Patents by Inventor Kathleen P. Harrington

Kathleen P. Harrington 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: 4922446
    Abstract: The invention is directed to an apparatus and method for predicting the number of bits which must be taken into account to normalize the result of a floating point addition or subtraction. The apparatus and method employ: a low precision floating point adder/subtractor, a priority encoder that determines the position of the most significant non-zero bit to generate the normalization amount and preround logic which pre-shifts a rounding bit in the opposite direction of normalization. The method and apparatus operate in parallel with a full precision floating point adder to eliminate the need for a full-precision floating point normalization calculation and rounding computation in most circumstances. The normalization amount for successful low-precision floating-point addition/subtraction is calculated by the time the full-precision floating-point addition/subtraction stage occurs.
    Type: Grant
    Filed: April 1, 1988
    Date of Patent: May 1, 1990
    Assignee: Digital Equipment Corporation
    Inventors: John H. Zurawski, Kathleen P. Harrington