Principles and Practices of Interconnection Networks

CHAPTER 17

Router Datapath

Components

In this chapter, we explore the design of the components that comprise the datapath

of a router: the input buffer, switch, and output unit. Input buffers hold flits while

they are waiting for virtual channels, switch bandwidth, and channel bandwidth.

Input buffers may be centralized, partitioned across physical channels, or partitioned

across virtual channels.A central buffer offers the most flexibility in allocating storage

across physical channels and virtual channels, but is often impractical due to a lack of

bandwidth. Within each buffer partition, storage can be statically allocated to each

virtual channel buffer ...