A constraints programming approach to communication scheduling on SoPC architectures

ABSTRACT

This paper presents a novel approach to scheduling communications among concurrent hardware processes mapped onto a "System on a Programmable Chip." Point-to-point, broadcast and multi-cast ommunication types are supported. The algorithm has been prototyped on the Processor-Coupled Polymorphous Fabric for the Altera Excalibur Arm architecture. The communication schedule problem has been specified using Constraints Programming. The advantages of our method are the following: Application of a general constraint solver makes it possible to express many different sorts of constraints in a uniform manner. All imposed constraints are handled by the solver concurrently which increases the chances of obtaining optimal results. The scheduler guarantees that loops periods are the same for each iteration so the smaller controllers can be generated. The method has been illustrated with a Fabric-based implementation of the K-means clustering algorithm for which an optimal communication schedule has been achieved.