Patents Represented by Attorney Alford Law Group, Inc.
  • Patent number: 8095900
    Abstract: Achieving clock timing closure in designing an integrated circuit involves virtually synthesizing a clock network for the integrated circuit design to generate virtual clock buffering in the clock network before a point in the design flow at which the clock network is actually synthesized and committed to a netlist. Timing violations are determined for clock gates generated by the virtual clock buffering. Clock gating transforms are evaluated for the clock gates having the timing violations, based on recalculated clock and data path delays, to incrementally virtually synthesize the clock network. The clock gating transforms that result in the best timing gains are committed to the netlist. The clock network is then actually synthesized for the integrated circuit design, and design changes, due to the actual clock network synthesis, are committed to the netlist.
    Type: Grant
    Filed: September 16, 2008
    Date of Patent: January 10, 2012
    Assignee: Cadence Design Systems, Inc.
    Inventors: Sourav Kumar Sircar, Manish Baronia
  • Patent number: 8078925
    Abstract: In one embodiment of the invention, an apparatus for scan testing an integrated circuit is provided. The apparatus includes a combinational logic network; and a device for reducing gate switching in the combinational logic network to reduce power consumption during a scan test on the combinational logic network. The device for reducing gate switching in the combinational logic network includes a device for periodically isolating scan data from the combination logic network; and a device for periodically holding functional data coupled into the combinational network substantially steady. In one embodiment of the invention, the device for reducing gate switching in the combinational logic network is a plurality of serially coupled scan registers each having a pair of opposed controlled outputs with one controlled output providing scan output data and another controlled output providing functional data to the combinational logic network.
    Type: Grant
    Filed: May 11, 2010
    Date of Patent: December 13, 2011
    Assignee: Cadence Design Systems, Inc.
    Inventors: Sandeep Bhatia, Oriol Roig
  • Patent number: 8074022
    Abstract: A computer system is disclosed including a printed circuit board (PCB) including a plurality of traces, at least one processor mounted to the PCB to couple to some of the plurality of traces, a heterogeneous memory channel including a plurality of sockets coupled to a memory channel bus of the PCB, and a memory controller coupled between the at least one processor and the heterogeneous memory channel. The heterogeneous memory channel includes a plurality of sockets coupled to a memory channel bus of the PCB. The plurality of sockets are configured to receive a plurality of different types of memory modules. The memory controller may be a programmable heterogeneous memory controller to flexibly adapt to the memory channel bus to control access to each of the different types of memory modules in the heterogeneous memory channel.
    Type: Grant
    Filed: September 28, 2007
    Date of Patent: December 6, 2011
    Assignee: Virident Systems, Inc.
    Inventors: Kenneth Alan Okin, George Moussa, Kumar Ganapathy, Vijay Karamcheti, Rajesh Parekh
  • Patent number: 8074190
    Abstract: A circuit design system, methodology, and software are disclosed for generating circuit capable of consuming less dynamic power. In particular, the circuit design methodology entails modifying an initial circuit design including a clock network coupled to a plurality of edge-triggered flip-flops to generate a modified circuit design that uses pulsed latches driven by pulse generators in place of at least some of the flip-flops. Since pulsed latches use less dynamic power than edge-triggered flip-flops, the modified circuit may consume less dynamic power. The circuit design methodology may further entail adding delay cells for balancing the clock network to compensate for timing effects caused by the insertion of pulse generators. Additionally, the methodology may further include cloning of forbidden clock paths to make more flip-flops eligible for pulsed latch replacement.
    Type: Grant
    Filed: March 4, 2010
    Date of Patent: December 6, 2011
    Assignee: Cadence Design Systems, Inc.
