Efficient escape routing for hexagonal array of high density I/Os

Abstract

The chip/package I/Os count has continuously been growing as the systems become more complicated. High density I/Os interconnection and efficient escape routing with high performance and low cost will greatly benefit the whole electronic system. We analyze the properties of the hexagonal array, which can hold about 15% more I/Os compared with the traditional square grid array. We propose three escape routing strategies for the hexagonal array: column-by-column horizontal escape routing, two-sided horizontal/vertical escape routing, and multi-direction hybrid channel escape routing. We can escape I/Os in the hexagonal array in the same or less number of routing layers compared with square grid array. The practical examples show the efficiency of our strategies. Using hexagonal array, we can reduce the number of escape routing layers as well as increase the density of I/Os.