PERFORMANCE ANALYSIS AND OPTIMIZATION OF MIXED ASYNCHRONOUS SYNCHRONOUS SYSTEMS

This paper deals with the system-level performance analysis and optimi zation of a class of digital systems we call mixed asynchronous-synchr onous systems. In such a system, each computation module is either syn chronous or asynchronous, The communication among all of the modules i s assumed to be data driven, In order to adequately describe the timin g of such architectures, we introduce a graph model called MASS, which is based on several extensions of timed marked graphs, The first exte nsion is that the node set V is partitioned into synchronous and async hronous nodes. A synchronous node can only fire at ticks of its local module clock, Based on these extensions, we analyze the behavior of MA SS, in particular, period, periodicity, and maximal throughput rate. F inally, we introduce the optimization problem of assigning appropriate clock phases to synchronous nodes so to maximize the throughput rate of the resulting system. An exact solution as well as a polynomial tim e algorithm for nearly optimal phase assignment are presented.