Microprocessors and Micro controllers
objectives
On successful completion of this chapter, you will be able to:
• List the differences between microcontrollers and microprocessors.
• Describe the prominant standard features of a typical microcontroller.
• Name several contemporary microcontroller manufacturers and notable features of their products.
• Identify the major components of a microcontroller development system.
Introduction
The past three decades have seen the introduction of a technology that has radically changed the way in which we analyze and control the world around us. Born of parallel developments in computer architecture and integrated circuit fabrication, the microprocessor, or "computer on a chip," first became a commercial reality in 1971 with the introduction of the 4-bit 4004 by a small, unknown company by the name of Intel Corporation. Other, more well-established, semiconductor firms soon followed Intel’s pioneering technology so that by the late 1970s we could choose from a half dozen or so microprocessor types.
The 1970s also saw the growth of the number at personal computer users from a handful of hobbyists and "hackers" to millions of business, industrial, governmental, defense, educational, and private users now enjoying the advantages of inexpensive computing.
A by-product of microprocessor development was the microcontroller. The same fabrication techniques and programming concepts that make possible the general-purpose microprocessor also yielded the microcontroller.
Microcontrollers are not as well known to the general public, or to many in the technical community, as are the more glamorous microprocessors. The public is, however, very well aware that "something" is responsible for all of the smart VCRs, clock radios, washers and dryers, video games, telephones, microwaves, TVs, automobiles, toys, vending machines, copiers, elevators, irons, and a myriad of other articles that are intelligent and "programmable." Companies are also aware that being competitive in this age of the microchip requires their products, or the machinery they use to make those products, to have some "smarts."
The purpose of this chapter is to introduce the concept of a microcontroller and survey a representative group. The remainder of the book will study one of the most popular types, the 8051, in detail.