ABSTRACT
The main components of a switch are the buffers, the crossbar, and the routing logic as well as the switch and virtual-channel (VC) allocator. In this chapter we explore the various alternatives for the logic-level implementation of these components and discuss pros and cons of each available option. A single optimum solution does not exist for any of the main switch components and the designer is responsible for selecting the appropriate solution that best fits the area-delay-energy constraints of the specific switch implementation. In any case, a complete design space exploration is required that examines at the same time the various architectural-level solutions analyzed in Chapter 2 along with their implementation complexity. We hope that this chapter acts as
Era
crossbar
Buffers
Switch AllocatorRouting
Buffers
Downstream Flow Control
Upstream Flow Control
LC
LC
LC
LC
Buffers
Buffers
FIGURE 3.1: The main parts of the switch. This chapters deals with the implementation of the highlighted components: the buffers, the crossbar, and the switch/VC allocator.
