Patents Represented by Attorney Wheelock Chan LLP
  • Patent number: 7836419
    Abstract: Method and system for partitioning integrated circuits are disclosed. The method includes receiving a netlist representation of the circuit comprising circuit components, partitioning the circuit to form one or more circuit partitions according to a predefined partitioning method, where each circuit partition includes one or more circuit components. The method further includes, for each circuit partition, identifying substantial correlations between the circuit partition and one or more other circuit partitions to form a spanning tree, where the spanning tree connects the circuit partition to the one or more other circuit partitions via a graph, and merging the circuit partition and the one or more other circuit partitions in the spanning tree to form a new circuit partition.
    Type: Grant
    Filed: March 27, 2006
    Date of Patent: November 16, 2010
    Assignee: Cadence Design Systems, Inc
    Inventors: Bruce W. McGaughy, Jun Kong
  • Patent number: 7835890
    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: October 4, 2007
    Date of Patent: November 16, 2010
    Assignee: Cadence Design Systems, Inc.
    Inventors: Lifeng Wu, Zhihong Liu, Alvin I. Chen, Jeong Y. Choi, Bruce W. McGaughy
  • Patent number: 7657416
    Abstract: A method of system design, and more particularly a method of designing systems that achieve a set of performance goals using a hierarchically partitioned system representation wherein performance simulations are performed at multiple levels within the hierarchy and are combined to simulate a system level result in order to reduce the aggregate time required for performance simulation.
    Type: Grant
    Filed: August 12, 2005
    Date of Patent: February 2, 2010
    Assignee: Cadence Design Systems, Inc
    Inventors: Pero Subasic, Enis Aykut Dengi
  • Patent number: 7584440
    Abstract: The present invention relates to a method and system for tuning a circuit. In one embodiment, the method includes receiving a description of the circuit, and selecting a design point of the circuit for evaluation using a sizing tool, where the design point comprises a design of the circuit that meets a set of predefined design specifications, and the circuit comprises a group of circuit devices. The method further includes receiving a set of tuning information for the group of circuit devices tuning the group of circuit devices using the set of tuning information to create a group of tuned circuit devices, creating an updated layout of the group of tuned circuit devices using a layout tool, creating estimated parasitic information of the group of tuned circuit devices using the updated layout, and verifying the design point meets design goals of the circuit using the estimated parasitic information of the updated layout.
    Type: Grant
    Filed: October 12, 2006
    Date of Patent: September 1, 2009
    Assignee: Cadence Design Systems, Inc.
    Inventors: Rongchang Yan, Prakash Gopalakrishnan
  • Patent number: 7532149
    Abstract: One embodiment of a rearview mirror encompassing a plurality of radar detectors and laser detectors comprises of an opaque housing, a rearview mirror assembly, a universal mount, and a PCB assembly providing all of the illumination, audible indication, logic, user inputs, and radar and laser detection. Visual indications of radar or laser signals via illuminated indicators visible through the mirror, provide a fully functioning rearview mirror, when in standby mode. The device accommodates a plurality of mounts in order to accommodate all vehicle types. The geometry and mounting locations provide for more sensitive and accurate detection of radar and laser signals, while neither distracting the drive, detracting from the aesthetic nature of the vehicle, or causing a safety hazard.
    Type: Grant
    Filed: October 4, 2007
    Date of Patent: May 12, 2009
    Assignee: Banko Industries
    Inventors: Sarah V. Banko, Joshua D. Banko
  • Patent number: 7533358
    Abstract: Method and system are disclosed for designing a circuit using an integrated sizing, layout, and extractor tool. In one embodiment, a method for designing a circuit including initializing a set of design points, where a design point comprises a design of the circuit that meets a set of predefined design specifications, determining sizes for the circuit using a size optimization iteration process, and pausing the sizing optimization iteration process periodically for updating parasitic information of the circuit. The method further includes selecting a subset of design points from the set of design points, generating a layout of the circuit using devices sizes obtained from the set of design points, generating an extracted netlist using the layout, wherein the extracted netlist includes parasitic information of the circuit, and simulating the circuit using the extracted netlist to verify the set of predefined design specifications are met.
    Type: Grant
    Filed: October 12, 2006
    Date of Patent: May 12, 2009
    Assignee: Cadence Design Systems, Inc.
