algorithm is used to generate a wire-load model based on physical data including aspect ratio and wire definitions defined in a physical library. The physical layout estimator is utilized to dynamically produce the physical layout wire-load model and to calculate net length and delay for each optimization iteration.
    Type: Grant
    Filed: December 1, 2006
    Date of Patent: February 28, 2012
    Assignee: Cadence Design Systems, Inc.
    Inventors: Hurley Song, Denis Baylor, Matthew Robert Rardon
  • Patent number: D665584
    Type: Grant
    Filed: March 5, 2010
    Date of Patent: August 21, 2012
    Assignee: ORAFOL Europe GmbH
    Inventors: David Reed, John Nelson