Optimal aspect ratios of building blocks in VLSI

Abstract

The building blocks in a given floorplan may have several possible physical implementations yielding different layouts. This paper discusses the problem of selecting an optimal implementation for each building block so that the area of the final layout is minimized. A polynomial algorithm that solves this problem for slicing floorplans was presented elsewhere, and it has been proved that for general (non-slicing) floorplans the problem is NP-complete. We suggest a branch and bound algorithm which proves to be very efficient and can handle successfully large general non-slicing floorplans. We show also how the non-slicing and the slicing algorithms can be combined to handle efficiently very large general floorplans.