Patents by Inventor Douglas Chang

Douglas Chang has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 11694016
    Abstract: A method includes receiving a netlist for a chip including a bus and determining, by one or more processors and based on the netlist, a first routing topology for the bus and through a routing region of the chip by comparing a demand of the bus to a capacity of a plurality of cells of the routing region. The method also includes generating a layout for the chip based on the first routing topology.
    Type: Grant
    Filed: June 11, 2021
    Date of Patent: July 4, 2023
    Assignee: Synopsys, Inc.
    Inventors: Zhengtao Yu, Balkrishna Rashingkar, David Peart, Douglas Chang, Yiding Han
  • Publication number: 20220411025
    Abstract: A floating power-generation group comprises a floating hub such as a spar buoy that is anchored to subsea foundations by anchor lines. Floating power producer units such as wind turbines are connected electrically and mechanically to the hub. The power producer units are each moored by mooring lines. At least one mooring line extends inwardly toward the hub to effect mechanical connection to the hub and at least one other mooring line extends outwardly toward a subsea foundation. The groups are combined as a set whose hubs are connected electrically to each other via subsea energy storage units. Anchor lines of different groups can share subsea foundations. The storage units comprise pumping machinery to expel water from an elongate storage volume and generating machinery to generate electricity from a flow of water entering the storage volume. The pumping machinery may be in deeper water than the generating machinery.
    Type: Application
    Filed: October 22, 2020
    Publication date: December 29, 2022
    Inventors: Paul Douglas Chang, Ernst Kristen Helgoy Kloster
  • Publication number: 20220300687
    Abstract: A system determines physical design information along a logic hierarchy of a circuit design. The system accesses physical design metrics associated with different parts of a physical design of a circuit. The system accesses a logic design of the circuit comprising a hierarchy of logic blocks. The system determines the physical design metrics associated with one or more logic blocks of the hierarchy of the logic design based on a relation between the physical design and the logic design. The system configures a user interface to display the hierarchy of the logic design of the circuit along with the physical design metrics associated with the one or more logic blocks of the hierarchy. The system sends the configured user interface for display.
    Type: Application
    Filed: March 15, 2022
    Publication date: September 22, 2022
    Inventors: Amit Jalota, Andrew Saunders, Aruna Kanagaraj, Douglas Chang, Eshwari Rajendran, Prashant Gupta, Rajeev Murgai, Soumitra Majumder, Vasiliki Chatzi, Balkrishna Ramchandra Rashingkar
  • Publication number: 20210390241
    Abstract: A method includes receiving a netlist for a chip including a bus and determining, by one or more processors and based on the netlist, a first routing topology for the bus and through a routing region of the chip by comparing a demand of the bus to a capacity of a plurality of cells of the routing region. The method also includes generating a layout for the chip based on the first routing topology.
    Type: Application
    Filed: June 11, 2021
    Publication date: December 16, 2021
    Inventors: Zhengtao YU, Balkrishna RASHINGKAR, David PEART, Douglas CHANG, Yiding HAN
  • Patent number: 10318692
    Abstract: Some embodiments can receive a netlist for the circuit design, wherein the netlist is divided into a set of blocks and a top-level netlist. Next, the embodiments can create (1) a top-level netlist abstraction based on the top-level netlist, and (2) for each block in the set of blocks, create a block abstraction based on a portion of the netlist that is in the block and create virtual pin cells in the block, wherein each virtual pin cell corresponds to a connection that crosses a boundary of the block. The embodiments can then place the top-level netlist abstraction in the layout area, the set of blocks in the layout area, the block abstractions in corresponding blocks, and the virtual pin cells in corresponding blocks. The placed circuit abstraction can then be used to drive standard cell placement in the circuit design.
    Type: Grant
    Filed: March 23, 2015
    Date of Patent: June 11, 2019
    Assignee: SYNOPSYS, INC.
    Inventors: Douglas Chang, Balkrishna R. Rashingkar
  • Publication number: 20160283632
    Abstract: Some embodiments can receive a netlist for the circuit design, wherein the netlist is divided into a set of blocks and a top-level netlist. Next, the embodiments can create (1) a top-level netlist abstraction based on the top-level netlist, and (2) for each block in the set of blocks, create a block abstraction based on a portion of the netlist that is in the block and create virtual pin cells in the block, wherein each virtual pin cell corresponds to a connection that crosses a boundary of the block. The embodiments can then place the top-level netlist abstraction in the layout area, the set of blocks in the layout area, the block abstractions in corresponding blocks, and the virtual pin cells in corresponding blocks. The placed circuit abstraction can then be used to drive standard cell placement in the circuit design.
    Type: Application
    Filed: March 23, 2015
    Publication date: September 29, 2016
    Applicant: SYNOPSYS, INC.
