About Book:

  We are very happy to witness the launch of this third edition of our work, which we are sure will be are a lot of increst amongst readers. Since the publication of the fast edition of this book in 2000, followed by its second edition in 2006, the field of microprocessors and microcontrollers has undergone phenomenal developments. The tutel microprocessor family has evolved from those early days of 4b and 8-bit microprocessors through a long evolution of 16-bit, 32-bit microprocessors to Pentium and the advanced 1-7 in addition to many variants of Pentium, Celeron and tunium The arena of multi-core processors has already begun. On the other hand, K-bit microprocessors are mostly of academic interest only, and microcontrollers are widely used for small, dedicated hardware systems and embedded applications In this background, we present a brief overview of microprocessors, starting from the basic concept of a microprocessor followed by the intermediate microprocessors, and concepts of microcontrollers and interfacing with microcontrollers

         A microprocessor is a programmable circuit that supports the execution of a set of instructions called an instruction set. Each instruction in the instruction set is represented by a predefined unique sequence of Is and Os called OPCODE (Operation Code). The data required for the execution of operation, Le operands are also expressed in Is and Os, Le binary form, and follows the epcode Customanly, the opcode and operands are specified in instructions in the form of bytes. Thus, microprocessor instruction bons consist of opcode and operand bytes. A microprocessor can execute one instruction at a time. Hence, a task to be executed by a microprocessor is expressed in terms of a sequence of instructions called a program. It is to be noted here that the microprocessor is a digital circuit and understands (accepts) the instructions or data expressed only in terms of is and Os. For convenience of entering into a microprocessor-based system, it is customarily entered byte by byte. Thus, a microprocessor system program is a sequence of bytes expressed in hexadecimal system. These programs, expressed in terms of hexadecimal bytes, are called “machine-language programs. Thus, the types of circuits, systems and machines which are able to remember the sequence of instructions, the operands related to each instruction, can execute them and finally store the result of the complete execution are called “programmable circuits or machines. These are available in the form of crude microprocessor-based systems or advanced personal computers or more savvy laptops, notebooks and palmtops

Intel Corporation has been one of the pioneers in the microprocessor industry right from its infant stage Even today, they are one of the major players in the field though many have emerged. It is thus very natural and justified to start the introduction to the field using Intel’s framework.

With the advent of the first 4-bit microprocessor 4004 from Intel Corporation in 1971, there has been a silent revolution in the domain of digital system design, which has shaken many facets of the current technological progress. In the last 40 years, the world has seen an evolution of microprocessors, whose impact on today’s technological scenario is phenomenal.

This evolution was possible because of tremendous advances in semiconductor process technology. The first microprocessor 4004 contained only around thousand transistors, while the component density increased more than threefold in less than a decade’s time. Immediately after the introduction of the 4004, Intel introduced the first 8-bit microprocessor 8008 in 1972; these processors were, however. not successful because of their inherent limitations. In 1974, Intel released the first general-purpose 8-bit microprocessor 8080. This CPU also was not functionally complete and the first 8-bit functionally complete CPU 8085 was introduced in 1977.