Towards One-pass Synthesis

The design process of digital circuits is often carried out inindividual steps, like logic synthesis, mapping, and routing. Sinceoriginally the complete process was too complex, it has been split upin several - more or less independent - phases. In thelast 40 years powerful algorithms have been developed to find optimalsolutions for each of these steps. However, the interaction of thesedifferent algorithms has not been considered for a long time. Thisleads to quality loss e.g. in cases where highly optimized netlistsfit badly onto the target architecture. Since the resulting circuitsare often far from being optimal and insufficient regarding theoptimization criteria, like area and delay, several iterations of thecomplete design process have to be carried out to get high qualityresults. This is a very time consuming and costly process.For this reason, some years ago the idea of one-pass synthesis cameup. There were two main approaches how to guarantee that a design got"first time right": So far, several approaches in these two directions have been presentedand new techniques are under development.In "Towards One-Pass Synthesis" we describe the new paradigm thatis used in one-pass synthesis and present examples for the twotechniques above. Theoretical and practical aspects are discussed andminimization algorithms are given. This will help people working withsynthesis tools and circuit design in general (in industry andacademia) to keep informed about recent developments and new trends inthis area.