Classes of service for daisy chain interconnects

Abstract

We describe qHTFair, a switch scheduler that supports classes of service for networks on chips. The scheduler extends the HTFair scheduler, which is an improved version of the HyperTransport scheduling protocol. qHTFair is intended for on-chip interconnects with a daisy chain topology. With our extension, the interconnect can be divided into several classes or channels, each with its own bandwidth allocation. Bandwidth allocations are defined as ratios of channel bandwidths. Ratios can have arbitrary values and be set up dynamically.