Patents by Inventor Shyam Ramji

Shyam Ramji 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).

  • Publication number: 20080148203
    Abstract: A novel iterative latch placement scheme wherein the latches are gradually pulled by increasing attraction force until they are eventually placed next to a clock distribution structure such as a local clock buffer (LCB). During the iterations, timing optimizations such as gate sizing and re-buffering are invoked in order to keep the timing estimation accurate. By applying the iterative clock net weighting adjustment, the present invention allows tighter interaction between logic placement and clock placement which leads to higher quality timing and significant power savings.
    Type: Application
    Filed: December 14, 2006
    Publication date: June 19, 2008
    Inventors: Charles J. Alpert, Shyam Ramji, Chin Ngai Sze, Paul G Villarrubia
  • Patent number: 7089521
    Abstract: A method for resolving overlaps in the cell placement (placement legalization) during the physical design phase of an integrated chip design is described. This problem arises in several contexts within the physical design automation area including global and detailed placement, physical synthesis, and ECO (Engineering Change Order) mode for timing/design closure The method involves capturing a view of a given placement, solving a global two-dimensional area migration model and locally perturbing the cells to resolve the overlaps with minimal changes to the given placement. The method first captures a two-dimensional view of the placement including blockage-space, free-space and the given location of cells by defining physical regions. The desired global area migration across the physical regions of the placement image is determined such that it satisfies area capacity-demand constraints.
    Type: Grant
    Filed: January 27, 2004
    Date of Patent: August 8, 2006
    Assignee: International Business Machines Corporation
    Inventors: Zahi M. Kurzum, Paul Villarrubia, Shyam Ramji
  • Patent number: 7076755
    Abstract: A generalized method for optimizing the global placement of a VLSI chip across multiple cost metrics, such as total wire length, timing, congestion, and signal integrity is described. The method relies upon a “look ahead” technique, combined with any generic cost function that can be used to set placement directives. These placement directives include net weights and cell spreading. The method of performing the placement involves the iterative reuse of the process of successive partitioning. This iterative reuse establishes the capability of looking ahead to determine what is to happen. Based on the look ahead, it is possible to evaluate the qualities of the placement about to be generated. The method proceeds through the placement from while maintaining the current state of the placement along with the look-ahead state of the placement.
    Type: Grant
    Filed: January 27, 2004
    Date of Patent: July 11, 2006
    Assignee: International Business Machines Corporation
    Inventors: Haoxing Ren, Paul Villarrubia, Zahi M. Kurzum, Shyam Ramji
  • Publication number: 20050166164
    Abstract: A generalized method for optimizing the global placement of a VLSI chip across multiple cost metrics, such as total wire length, timing, congestion, and signal integrity is described. The method relies upon a “look ahead” technique, combined with any generic cost function that can be used to set placement directives. These placement directives include net weights and cell spreading. The method of performing the placement involves the iterative reuse of the process of successive partitioning. This iterative reuse establishes the capability of looking ahead to determine what is to happen. Based on the look ahead, it is possible to evaluate the qualities of the placement about to be generated. The method proceeds through the placement from while maintaining the current state of the placement along with the look-ahead state of the placement.
    Type: Application
    Filed: January 27, 2004
    Publication date: July 28, 2005
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Haoxing Ren, Paul Villarrubia, Zahi Kurzum, Shyam Ramji
  • Publication number: 20050166169
    Abstract: A method for resolving overlaps in the cell placement (placement legalization) during the physical design phase of an integrated chip design is described. This problem arises in several contexts within the physical design automation area including global and detailed placement, physical synthesis, and ECO (Engineering Change Order) mode for timing/design closure The method involves capturing a view of a given placement, solving a global two-dimensional area migration model and locally perturbing the cells to resolve the overlaps with minimal changes to the given placement. The method first captures a two-dimensional view of the placement including blockage-space, free-space and the given location of cells by defining physical regions. The desired global area migration across the physical regions of the placement image is determined such that it satisfies area capacity-demand constraints.
    Type: Application
    Filed: January 27, 2004
    Publication date: July 28, 2005
    Inventors: Zahi Kurzum, Paul Villarrubia, Shyam Ramji
  • Publication number: 20030217338
    Abstract: A method, computer software, and system for performing congestion mitigation in an IC design while preserving global logic order, comprising the steps of carrying out circuit block placement; measuring the congestion for each circuit block to determine if it exceeds a target value; reallocating area to circuit blocks that exceed said target value of congestion solely from adjacent circuit blocks; and removing overlap.
    Type: Application
    Filed: May 17, 2002
    Publication date: November 20, 2003
    Applicant: International Business Machines Corporation
    Inventors: Glenn E. Holmes, Zahi M. Kurzum, Shyam Ramji, Haoxing Ren, Paul G. Villarrubia