An optimal clock period selection method based on slack minimization criteria

Abstract

An important decision in synthesizing a hardware implementation from a behavioral description is selecting the clock period to schedule the datapath operations into control steps. Prior to scheduling, most existing behavioral synthesis systems either require the designer to specify the clock period explicitly or require that the delays of the operators used in the design be specified in multiples of the clock period. An unfavorable choice of clock period could result in operations being idle for a large portion of the clock period and, consequently, affect the performance of the synthesized design. In this article, we demonstrate the effect of clock slack on the performance of designs and present an algorithm to find a slack-minimal clock period. We prove the optimality of our method and apply it to several examples to demonstrate its effectiveness in maximizing design performance.