SSBD: A Single Side Buffered Deflection Router Achieving Competitive Performance Relative To Conventional Buffered Router

Abstract

As technology scaling drives the no.of processors upward, current on-chip routers consume substantial portions of chip area, performance, cost & power budgets. Recent work proposes to apply well-known routing technique, which eliminate buffers & hence buffers power (static & dynamic) at the cost of some misrouting or deflection called bufferless deflection routing. While bufferless NoC design has shown promising area and power reductions and offers similar performance to conventional buffered for many workloads. Such design provides lower throughput, unnecessary networkhops and wasting  power at high network loads.

To address this issue we propose an innovative NoC router design called Single Side Buffered Defection (SSBD)router. Compared to previous bufferless deflection  router SSBD contributes (i) a router microarchitecture with a double-width ejection path and enhanced arbitration with in-router prioritization. (ii)small side buffers to hold some traffic that would have otherwise been deflected.