    Inventors: Prakash Gopalakrishnan, Hongzhou Liu
  • Patent number: 7523424
    Abstract: System and method for representing analog connectivity in a design written in a hardware description language are disclosed. The method includes detecting a circuit component that does not have explicit connection path in the design, where the circuit component includes one or more lower-level circuit instances arranged in one or more branches in a hierarchical graph. The method further includes creating one or more instances of the circuit component having at least one additional port than the circuit component, creating one or more ports in the corresponding one or more instances of the circuit component for providing at least an explicit connection path, and representing the design using at least the explicit connection path and the one or more ports of the corresponding one or more instances.
    Type: Grant
    Filed: November 30, 2005
    Date of Patent: April 21, 2009
    Assignee: Cadence Design Systems, Inc.
    Inventors: Abhijeet Kolpekwar, Scott Cranston, Peter Frey
  • Patent number: 7518992
    Abstract: Methods and apparatus for use in a network including a local server coupled to a central server, the local server being coupled to a plurality of network devices, for interactively controlling from one of the plurality of network devices a flow of audio visual data from the central server to the network device, comprising obtaining a control command at the network device, the control command indicating a desired modification to the flow of the audio visual data from the central server to the network device. The control command is sent from the network device to the central server via the local server. A modified flow of the audio visual data is then received from the central server at the network device in response to the control command.
    Type: Grant
    Filed: April 24, 2006
    Date of Patent: April 14, 2009
    Inventor: Hensen Mou
  • Patent number: 7497866
    Abstract: These methods, devices, and structures are useful in the field of ophthalmology; the devices and methods relate variously to separating or lifting corneal epithelium from the eye preferably in a substantially continuous layer, placing a lens or other suitable ocular or medical device beneath the epithelial membrane, and to the resulting structures formed by those procedures. The de-epilthelialization devices generally utilize a non-cutting separator or dissector that is configured to separate the epithelium at a naturally occurring cleavage surface in the eye between the epithelium and the corneal stroma (Bowman's membrane), specifically separating in the region of the lamina lucida. The separator or dissector may have a structure that rolls or vibrates (or both) at that cleavage surface or interface during the dissection step. The separated epithelium may be lifted or peeled from the surface of the eye to form an epithelial flap or a pocket.
    Type: Grant
    Filed: January 17, 2003
    Date of Patent: March 3, 2009
    Assignee: Tissue Engineering Refraction Inc.
    Inventor: Edward Perez
  • Patent number: 7493574
    Abstract: Method and system for improving yield of an integrated circuit are disclosed. The method includes optimizing a design of the integrated circuit according to a set of predefined design parameters to generating design points that meet a set of predefined design specifications, analyzing the design points to form clusters comprising the design points, determining a representative design point from the clusters comprising the design points, running a statistical simulation to determine a yield of the design using the representative design point and a statistical model of manufacturing process variations, generating statistical corners in accordance with results of the statistical simulation, and optimizing the design in accordance with the statistical corners using an iterative process.
    Type: Grant
    Filed: February 23, 2006
    Date of Patent: February 17, 2009
    Assignee: Cadence Designs Systems, Inc.
    Inventors: Hongzhou Liu, Rodney M. Phelps
  • Patent number: 7434183
    Abstract: System and method for validating a circuit for simulation are disclosed. The system includes at least one processing unit for executing computer programs, a graphical user interface for viewing representations of the circuit on a display, a memory for storing information of the circuit, and logic for representing the circuit in a hierarchical data structure, where the hierarchical data structure has a plurality of subcircuits arranged in a connected graph, and where each subcircuit has circuit elements and one or more input and output ports. The system further includes logic for traversing the hierarchical data structure in a bottom-up fashion, logic for recording input port to output port (port-to-port) properties of the subcircuits in the hierarchical data structure, logic for traversing the hierarchical data structure in a top-down fashion, and logic for identifying illegal port paths using the port-to-port properties of the subcircuits.
    Type: Grant
    Filed: August 17, 2005
    Date of Patent: October 7, 2008
    Assignee: Cadence Design Systems, Inc.
    Inventors: Bruce W. McGaughy, Jun Kong
  • Patent number: 7418683
    Abstract: A computer aided design tool and method for designing IC layouts by recommending subcircuit layout constraints based upon an automated identification from a circuit schematic of subcircuit types requiring special IC layout constraints. Subcircuit types are identified on the basis of netlist examination, as well as cues from the layout of the circuit schematic.
