Patents by Inventor Roger K. Jackson

Roger K. Jackson 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: 4754408
    Abstract: A method of placing circuit elements in an integrated circuit. The chip area is divided into a grid. In an initial pass, the elements are randomly placed in the grid locations, and these placements are recorded. Thereafter, the elements are sequentially replaced in each of the grid locations, and a score is calculated for the wiring interconnections to the remaining elements as they were last recorded. The placement yielding the best score is recorded for that element. This placement is repeated for each of the elements. Once all the elements have been replaced, a final score is compared with the last best score. If the recent final score is better, the placements associated with that score are saved as the best placements. Then the process of replacement is repeated until a given number of iterations fails to yield a better score.
    Type: Grant
    Filed: November 21, 1985
    Date of Patent: June 28, 1988
    Assignee: International Business Machines Corporation
    Inventors: Kurt D. Carpenter, Roger K. Jackson, Keith W. Lallier
  • Patent number: 4593362
    Abstract: A wire packing method for packing wire segments in wiring bays of large-scale integrated circuit devices and integrated circuit devices produced employing such a method. Each wiring segment to be placed in a channel of a wiring bay is assigned a score in accordance with criteria developed for the particular application. The start point, end point and a segment identifier is recorded for each segment to be packed. For each channel, segments which can be considered candidates for packing in that channel are extracted from the list. For that channel, moving forwardly from one end of the channel, at the end point of each segment, a total score is calculated by adding to the score of that segment a best score occurring before the start point of the segment. If the total score exceeds a present value of a best string score for nonoverlapping segments, the present value of the best string score is replaced by the new total score, otherwise the present value of the best string score is retained.
    Type: Grant
    Filed: May 16, 1983
    Date of Patent: June 3, 1986
    Assignee: International Business Machines Corporation
    Inventors: Paul H. Bergeron, Kurt D. Carpenter, Jerome B. Hickson, Jr., Roger K. Jackson, Keith W. Lallier, Elba K. Malone