Patents by Inventor Thomas W. Liston

Thomas W. Liston 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: 6590818
    Abstract: A method and apparatus for soft defect detection in a memory is disclosed. Bit lines are conditioned to predetermined voltages which ensure that, upon activation of the corresponding word line, all the storage transistors within the corresponding bit cells (at the intersection of the bit lines and the word line) are electrically conductive. A change in state of the bit cell in response to activation of the corresponding word line indicates the presence of a soft defect. An evaluator coupled to the memory may be used to identify defective memories by comparing the results of the testing to determine if any bit cells changed states. In one embodiment, the conditioning of the bit lines includes charging a bit line to a first predetermined voltage and its corresponding complementary bit line to a second predetermined voltage and then connecting the bit line and complementary bit line together to equalize the voltages.
    Type: Grant
    Filed: June 17, 2002
    Date of Patent: July 8, 2003
    Assignee: Motorola, Inc.
    Inventors: Thomas W. Liston, Lawrence N. Herr