    Type: Grant
    Filed: September 21, 2005
    Date of Patent: August 26, 2008
    Assignee: Cadence Design Systems, Inc
    Inventors: Jean-Daniel Sonnard, Zhigang Wang, Hemanth Sampath
  • Patent number: 7415403
    Abstract: A method for simulating analog behavior of a circuit in a simulation system includes representing the circuit as a hierarchically arranged set of branches, which includes a root branch and a plurality of other branches logically organized in a graph. The hierarchically arranged set of branches includes a first branch that has one or more subcircuits and a second branch that also has one or more subcircuits. The first branch and second branch are interconnected in the graph through a third branch at a higher hierarchical level in the graph than the first and second branches.
    Type: Grant
    Filed: February 15, 2005
    Date of Patent: August 19, 2008
    Assignee: Cadence Design Systems, Inc.
    Inventor: Bruce W. McGaughy
  • Patent number: 7412681
    Abstract: A computer implemented method is provided for use in evaluating a hierarchical representation of a circuit design encoded in a computer readable medium comprising: traversing a circuit path within a higher level circuit that includes a reference potential connection, to identify a port of a call to a first lower level circuit that is DC path connected to the reference potential; identifying a first DC port group that includes each port of the call to the first lower level circuit that is DC path connected to the identified port of the call to the first lower level circuit; automatically marking as DC path connected to the reference potential, each port of the call to the first lower level circuit that is a member of the first DC port group; and traversing a circuit path within the first lower level circuit to identify a circuit path within the first lower level circuit that is DC path connected to a marked port of the first lower level circuit.
    Type: Grant
    Filed: February 25, 2005
    Date of Patent: August 12, 2008
    Assignee: Cadence Design Systems, Inc.
    Inventors: Xiaodong Zhang, Jun Kong, Bruce W. McGaughy
  • Patent number: 7409328
    Abstract: A system for communicating simulation solutions between circuit components in a hierarchical data structure includes a simulator module having one or more computer programs for representing the circuit as a hierarchically arranged set of branches, which includes a root branch and a plurality of other branches logically organized in a graph. The hierarchically arranged set of branches includes a first branch that contains one or more driver leaf circuits and a second branch that also contains one or more receiver leaf circuits, where the first branch and second branch are interconnected in the graph through a third branch at a higher hierarchical level in the graph than the first and second branches.
    Type: Grant
    Filed: November 13, 2003
    Date of Patent: August 5, 2008
    Assignee: Cadence Design Systems, Inc.
    Inventors: Bruce W. McGaughy, Jun Kong, Peter Frey, Jaideep Muhkerjee
  • Patent number: 7392170
    Abstract: A system for dynamically compressing circuit components during simulating of a circuit having a hierarchical data structure includes a simulator module having one or more computer programs for 1) selecting a group of leaf circuits from the first and second branches for simulation, 2) if two or more leaf circuits of the circuit having a substantially same isomorphic behavior, representing the two or more leaf circuits as a merged leaf circuit, 3) creating a first port connectivity interface dynamically for the group of leaf circuits in response to the merged leaf circuit, where the first port connectivity interface communicates changes in signal conditions among the group of leaf circuits, and 4) simulating the group of leaf circuits in accordance with the first port connectivity interface.
    Type: Grant
    Filed: November 13, 2003
    Date of Patent: June 24, 2008
    Assignee: Cadence Design Systems, Inc.
    Inventors: Bruce W. McGaughy, Jun Kong
  • Patent number: 7373289
    Abstract: Method and system for determining electrical isomorphism between two electrical networks are disclosed. In one embodiment, the method includes representing the circuit as a hierarchically-arranged set of branches. The hierarchically-arranged set of branches including a first branch that includes a first electrical network and a second branch that includes a second electrical network, where the first and second branches are interconnected in the graph through a third branch at a higher hierarchical level in the graph than the first and second branches. Next, the method determines whether the first and second electrical networks are electrically isomorphic networks. If the first and second electrical networks are determined to be electrically isomorphic networks, the first and second electrical networks are represented with a single electrically isomorphic network. The method further includes simulating the first and second electrical networks using the single electrically isomorphic network.
    Type: Grant
    Filed: November 19, 2004
    Date of Patent: May 13, 2008
    Assignee: Cadence Design Systems, Inc
    Inventors: Bruce W. McGaughy, Wai Chung William Au, Baolin Yang