    Inventors: Douglas Chang, Balkrishna R. Rashingkar
  • Patent number: 9026974
    Abstract: Methods and apparatuses are described for facilitating a user to explore and evaluate different options during floorplanning. Some embodiments display a graphical representation of a circuit design floorplan, wherein the graphical representation includes a set of blocks and a set of flylines between blocks, wherein each block corresponds to a portion of the circuit design, and wherein each flyline corresponds to one or more relationships between two blocks. Additionally, a set of metrics associated with one or more blocks or one or more flylines can be displayed. Next, in response to receiving a modification to one or more blocks in the graphical representation, the embodiments can update the set of metrics without performing expensive netlist modification, placement, routing, and/or propagation of timing information through multiple levels of logic, and then display the updated set of metrics.
    Type: Grant
    Filed: December 24, 2013
    Date of Patent: May 5, 2015
    Assignee: Synopsys, Inc.
    Inventors: Russell B. Segal, Balkrishna R. Rashingkar, Douglas Chang, Mattias A. Hembruch
  • Patent number: 8910097
    Abstract: Systems and techniques for creating a netlist abstraction are described. During operation, an embodiment can receive a netlist for a circuit design, wherein circuit elements in the circuit design are organized in a logical hierarchy (LH). Next, the embodiment can receive a set of LH nodes in the LH. The embodiment can then create the netlist abstraction by, for each LH node in the set of LH nodes, replacing a portion of the netlist that is below the LH node by a star netlist, wherein the star netlist includes a center object that is electrically connected to a set of satellite objects, wherein each satellite object corresponds to a port of the LH node.
    Type: Grant
    Filed: March 22, 2013
    Date of Patent: December 9, 2014
    Assignee: Synopsys, Inc.
    Inventors: Douglas Chang, Balkrishna R. Rashingkar
  • Patent number: 8893073
    Abstract: Methods and apparatuses are described for creating, editing, and viewing a floorplan of a circuit design. Specifically, some embodiments enable a user to perform a graphical operation at an inference point in a circuit design layout, wherein the location of the inference point is determined based on existing graphical objects in the circuit design layout. Some embodiments substantially instantaneously update a congestion indicator in a circuit design layout in response to modifying the circuit design layout. Some embodiments substantially instantaneously update pin locations of a block or partition in response to changing the size or shape of the block or partition. Some embodiments enable a user to view a circuit design layout based on the logical hierarchy, and also based on at least one additional attribute type such as voltage, power, or clock domain.
    Type: Grant
    Filed: December 27, 2012
    Date of Patent: November 18, 2014
    Assignee: Synopsys, Inc.
    Inventors: Balkrishna R. Rashingkar, David L. Peart, Russell Segal, Douglas Chang, Ksenia Roze
  • Publication number: 20140189617
    Abstract: Methods and apparatuses are described for creating, editing, and viewing a floorplan of a circuit design. Specifically, some embodiments enable a user to perform a graphical operation at an inference point in a circuit design layout, wherein the location of the inference point is determined based on existing graphical objects in the circuit design layout. Some embodiments substantially instantaneously update a congestion indicator in a circuit design layout in response to modifying the circuit design layout. Some embodiments substantially instantaneously update pin locations of a block or partition in response to changing the size or shape of the block or partition. Some embodiments enable a user to view a circuit design layout based on the logical hierarchy, and also based on at least one additional attribute type such as voltage, power, or clock domain.
    Type: Application
    Filed: December 27, 2012
    Publication date: July 3, 2014
    Applicant: SYNOPSYS, INC.
    Inventors: Balkrishna R. Rashingkar, David L. Peart, Russell Segal, Douglas Chang, Ksenia Roze
  • Publication number: 20140189620
    Abstract: Systems and techniques for creating a netlist abstraction are described. During operation, an embodiment can receive a netlist for a circuit design, wherein circuit elements in the circuit design are organized in a logical hierarchy (LH). Next, the embodiment can receive a set of LH nodes in the LH. The embodiment can then create the netlist abstraction by, for each LH node in the set of LH nodes, replacing a portion of the netlist that is below the LH node by a star netlist, wherein the star netlist includes a center object that is electrically connected to a set of satellite objects, wherein each satellite object corresponds to a port of the LH node.
    Type: Application
    Filed: March 22, 2013
    Publication date: July 3, 2014
    Applicant: Synopsys, Inc.
    Inventors: Douglas Chang, Balkrishna R. Rashingkar
  • Publication number: 20140181776
    Abstract: Methods and apparatuses are described for facilitating a user to explore and evaluate different options during floorplanning. Some embodiments display a graphical representation of a circuit design floorplan, wherein the graphical representation includes a set of blocks and a set of flylines between blocks, wherein each block corresponds to a portion of the circuit design, and wherein each flyline corresponds to one or more relationships between two blocks. Additionally, a set of metrics associated with one or more blocks or one or more flylines can be displayed. Next, in response to receiving a modification to one or more blocks in the graphical representation, the embodiments can update the set of metrics without performing expensive netlist modification, placement, routing, and/or propagation of timing information through multiple levels of logic, and then display the updated set of metrics.
    Type: Application
    Filed: December 24, 2013
    Publication date: June 26, 2014
    Applicant: Synopsys, Inc.
