Patents Represented by Attorney Preston J. Young
  • Patent number: 8340939
    Abstract: In one embodiment, the invention is a method and apparatus for selecting paths for use in at-speed testing. One embodiment of a method for selecting a set of n paths with which to test an integrated circuit chip includes: organizing the set of n paths into a plurality of sub-sets, receiving a new candidate path, and adding the new candidate path to one of the sub-sets when the new candidate path improves the process coverage metric of the sub-sets.
    Type: Grant
    Filed: October 30, 2009
    Date of Patent: December 25, 2012
    Assignee: International Business Machines Corporation
    Inventors: Yiyu Shi, Chandramouli Visweswariah, Jinjun Xiong, Vladimir Zolotov
  • Patent number: 8010926
    Abstract: Power, routability and electromigration have become crucial issues in modern microprocessor designs. In high performance designs, clocks are the highest consumer of power. Arranging clocking components with regularity so as to minimize the capacitance on the clock nets can help reduce clock power, however, it may hurt performance due to some loss of flexibility in physically placing those components. The present invention provides techniques to optimally place clock components in a regular fashion so as to minimize clock power within a performance constraint. A rectangular grid is created and clock distribution structures are assigned to the grid intersection points. Latches are then located around the clock distribution structures to minimize an overall distance for connections between the latches and respective clock distribution structures. The horizontal and vertical pitches of the grid may be independently adjusted to achieve a more uniform spread of the clock distribution structures.
    Type: Grant
    Filed: January 30, 2008
    Date of Patent: August 30, 2011
    Assignee: International Business Machines Corporation
    Inventors: Charles J. Alpert, Ruchir Puri, Shyam Ramji, Ashish K. Singh, Chin Ngai Sze
  • Patent number: 7911263
    Abstract: A dormant mode target semiconductor device within a leakage current target unit is identified for mitigating leakage current to prevent it from reaching catastrophic runaway. A leakage current shift monitor unit is electrically connected to the output node of the leakage current target unit and collects leakage current from the selected target semiconductor device for two consecutive predefined temporal periods and measures the difference between the collected leakage currents. A comparator receives and compares the outputs of the current shift monitor unit and a reference voltage generator. The comparator propagates an alert signal to the leakage current target unit when the leakage voltage output from the leakage current shift monitor unit exceeds the reference voltage, a condition that indicates that the leakage current is about to approach catastrophic runaway levels.
    Type: Grant
    Filed: June 30, 2009
    Date of Patent: March 22, 2011
    Assignee: International Business Machines Corporation
    Inventors: Jong-Ru Guo, Louis Lu-Chen Hsu, Rajiv Vasant Joshi, Ping-Chuan Wang, Zhijian Yang