Comparative analysis of resource requirements for monolithic and multi-stage Clos crosspoint switch implementations in VLSI

This paper presents an in-depth analysis of resource requirements data related to the implementation of monolithic and multi-stage (Clos) crosspoint switches in CMOS VLSI technology. A crosspoint switch is composed of two parts: a switching matrix and a configuration mechanism. Previous papers comparing the pros and cons of monolithic and multi-stage implementations only consider the difference in switching matrix resource requirements, while neglecting to scrutinize their effects on the configuration mechanism. Our approach analyzes both aspects and presents the results in symbolical and numerical terms. The results re-affirm the superiority of multi-stage implementation for switches with high numbers of inputs and outputs, but also show that for realistically-sized switches, a monolithic implementation can be more resource-efficient.