    Inventors: Hung-Chun Li, Ming-Chyuan Chen, KunMing Ho
  • Patent number: 8063686
    Abstract: In one embodiment of the invention, a method is disclosed to generate a clock output signal with selected phase. The method includes selecting a phase delay for the clock output signal; charging a capacitor with a first weighted current during a first phase input clock, charging the capacitor with a second weighted current during a portion of a second phase input clock, and determining if a voltage across the capacitor is greater than or equal to a threshold voltage to generate a first edge of the clock output signal with the selected phase delay. The first weighted current may have a weighting of N out of M to charge the capacitor with a predetermined rate of change in voltage in response to the selected phase delay. The second weighted current may have a weighting of M out of M to charge the capacitor with a constant rate of change.
    Type: Grant
    Filed: November 13, 2008
    Date of Patent: November 22, 2011
    Assignee: Cadence Design Systems, Inc.
    Inventors: Eric Naviasky, Thomas E. Wilson
  • Patent number: 8065640
    Abstract: In one embodiment of the invention, a method is disclosed including executing one or more commands of a work script to perform work on a portion of a netlist of an integrated circuit design; receiving an indication of a program fault in a first integrated circuit (IC) design program performing work on the portion of the netlist in response to the one or more commands of the work script; and generating a debug work script associated with the work script in response to the program fault, the debug work script including an identification of the portion of the netlist of the integrated circuit design upon which work was being performed during the program fault.
    Type: Grant
    Filed: May 30, 2007
    Date of Patent: November 22, 2011
    Assignee: Cadence Design Systems, Inc.
    Inventors: Sascha Richter, Denis Baylor
  • Patent number: 8051253
    Abstract: A computer system is disclosed including a printed circuit board (PCB) including a plurality of traces, at least one processor mounted to the PCB to couple to some of the plurality of traces, a heterogeneous memory channel including a plurality of sockets coupled to a memory channel bus of the PCB, and a memory controller coupled between the at least one processor and the heterogeneous memory channel. The heterogeneous memory channel includes a plurality of sockets coupled to a memory channel bus of the PCB. The plurality of sockets are configured to receive a plurality of different types of memory modules. The memory controller may be a programmable heterogeneous memory controller to flexibly adapt to the memory channel bus to control access to each of the different types of memory modules in the heterogeneous memory channel.
    Type: Grant
    Filed: September 28, 2007
    Date of Patent: November 1, 2011
    Assignee: Virident Systems, Inc.
    Inventors: Kenneth Alan Okin, George Moussa, Kumar Ganapathy, Vijay Karamcheti, Rajesh Parekh
  • Patent number: 7945880
    Abstract: In one embodiment of the invention, a method of retiming a circuit is disclosed. The method includes computing an upper bound and a lower bound for a clock period of a clock signal to clock a circuit in response to a netlist of the circuit; selecting a potential clock period for the clock signal to clock registers of the circuit in response to the computed upper bound and the computed lower bound for the clock period; computing an upper bound and a lower bound of a retiming value for each node of the circuit to determine if a retiming of the circuit is achievable with the potential clock period; and computing the retiming value for each node of the circuit to minimize circuit area in response to the computed upper bound and the computed lower bound of the retiming value for each node.
    Type: Grant
    Filed: May 30, 2007
    Date of Patent: May 17, 2011
    Assignee: Cadence Design Systems, Inc.
    Inventors: Christoph Albrecht, Sascha Richter
  • Patent number: 7933748
    Abstract: A system, method, and software program for facilitating the assignment of cell specifications to a plurality of cells of a system design. The methods include generating a plurality of candidate cell specifications that meet the specification for the system design. In one embodiment, the method entails using information related to intra-range preference for cell specifications to generate a set of alternative system pareto-optimal solutions which define a boundary of a region of candidate cell specifications. In another embodiment, the method entails generating a substantially uniform set of candidate cell specifications using a prediction-based performance model, such as support vector regression model or cluster-weighted model, an optimizing algorithm such as conjugate-gradient or Markov Chain Monte Carlo Method, and a sample density model.
    Type: Grant
    Filed: December 18, 2007
    Date of Patent: April 26, 2011
    Assignee: Cadence Design Systems, Inc.
