8051 microcontrollers

Development Systems for Microcontrollers What is needed to be able to apply a microcontroller to your product? That is, what package of hardware and software will allow the microcontroller to be programmed and connected to your application? A package commonly called a development system is required. First, trained personnel must be available either on your technical staff or as consultants. One person who is versed in digital hardware and compute^ software is the minimum number. Second, a device capable of programming EPROMs must be available to -test the prototype device. Many of the microcontroller families discussed have a ROMless version, an EPROM version, or an electrically erasable and program­mable read only memory (EEPROM) version that lets the designer debug the hardware and software prototype before committing to full-scale production; Many inexpensive EPROM programmers are sold that plug into a slot of most" popular personal computers. More expensive, and more ...

A Microcontroller Survey Markets for microcontrollers can run into millions of units per applica­tion. At these volumes the microcontroller is a commodity item and must be optimized so that cost is at a minimum. Semiconductor manufacturers have produced a mind-numbing array of designs that would seem to meet almost any need. Some of the chips listed in this section are no longer in regular pro­duction, most are current, and a few are best termed "smokeware": the dreams of an aggressive marketing department. Four-Bit Microcontrollers In a commodity chip, expense is represented more by the volume of the package and the number of pins it has than the amount of silicon inside. To minimize pin count and package size, it is necessary that the basic data word-bit count be held to a minimum, while still enabling useful intelligence to be implemented. Although 4 bits, in this era of 64-bit "maximicros," may seem somewhat ludicrous, we must recall that the original ...

The Z80 and the 8051 To see the differences in concept between a microprocessor and a micro­controller, in the following table we will examine the pin configurations, archi­tecture, and instruction sets for a 1980s-era 8-bit microprocessor, the Zilog Z80, and a microcontroller, the 8-bit Intel 8051: Note that the point here is not to show that one design is "better" than the other,- the two designs are intended to be used for different purposes and in dif­ferent ways. For example, the Z80 has a very rich instruction set. The penalty that is paid for this abundance is the number of multi-byte instructions needed, some 71% of the total number. Each byte of a multi-byte instruction must be fetched from program memory, and each fetch takes time ; this results in longer program byte counts and slower execution time versus single-byte in­structions. The 8051 has a 62% multi-byte instruction content; the 8051 pro­gram is more compact and will run faster to accomplish simila...

Microprocessors and Microcontrollers Readers who have no prior concepts of computer operation should read Chapter 4 now. Microprocessors and microcontrollers stem from the same basic idea, are made by the same people, and are sold to the same types of system designers and programmers. What is the difference between the two? Microprocessors A microprocessor, as the term has come to be known, is a general-purpose digital computer central processing unit (CPU). Although popularly known as a "computer on a chip," the microprocessor is in no sense a complete digital computer. Figure .1 shows a block diagram of a microprocessor CPU, which contains an arithmetic and logic unit (ALU), a program counter (PC), a stack pointer (SP), some working registers, a clock timing circuit, and interrupt circuits. To make a complete microcomputer, one must add memory, usually read­ only program memory (ROM] and random-access data memory (RAM], mem­ory decoders, an oscillator, and a num...

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 ...