Comments on “Minimizing Buffer Requirements Under Rate-Optimal Schedule in Regular Dataflow Networks”

Abstract

In this paper we propose a new approach that allows one to argue and discuss the results achieved so far by [7], which investigate the minimizing buffer requirements under rate-optimal schedule in Regular Dataflow Networks. Our methodology is devoted to the construction of static schedules for Digital Signal Processing Systems presented by Synchronous Dataflows (SDF) with different rates (known as Multi Rate Dataflows) and to foreseen the total amount of buffer memory of SDFs along with per arc space allocation. In [6], Govindarajan et al. call this type of dataflows Regular Stream Flow Graphs to highlight the nature of the token flow in the arcs. The mapping proposed in [11] can be seen as a natural bridge between the two domains (Petri nets and Dataflows) in investigating the buffer memory requirements, moreover one can also measure the activity duration’s on the Petri net side. The limited resource of a system is a natural issue and the claim for their availability during system’s activity must be foreseen to preclude exhaustion of resources. Therefore this occurrence inhibits system evolution and blocks it. The paper is divided in four topics. After a summarized overview of the supporting formalisms being investigated by the authors (dataflows and Petri nets), Section 2.2. addresses the main topics behind the mapping bridge outlined between dataflows and Petri nets, followed by a summarized overview of the tools and computational environments used to develop and simulate the resulting Petri net models. In Section 3, the discussion and results achieved so far are point out and used to identify misjudgment concerning the total buffer requirement for a schedule in Synchronous Dataflows. And finally in Section 4. conclusions are highlighted to emphasize the added contribution about the foreseen memory requirements for SDFs using the proposed approach by Rocha et al. [11].