Module placement on BSG-structure and IC layout applications

Abstract

A new method of packing the rectangles (modules) is presented with applications to IC layout design. It is based on the bounded-sliceline grid (BSG) structure. The BSG dissects the plane into rooms associated with binary relations ``right-to''and ``above'' such that any two rooms are uniquely in either relation. A packing is obtained through an assignment of modules on the BSG, followed by physical realization BSG-PACK. A simulated annealing searches for a good packing of all packings by changing the assignments. Experiments showed that hundreds of rectangles are easily packed in a small rectangle area (chip) with a quite good quality in area efficiency. A wide adaptability is demonstrated specific to IC layout design. Remarkable examples are: the chip is not necessarily rectangle, L-shaped modules and modules which are allowed to partially overlap each other can be handled.