Patents by Inventor Bradley S. Nelson

Bradley S. Nelson 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: 20070271542
    Abstract: A net of an integrated circuit design is analyzed by unfolding paths on the receive side of an asynchronous boundary to facilitate modeling of the propagation of a metastable value from a receive latch to sinks of the net. The paths are unfolded by replicating combinational logic and wiring along the coincident portions to form non-intersecting, separate paths from the receive latch to two or more sinks. Common data or control inputs are provided for the gates in the replicated combinational logic. Driver logic may additionally be inserted along each replicated path, upstream of the combinational logic, to independently drive each of the sinks.
    Type: Application
    Filed: May 19, 2006
    Publication date: November 22, 2007
    Inventors: Yee Ja, Bradley S. Nelson
  • Patent number: 7299436
    Abstract: A system and method for accurately modeling an asynchronous interface using expanded logic elements are provided. With the apparatus and method, the logic of an asynchronous interface is reduced to primitive logic elements. These primitive logic elements are expanded by the mechanisms of the present invention to take into consideration whether or not the primitive logic elements themselves may be experiencing a switching or glitch hazard and whether or not the inputs to the primitive logic elements may be based on a switching or glitch hazard from another primitive logic element in the asynchronous interface logic. These expanded logic elements are used in an integrated circuit design to replace the original primitive logic elements in the design. The asynchronous interface may then be simulated with the expanded logic elements providing outputs indicative of whether the actual data output of the expanded logic elements is deterministic or not.
    Type: Grant
    Filed: February 10, 2005
    Date of Patent: November 20, 2007
    Assignee: International Business Machines Corporation
    Inventors: Bing-Lun Chu, Yee Ja, Bradley S. Nelson, Wolfgang Roesner