System design and design automation

In this chapter we shall draw together many of the design techniques previously discussed and place then in the context of large-scale system design. The fundamental concepts underlying digital system design (partitioning circuits into data paths and controllers, constructing large circuits from replicated subcircuits, viewing a system at different levels of detail, etc.) were introduced in Chapter 1 and have been applied to many examples since. We shall now examine their role more formally and introduce the concepts of design automation and logic synthesis,in which many of the techniques for combinational and sequential circuit design are implemented as computer programs so that the application of CAD tools is extended to include the automation of the design process itself, and that (within constraints) a circuit may be implemented directly from a high-level description.