Invisible edge and soft tied in compaction strategy

Maidee, Pongstorn; Choomchuay, Somsak

Invisible edge and soft tied in compaction strategy

Author(s)

Maidee, Pongstorn

Choomchuay, Somsak

Date Issued

December 1, 1998

Type

Article

Abstract

In most conventional one-dimensional compaction technique, the objects frequently tied together to reduce the computation complexity. The compactness of the resulting layout may, however, be reduced when the tied appear in the critical path. In this paper, this problem is solved by the soft tied which can be broken to relocate the objects position. The compactness is also limited by the extra edge used to avoid diagonal constraint violation. In addition, the wire ended without any rigid object at its end can cause an additional vertex in the constraint graph. The number of this wire gradually increase after jog insertion performed in each compaction step, thus the complexity will be increased. The invisible edge is proposed to solve this problem. Furthermore, any necessary jogs can be inserted automatically. The invisible edge and soft tied technique allows the one-dimensional compaction to gain the compactivity close to that obtained by the two-dimensional compaction within reasonable time complexity O(N²).

Citation

IEEE Asia Pacific Conference on Circuits and Systems Proceedings, 133-136, 1998