Dataflow Model for Credit-Controlled Static-Priority Arbitration

A Credit-Controlled Static Priority (CCSP) arbiter has been proposed that circumvents two key downsides of alternative arbiters in real-time embedded systems. The first is that it enables a better resource utilization by decoupling essential properties, such as allocated rate, allocation granularity and latency. Secondly, it has a fast and small hardware implementation whose correctness is formally proved. However, the existing dataflow model of the arbiter, which is based on the general model for a class of latency-rate (LR) servers, does not capture bursty provided service. As a result, system-level analysis of CCSP leads to unnecessarily large resource allocation to satisfy application requirements. In this document, we present a new dataflow model to address this drawback. The new dataflow model is based on a piecewise linear service guarantee that accurately models the provided service by CCSP. As a result of the new dataflow model, a given resource under CCSP arbitration can support more requestors, or a given set of requestors can be accommodated with less resource.