Evolution of the Microprocessor

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Evolution of Microprocessors

Title


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Group Members


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EVOLUTION OF THE MICROPROCESSOR

INTRODUCTION

Definition:

A microprocessor, sometimes called a logic chip, or most of, thecentral processing unit (CPU) functions. Basically A microprocessor isdesigned to perform all arithmetic and logic operations with

appropriate manner
http://searchcio-midmarket.techtarget.com/sDefinition/0,,sid183_gci213867,00.htmlhttp://searchcio-midmarket.techtarget.com/sDefinition/0,,sid183_gci213867,00.html


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INTRODUCTION

In the mid-seventies, a microprocessor was defined as acentral processing unit (CPU) realized on a LSI(large-scaleintegration) chip, operating at a clock frequency of 1 to 5MHz and constituting an 8-bit system

It was a single component having the ability to perform awide variety of different functions.

Because of their relatively low cost and small size, themicroprocessors permitted the use of digital computers inmany areas

Many non-technical people associate microprocessors with

only PCs yet there are thousands of appliances that have amicroprocessor embedded in them telephone, dishwasher,microwave, clock radio, etc.

In these items, the microprocessor acts primarily as acontroller and may not be known to the user.


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The Breakthrough in Microprocessors

The switching units in computers that were used

in the early 1940s were the mechanical relays

In 1950s, the vacuum tubes took over. The

Atanasoff-Berry Computer (ABC) used vacuumtubes as its switching units rather than relays.

Then came the transistor which was

acknowledged as a revolutionary development.which was the result of a series of developments

in the applications of physics.


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Cont

The transistor changed the computer from agiant electronic brain to a commodity like a TVset.

This innovation was awarded to three scientists:John Bardeen, Walter ,Brattain, and WilliamShockley.

As a result of the technological breakthrough of

transistors, the introduction of minicomputersand the personal computer revolution was madepossible.


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Cont

The terminology, integrated circuits or ICs..

Initially, the demand for ICs was typically the

military and aerospace

industries which were great users of

computers and who were the only industries

that could afford computers


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The term microprocessor first came into

use at Intel in 1972

A microprocessor was nothing more than an

extension of the arithmetic and logic IC chips

doing more functions into one chip.

Today, the term still refers to an LSI single-

chip processor capable of carrying out many

of the basic operations of a digital computer.


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What led to the development of

microprocessors?

(1) Digital computer technology

(2) Semiconductors

(3) The calculator industry


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How a microprocessor works

Based on the instructions, a microprocessor doesthree basic things:

A. Using its ALU (Arithmetic/Logic Unit), a

microprocessor can perform mathematicaloperations like addition, subtraction,multiplication and division.

B. A microprocessor can move data from one

memory location to another.C. A microprocessor can make decisions and jump

to a new set of instructions based on thosedecisions.


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Archictecture of a microprocessor

A brief view of the Architecture of microprocessor

an address bus (that may be 8, 16 or 32 bits wide)that sends an address to memory;

a data bus (that may be 8, 16 or 32 bits wide) that cansend data to memory or receive data from memory;

a RD (Read) and WR (Write) line to tell the memorywhether it wants to set or get the addressed location;

a clock line that lets a clock pulse sequence theprocessor;


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Cont..

a reset line that resets the program counter

to zero (or whatever) and restarts execution.

The connection of the microprocessors to

other unitsmemory and I/O devicesis

done with the Address, Data, and control

buses


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Generation of microprocessors

Microprocessors were categorized into fivegenerations: first, second, third,fourth, and fifthgenerations. Their characteristics are described below:

First-generation: The microprocessors that were introduced in 1971 to

1972 were referred to as the first generation systems.First-generation microprocessors processed theirinstructions seriallythey fetched the instruction,decoded it, then executed it.

When an instruction was completed, themicroprocessor updated the instruction pointer andfetched the next instruction, performing thissequential drill for each instruction in turn.


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cont..

Second generation By the late 1970s (specifically 1973), enough transistors

were available on the IC to usher in the secondgeneration of microprocessor sophistication

This generation is defined by overlapped fetch, decode,and execute steps. As the first instruction is processedin the execution unit, the

second instruction is decoded and the third instructionis fetched.

The distinction between the first and second generationdevices was primarily the use of newer semiconductortechnology to fabricate the chips.

This new technology resulted in a five-fold increase in

instruction, execution, speed, and higher chip densities.


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cont.

Third generation

The third generation, introduced in 1978, was represented by Intels 8086

The third generation came about as IC transistor counts approached

250,000.

This generation of microprocessors was different from the previous ones in

that all major workstation manufacturers began developing their ownRISC-based microprocessor

architectures.

Fourth generation

As the workstation companies converted from commercial microprocessors

to in-house designs,

microprocessors entered their fourth generation with designs surpassing a

million transistors, helping to issue and retire more than one instruction

per clock cycle


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Cont..

Fifth generation

Microprocessors in their fifth generation, employed

decoupled super scalar processing, and their design

soon surpassed 10 million transistors.

In this generation, PCs are a low-margin, high-

volume-business dominated by a single

Microprocessor.


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Companies associated

with microprocessors

Overall, Intel Corporation

dominated the

microprocessor area even

though other companies

like

Texas Instruments,

Motorola, etc

also introduced some

microprocessors.


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Microprocessors Today

Technology has been changing at a rapid pace. Everyday anew product is made to make life a little easier. Thecomputer plays a major role in the lives of most people.

It allows a person to do practically anything. The Internetenables the user to gain more knowledge at a much fasterpace compared to researching through books.

The portion of the computer that allows it to do morework than a simple computer is the microprocessor.

Microprocessor has brought electronics into a new era

and caused component manufacturers and end-users torethink the role of the computer.


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Cont

From their humble beginnings 25 years ago,microprocessors have proliferated into an astoundingrange of chips, powering devices ranging from telephonesto supercomputers .

Today, microprocessors for personal computers getwidespread attentionand have enabled Intel to becomethe world's largest semiconductor maker.

The impact of the microprocessor, however, goes fardeeper than new and improved products.

It is altering the structure of our society by changing howwe gather and use information, how we communicatewith one another, and how and where we work.


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Where is the industry of

microprocessors going?

Almost immediately after their introduction,

microprocessors became the heart of the

personal computer. Since then, the

improvements have come at an amazingpace.

The competition to determine who has

produced the fastest and smallest


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Where is the industry of

microprocessors going?

chips will climb to more than 10GHz from

today's 1GHz standard by the year 2011.

However, researchers are paying increasing

attention to software. That's because new

generations of software, especially

computing-intensive user interfaces, will call

for processors with expanded capabilities andperformance.


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Evolution of the Microprocessor

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