Microprocessor 1

Prolegomena - Calculation and Storage Functions - Models of Computation and Computer Architecture

Philippe Darche

• Publisher: Wiley-ISTE
• Year: 2020
• Print ISBN: 9781786305633
• eBook ISBN: 9781119779643
• Edition: 1
• Topic: Computer Science
• Subtopic: Computer Engineering
• Index: Computer Science

Since its commercialization in 1971, the microprocessor, a modern and integrated form of the central processing unit, has continuously broken records in terms of its integrated functions, computing power, low costs and energy saving status. Today, it is present in almost all electronic devices. Sound knowledge of its internal mechanisms and programming is essential for electronics and computer engineers to understand and master computer operations and advanced programming concepts.

This book in five volumes focuses more particularly on the first two generations of microprocessors, those that handle 4- and 8- bit integers. Microprocessor 1 – the first of five volumes – presents the computation function, recalls the memory function and clarifies the concepts of computational models and architecture. A comprehensive approach is used, with examples drawn from current and past technologies that illustrate theoretical concepts, making them accessible.

1
The Function of Computation

As in music theory, we cannot discuss the microprocessor without positioning it in the context of the history of the computer, since this component is the integrated version of the central unit. Its internal mechanisms are the same as those of supercomputers, mainframe computers and minicomputers. Thanks to advances in microelectronics, additional functionality has been integrated with each generation in order to speed up internal operations. A computer¹ is a hardware and software system responsible for the automatic processing of information, managed by a stored program. To accomplish this task, the computer’s essential function is the transformation of data using computation, but two other functions are also essential. Namely, these are storing and transferring information (i.e. communication). In some industrial fields, control is a fourth function. This chapter focuses on the requirements that led to the invention of tools and calculating machines to arrive at the modern version of the computer that we know today. The technological aspect is then addressed. Some chronological references are given. Then several classification criteria are proposed. The analog computer, which is then described, was an alternative to the digital version. Finally, the relationship between hardware and software and the evolution of integration and its limits are addressed.

NOTE.– This chapter does not attempt to replace a historical study. It gives only a few key dates and technical benchmarks to understand the technological evolution of the field.

1.1. Beginnings

Humans have needed to count since our earliest days (Ifrah 1994; Goldstein 1999). Fingers were undoubtedly used as the first natural counting tool, which later led to the use of the decimal number base. During archeological excavations, we have also found notched counting sticks, bones and pieces of wood. The incised bones of Ishango, dated between 23,000 and 25,000 years BC, provide an example (Figure 1.1).

Figure 1.1. Ishango’s incised bones. For a color version of this figure, see www.iste.co.uk/darche/microprocessor1.zip

(source: unknown)

Counting sticks were used during antiquity, as well as pebbles, hence the word calculus, from the Latin calculus which means “small pebble”. Knotted ropes were also used for counting, an example being the Incan quipu (Figure 1.2). This Incan technique (dating ≈ 1200–1570) used a positional numbering system (cf. § 1.2 of Darche (2000)) in base-10 (Ascher 1983).

Figure 1.2. A quipu. For a color version of this figure, see www.iste.co.uk/darche/microprocessor1.zip

(source: unknown)

The need for fast and precise computation necessitated the use of computing instruments. Two exemplars are the abacus and the slide rule. The abacus is a planar calculating instrument, with examples including the Roman (Figure 1.3(a)) and the Chinese (Figure 1.3(b)) abacus. The latter makes it possible to calculate the four basic arithmetic operations by the movements of beads (or balls) strung on rods, which represent numbers.

Figure 1.3. Roman abacus (a) between the 2nd and 5th Centuries (© Inria/AMISA/Photo J.-M. Ramès); Chinese abacus (b). For a color version of this figure, see www.iste.co.uk/darche/microprocessor1.zip

The 17th Century saw the introduction of mechanical computing machines, and the beginning of the history of computers is generally dated from their appearance. They met the need to systematically calculate tables of nu...

Table of contents

• Cover
• Table of Contents
• Title page
• Copyright
• Quotation
• Preface
• Introduction
• 1 The Function of Computation
• 2 The Function of Memory
• 3 Computation Model and Architecture: Illustration with the von Neumann Approach
• Conclusion of Volume 1
• Exercises
• Acronyms
• References
• Index
• End User License Agreemen