Low Propagation Delay Load-Balanced 4$\,\times\,$4 Switch Fabric IC in 0.13-$\mu{\rm m}$ CMOS Technology

Abstract

A load-balanced Birkhoff-von Neumann (LB-BvN) 4 × 4 switch fabric IC is proposed for feedback-based switch systems. This is fabricated in 0.13- μm CMOS technology and the chip area is 1.380 × 1.080 mm2. The overall data rate of the LB-BvN 4 × 4 switch fabric IC is up to 32 Gb/s (8 Gb/s/channel) with only 0.8 ns propagation delay. The LB-BvN switch is highly recommended for constructing the next-generation terabit switch. In a feedback-based switch system, the long propagation delay of the switch module reduces the system throughput significantly. In this paper, we present a scalable LB-BvN 4 × 4 switch fabric IC directly in the high-speed domain. By observing the deterministic switching pattern of the N×N LB-BvN switch, we present a low-complexity pattern generator that reduces the PG complexity from O(N3) to O(1). This technique reduces the propagation delay of the switch module from 30 to 0.8 ns, and also provides 80% area saving and 85% power saving compared to serializer-deserializer interfaces. The proposed LB-BvN 4 × 4 switch fabric IC is suitable for feedback-based switch systems to solve the throughput degradation problem.