    Inventors: Stephen McCracken, Enis Aykut Dengi, Xuejin Wang
  • Patent number: 7926011
    Abstract: A system and method of designing an integrated circuit capable of deriving timing constraints for individual block-level circuits of an integrated circuit that are derived from the chip-level timing constraints and analysis. The block-level timing constraints are in the form of one or more logical timing constraint points at the input and output ports of block-level circuits. Each logical timing constraint points specifies a clock source used to clock data through the port, a delay parameter specifying data propagation delay backward from an input port and forward from an output port, and any timing exception associated with the data path. Using the logical timing constraint point, the circuit design system performs independent timing analysis and optimization of each block-level circuit. The system then reassembles the block-level circuits into a modified chip-level circuit for which timing closure can be achieved.
    Type: Grant
    Filed: January 10, 2007
    Date of Patent: April 12, 2011
    Assignee: Cadence Design Systems, Inc.
    Inventors: Oleg Levitsky, Chien-Chu Kuo, Dinesh Gupta
  • Patent number: 7911288
    Abstract: To reduce cross-talk, an integrated circuit may include a uniform signal trace for a first signal; and a pair of non-uniform signal traces forming a differential pair for a differential signal. The pair of non-uniform signal traces near the uniform signal trace.
    Type: Grant
    Filed: June 30, 2008
    Date of Patent: March 22, 2011
    Assignee: Cadence Design Systems, Inc.
    Inventor: Syed Assadulla Bokhari
  • Patent number: 7913194
    Abstract: In one embodiment of the invention, a method is disclosed including receiving a netlist of an integrated circuit design; executing a first copy of an integrated circuit design program with a first processor associated with a first memory space to independently perform work on a first portion of the integrated circuit design; and executing a second copy of the integrated circuit design program with a second processor associated with a second memory space to independently perform work on a second portion of the integrated circuit design; wherein the second memory space is independent of the first memory space.
    Type: Grant
    Filed: May 31, 2007
    Date of Patent: March 22, 2011
    Assignee: Cadence Design Systems, Inc.
    Inventor: Denis Baylor
  • Patent number: 7886238
    Abstract: Systems and methods to optimize a layout based on the yield analysis is disclosed. The method includes generating an integrated circuit layout having two or more layers of wire interconnect to form net segments and having one or more via contact layers to couple net segments in the wire interconnect together. The method further includes performing a yield analysis of the net segments in the integrated circuit layout and displaying the net segments with a visual depiction of the yield analysis using multiple levels of opacity to reflect yield scores of the net segments in the integrated circuit layout.
    Type: Grant
    Filed: November 28, 2006
    Date of Patent: February 8, 2011
    Assignee: Cadence Design Systems, Inc.
    Inventors: Harsh Dev Sharma, Rajeev Srivastava, Srinivas R. Kommoori, Bharat Bhushan, Mithunjoy Parui, Albert Lee
  • Patent number: 7886242
    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: August 21, 2007
    Date of Patent: February 8, 2011
    Assignee: Cadence Design Systems, Inc.
    Inventors: Swapnajit Chakraborti, Sandeep Pagey, Boris Gommershtadt, Yael Duek-Golan
  • Patent number: 7882471
    Abstract: In one embodiment of the invention, a method of statically analyzing an integrated circuit with process and environment variations is provided. The method includes characterizing each circuit cell of a cell library for a sensitivity to process parameter variations within a predetermined range; creating a timing graph corresponding to a netlist representing an integrated circuit design; along nodes of the timing graph, computing delay values including sensitivities to process variations; for each selected output node of the netlist, propagating a full timing value function with the sensitivities to the selected output nodes; and generating a parameterized timing report including the sensitivities to the process variations.
    Type: Grant
    Filed: November 15, 2006
    Date of Patent: February 1, 2011
    Assignee: Cadence Design Systems, Inc.