    Inventors: Russell B. Segal, Balkrishna R. Rashingkar, Douglas Chang, Mattias A. Hembruch
  • Patent number: 8037442
    Abstract: One embodiment of the present invention provides a system that scales an I/O-cell placement during die-size optimization. During operation, the system starts by receiving an initial die-size for a die and an initial I/O-cell placement for a set of I/O cells. The system also receives a target die-size for the die. The system then determines die-size changes between the initial die-size and the target die-size. Next, the system identifies available spaces between the set of I/O cells in the initial I/O-cell placement. The system subsequently scales the initial I/O-cell placement based on the identified available spaces and the die-size changes to obtain a new I/O-cell placement which fits in the target die-size.
    Type: Grant
    Filed: November 26, 2008
    Date of Patent: October 11, 2011
    Assignee: Synopsys, Inc.
    Inventors: Peiqing Zou, Douglas Chang, Neeraj Kaul
  • Patent number: 8001514
    Abstract: One embodiment of the present invention provides a system that computes a routability estimation across a collection of local routing regions associated with a circuit layout. This system first selects a first local routing region associated with a route overflow, wherein a respective local routing region is associated with an estimation of a number of route overflows for routing layers in a region of the circuit layout. Furthermore, a respective routing layer is associated with a preferred direction variable D. Next, the system transfers an overflow value k in direction d away from an overflowing routing layer for the first local routing region to a second local routing region, which has the capacity to handle an overflow of k or more routes in a direction d. Finally, the system computes a global routability estimation as a function of a global overflow cost and an adjacent overflow cost.
    Type: Grant
    Filed: April 23, 2008
    Date of Patent: August 16, 2011
    Assignee: Synopsys, Inc.
    Inventors: Douglas Chang, Neeraj Kaul, Balkrishna Rashingkar
  • Publication number: 20100131913
    Abstract: One embodiment of the present invention provides a system that scales an I/O-cell placement during die-size optimization. During operation, the system starts by receiving an initial die-size for a die and an initial I/O-cell placement for a set of I/O cells. The system also receives a target die-size for the die. The system then determines die-size changes between the initial die-size and the target die-size. Next, the system identifies available spaces between the set of I/O cells in the initial I/O-cell placement. The system subsequently scales the initial I/O-cell placement based on the identified available spaces and the die-size changes to obtain a new I/O-cell placement which fits in the target die-size.
    Type: Application
    Filed: November 26, 2008
    Publication date: May 27, 2010
    Applicant: SYNOPSYS, INC.
    Inventors: Peiqing Zou, Douglas Chang, Neeraj Kaul
  • Publication number: 20090271754
    Abstract: One embodiment of the present invention provides a system that computes a routability estimation across a collection of local routing regions associated with a circuit layout. This system first selects a first local routing region associated with a route overflow, wherein a respective local routing region is associated with an estimation of a number of route overflows for routing layers in a region of the circuit layout. Furthermore, a respective routing layer is associated with a preferred direction variable D. Next, the system transfers an overflow value k in direction d away from an overflowing routing layer for the first local routing region to a second local routing region, which has the capacity to handle an overflow of k or more routes in a direction d. Finally, the system computes a global routability estimation as a function of a global overflow cost and an adjacent overflow cost.
    Type: Application
    Filed: April 23, 2008
    Publication date: October 29, 2009
    Applicant: SYNOPSYS, INC.
    Inventors: Douglas Chang, Neeraj Kaul, Balkrishna Rashingkar
  • Patent number: 6285355
    Abstract: A mouse-associated Z-axis encoder mainly including a rotary-shaft mount, an encoding disc, and an encoding wheel, and being mounted in a mouse at a position corresponding to a mid-key of the mouse. The rotary-shaft mount has a connection seat provided to an upper portion thereof. A rotary shaft and a plurality of cylindrical sleeves are axially provided on the connection seat. Each of the cylindrical sleeves has a contact finger and an elastic element mounted therein. At least one of the contact fingers is connected to electric signals. The encoding disc is disposed in the encoding wheel so that they are together mounted around the rotary shaft. The encoding wheel is partially protruded from the mouse via the position for the mid-key. There are several series of connected or non-connected conductive contacting areas provided on the surface of the encoding disc.
    Type: Grant
    Filed: May 26, 1999
    Date of Patent: September 4, 2001
    Assignee: Key Mouse Electronic Enterprise Co.
    Inventor: Douglas Chang
  • Patent number: 5345253
    Abstract: A track ball base structure comprises a single-piece body having a housing being composed of a plurality of standing plates in the top of the body with extruding portions in the upper end of which to get secure connection to a cover, a central circular recess with an opening bottom to hold a ball therein, a plurality of ball bearing holes evenly distributed around the upper rim of the circular panel in the housing with an inner rectangular plate inside the uppermost of each hole for admitting ball bearings therein and at the same time holding them in place, multiple pairs of locking means and slots in both sides of the body for locking the detecting system as well as fixing the body substantially onto an integrated circuit plate. The present invention is characterized by providing a track ball base structure in a non-assembly manner. Therefore, the number of component parts required for the track ball is reduced and clearly any damage occurring under interconnection for each part can be eliminated.
    Type: Grant
    Filed: January 21, 1994
    Date of Patent: September 6, 1994
    Assignee: Behavior Tech Computer Corp.
    Inventor: Douglas Chang