Principles and Practices of Interconnection Networks

CHAPTER 16

Router Architecture

A router is composed of registers, switches, function units, and control logic that

collectively implement the routing and flow control functions required to buffer and

forward flits en route to their destinations. Although many router organizations exist,

in this chapter, we examine the architecture of a typical virtual-channel router and

look at the issues and tradeoffs involved in router design.

Modern routers are pipelined at the flit level. Head flits proceed through pipeline

stages that perform routing and virtual channel allocation and all flits pass through

switch allocation and switch traversal stages. Pipeline stalls ...