Microprocessor 4: Core Concepts - Software Aspects (Computer Engineering)

The fourth volume deals with the software aspects of this component. The main characteristics of the Instruction Set Architecture (ISA) of a generic component are detailed. We then study the two ways to alter the execution flow with both classic and interrupt function call mechanisms. This volume details how to program a microprocessor in five chapters. The first two chapters demonstrate the three characteristics of ISA (Instruction Set Architecture, cf. § Vl-3.5). which are: instruction encoding, addressing modes and the instruction set of a generic component. Then, additional notions linked to the instruction set and execution are discussed in the third chapter. This primarily involves the notion of illegal, invalid, reserved and trusted instructions, the notion of memory alignment, orthogonality and the symmetry of the instruction set. as well as the notion of pme, re-entrant and relocatable code. Then, the subjects of execution time, memory requirements, execution modes, portability and virtualization will be discussed. Finally, it ends with aspects that are very important in industry, their hardware and software compatibilities, how to measure execution performances and the criteria for choosing a microprocessor or MPU (Microprocessor Unit). The last two chapters study two ways of altering execution flow. These are the concepts of the sub-program and interruption. 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 4 – the fourth of five volumes – addresses the software aspects of this component. Coding of an instruction, addressing modes and the main features of the Instruction Set Architecture (ISA) of a generic component are presented. Futhermore, two approaches are discussed for altering the flow of execution using mechanisms of subprogram and interrupt. A comprehensive approach is used, with examples drawn from current and past technologies that illustrate theoretical concepts, making them accessible.