Introduction

Working with electronic design automation (EDA) tools requires a good understanding of a multitude of terms and concepts from elementary digital electronics. The material in this chapter aims at explaining them, but makes no attempt to truly cover switching algebra or logic optimzation as gate-level synthesis is fully automated today. Readers in search of a more formal or more comprehensive treatise are referred to specialized textbooks and tutorials such as [465] [466] [25] [467] and the seminal but now somewhat dated [468]. Textbooks that address digital design more from a practical perspective include [146] [469] [470] [471].

Combinational functions are discussed in sections A.2 and A.3 with a focus on fundamental properties and on circuit organization respectively before section A.4 gives an overview on common and not so common bistable memory devices. Section A.5 is concerned with transient behavior, which then gets distilled into a few timing quantities in section A.6. At a much higher level of abstraction, section A.7 finally sums up the basic microprocessor data transfer protocols.

Common number representation schemes

Our familiar decimal number system is called a positional number system because each digit in a number contributes to the overall value with a weight that depends on its position (this was not so with the ancient Roman numbers, for instance). In a positional number system, there is a natural number B ≥ 2 that serves as a base, e.g. B = 10 for decimal and B = 2 for binary numbers.