International Business Machines Corporation

Jerome B Hickson, Jr

Paul H Bergeron

Keith W Lallier

Bradford Dunham

Kurt D Carpenter

Roger K Jackson

Elba K Malone

Hirsh Lewitan

A method for interconnecting nodes in each of a number of nets. This invention involves generating initial zones for all nets and determining cumulative demand for path spaces needed by these initial zones. The demand is then compared with the supply, and scores are determined for the paths of the initial zones. Redundant paths with the worst scores are then gradually deleted until there are no redundant paths. If however, demand for path spaces still exceeds supply, expanded zones are generated in areas where demand exceeds supply and redundant paths are gradually deleted until there are no redundant paths. The paths remaining after deletion from the expanded zones are then used to interconnect the nodes of the nets. The nodes are then interconnected using the remaining paths.

Global wiring by removal of redundant paths

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. When the other end of the bay is reached, moving back towards the first end, segments are assigned to the channel for which the total score therefor exceeded the then-present value of the best string score and which do not overlap already-assigned segments.

Bay packing method and integrated circuit employing same

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Yorktown Heights, NY, United States of America

Jerome B Hickson, Jr