    Inventors: Vinod Kariat, Joel R. Phillips, Igor Keller
  • Patent number: 7823116
    Abstract: In embodiment of the invention, a method of synthesizing a layout of an integrated circuit chip including analog circuitry is disclosed. The method includes receiving a circuit netlist of an integrated circuit chip including analog circuitry; representing and manipulating a hierarchical analog circuit layout including device placement and net routing in response to the circuit netlist, the hierarchical analog circuit layout including a plurality of levels of layout hierarchy; and passing layout information from one level of the layout hierarchy to an adjacent level of the layout hierarchy to synthesize the layout of the integrated circuit chip.
    Type: Grant
    Filed: June 2, 2007
    Date of Patent: October 26, 2010
    Assignee: SynCira Corporation
    Inventor: Shufan Chan
  • Patent number: 7774735
    Abstract: A method for migrating a netlist from one set of library cells to a new set of library cells with minimal time and effort and without loss of information within an ASCI environment. This methodology ensures that during translation logic equivalence and scan configurations are maintained in the new technology libraries. Additionally, a complete migration of the constraints from the original netlist to the new netlist is also performed. Designer engineers no longer have to start from RTL and execute a complete resynthesis to translate an original design from one technology library to a new technology library.
    Type: Grant
    Filed: March 7, 2007
    Date of Patent: August 10, 2010
    Assignee: Cadence Design Systems, Inc
    Inventor: Ankush Sood
  • Patent number: 7761623
    Abstract: An apparatus includes a printed circuit board with a plurality of printed circuit board traces, a memory controller mounted on the printed circuit board coupled to one or more of the plurality of printed circuit board traces, a plurality of non-volatile type of memory integrated circuits coupled to the printed circuit board, and a plurality of support integrated circuits coupled between the memory controller and the plurality of non-volatile type of memory integrated circuits.
    Type: Grant
    Filed: August 30, 2007
    Date of Patent: July 20, 2010
    Assignee: Virident Systems, Inc.
    Inventors: Vijay Karamcheti, Kumar Ganapathy, Kenneth Alan Okin, Rajesh Parekh
  • Patent number: 7761836
    Abstract: In one embodiment of the invention, an object oriented autorouter is disclosed for routing nets in a circuit. The object oriented autorouter includes a routing data model (RDM); at least one routing engine, such as a single connection router (SCR), a topographical (TOPO) transformation engine, and a detail geometric (DETAIL) engine, and a command and control module (CCM) coupled together. The RDM reads and write data with a design database as well as reading one or more object oriented design constraints. Each of the routing engines have at least one action to operate on the design database to improve compliance of the circuit to a constraint. The CCM controls the overall routing process of the nets in the circuit and includes at least one director to invoke at least one of the routing engines to achieve compliance with one or more constraints.
    Type: Grant
    Filed: October 11, 2006
    Date of Patent: July 20, 2010
    Assignee: Cadence Design Systems, Inc.
    Inventors: Ken Wadland, Sean Bergan, Charles W. Grant, Glendine Kingsbury, Randall Lawson, Jelena Radumilo-Franklin, Kota Sujan Reddy, Steve Russo, William Schilp, Davis Tsai, Keith Woodward, Richard Woodward, Jia Wu
  • Patent number: 7761626
    Abstract: An apparatus includes a printed circuit board with a plurality of printed circuit board traces, a memory controller mounted on the printed circuit board coupled to one or more of the plurality of printed circuit board traces, a plurality of non-volatile type of memory integrated circuits coupled to the printed circuit board, and a plurality of support integrated circuits coupled between the memory controller and the plurality of non-volatile type of memory integrated circuits.
    Type: Grant
    Filed: August 30, 2007
    Date of Patent: July 20, 2010
    Assignee: Virident Systems, Inc.
    Inventors: Vijay Karamcheti, Kumar Ganapathy, Kenneth Alan Okin, Rajesh Parekh