Expanded rectangles: a new VLSI data structure

A data structure derived from corner stitching which allows efficient representation of VLSI layouts is presented. While each entry in the expanded rectangle database is larger than the corresponding corner-stitched entry, generally fewer entries are required to represent the same VLSI layout. The data structure has two important features: first, the VLSI design is represented as a slicing structure in which each slice contains a portion of the solid material; and second, corner stitches are used to provide two-dimensional nearness information. Initial measurements indicate that expanded rectangles is a viable data structure for use in a complete VLSI layout system.<>