A Placement Capability Based on Partitioning

Placement is one of the numerous coordinated capabilities of the Hughes Computer-Aided Design (CAD) System. It is applicable to all of the technologies currently used to produce digital electronic assemblies and is particularly well suited to the allocation requirements of LSI and VLSI. The algorithm that is used iteratively selects sequences of module interchanges that minimize the number of signal crossings over a designated partition (line) across the assembly. An orderly succession of horizontal and vertical partitions causes a rearrangement of modules that facilitates routing, distributes wiring density and achieves minimal wirelength. The placement algorithm, its computational efficiency, its robust applicability, and the parts it plays within the Hughes CAD System are presented.