Patents by Inventor Ee K. Cho

Ee K. Cho 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: 7093208
    Abstract: A Digital Design Method which may be automated is for obtaining timing closure in the design of large, complex, high-performance digital integrated circuits. The methodincludes the use of a tuner on random logic macros that adjusts transistor sizes in a continuous domain. To accommodate this tuning, logic gates are mapped to parameterized cells for the tuning and then back to fixed gates after the tuning. Tuning is constrained in such a way as to minimize “binning errors” when the design is mapped back to fixed cells. Further, the critical sections of the circuit are marked in order to make the optimization more effective and to fit within the problem-size constraints of the tuner. A specially formulated objective function is employed during the tuning to promote faster global timing convergence, despite possibly incorrect initial timing budgets. The specially formulated objective function targets all paths that are failing timing, with appropriate weighting, rather than just targeting the most critical path.
    Type: Grant
    Filed: May 10, 2004
    Date of Patent: August 15, 2006
    Assignee: International Business Machines Corporation
    Inventors: Patrick M. Williams, Ee K. Cho, David J. Hathaway, Mei-Ting Hsu, Lawrence K. Lange, Gregory A. Northrop, Chandramouli Visweswariah, Cindy ShuiKing Washburn, Jun Zhou
  • Publication number: 20040230924
    Abstract: A Digital Design Method which may be automated is for obtaining timing closure in the design of large, complex, high-performance digital integrated circuits. The methodincludes the use of a tuner on random logic macros that adjusts transistor sizes in a continuous domain. To accommodate this tuning, logic gates are mapped to parameterized cells for the tuning and then back to fixed gates after the tuning. Tuning is constrained in such a way as to minimize “binning errors” when the design is mapped back to fixed cells. Further, the critical sections of the circuit are marked in order to make the optimization more effective and to fit within the problem-size constraints of the tuner. A specially formulated objective function is employed during the tuning to promote faster global timing convergence, despite possibly incorrect initial timing budgets.
    Type: Application
    Filed: May 10, 2004
    Publication date: November 18, 2004
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Patrick M. Williams, Ee K. Cho, David J. Hathaway, Mei-Ting Hsu, Lawrence K. Lange, Gregory A. Northrop, Chandramouli Visweswariah, Cindy ShuiKing Washburn, Jun Zhou