Principles and Practices of Interconnection Networks

CHAPTER 19

Allocation

While an arbiter assigns a single resource to one of a group of requesters, an allocator

performs a matching between a group of resources and a group of requesters, each

of which may request one or more of the resources. Consider, for example, a set

of router input units, each of which holds several flits destined for different output

ports of a switch. We have already been introduced to allocators in Section 17.2.2,

where we discussed their use to allocate crossbar switches. On each cycle, a switch

allocator must perform a matching between the input units and the output ports so

that at most one flit from each input port is selected ...