Introduction to Microprocessors
Microcomputers and Microprocessors
By: John Uffenbeck
ECE @Saint Louis University, Baguio City
Prepared by: Engr. Jeffrey Des B. Binwag
• Defined as an entire central processing unit of a computer
constructed on a single piece of silicon chip.
• The microprocessor concept was developed in 1969 by INTEL
engineers Ted Hoff and Stan Mazor but its implementation was
undertaken by INTEL process engineer Federico Faggin in a chip set
that became to be known as the INTEL 4000 family.
• The INTEL 4004 version was followed by the 8 bit 8008 in 1972 and
an improved version called the 8080 in 1974.
• Similar chips to the 8080 were developed by Motorola (MC 6800)
and Zilog (Z-80). These chips had 8-bit data bus widths, and 16-bit
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1979 Issue of
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Evolution of the INTEL Microprocessors
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• An entire computer on a chip
• A microprocessor with an on-chip memory and
input/output (I/O) capability.
• Typically designed into embedded systems with a
“canned program” or a program that never changes.
• Modern microcontrollers allow reprogramming in the
field to fit specific customer requirements.
• Dataquest, a market research firm in the United States,
reports that microcontrollers outsell microprocessors
by as much as 10 to 1.
• Popular applications are in HVAC, Car controls, and
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• An electronic machine designed to perform
general to specific purpose computations
involving logical and arithmetic computations.
• A Stored-Program Computer is a computer that
executes programs that must first be saved into
the computer’s memory unit.
• PARTS OF A COMPUTER
– Central Processing Unit (CPU) or Microprocessor
– Memory Unit
– Input/ Output Devices or Peripherals
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Evolution of Computers
• Vacuum-tube Era (First Generation)
• Transistor Era (Second Generation)
• Integrated Circuit Era (Third Generation)
• Microprocessor Era
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Vacuum Tube Era
• Characterized by massive machines made up of
thousands of vacuum tubes occupying entire
rooms and requiring an air-conditioned
environment to operate reliably.
• Based on the vacuum-tube technology,
Remington Rand delivered the first Universal
Automatic Computer (UNIVAC I) in 1951.
• In 1952, International Business Machines (IBM)
came up with its Model 701 Data Processing
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• Initiated by the invention of the Bipolar Transistor in
1948 by Bell Laboratory scientists William Shockley and
John Bardeen for which they were given the Nobel
Physics Prize in 1956.
• TRADIC, the first fully transistorized computer was
invented by another Bell Laboratory team in 1954.
TRADIC produced less heat than its vacuum tube
counterpart making it more reliable and less costly.
• In 1958, IBM announced its first transistorized computer,
the 7070/7090 followed by the business oriented 1401 in
1959. These machines were built on circuit boards
mounted into rack panels and frames. Thus the term
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Integrated Circuits Era
• Spurred by the most significant invention of the 20th
century (the integrated circuit) in 1959, by Robert
Noyce of Fairchild Semiconductor Corporation and Jack
Kilby of Texas Instruments.
• Integrated circuits made it possible for all circuit
components like resistors and transistors to be
fabricated on one piece of semiconductor material.
• In 1964, IBM announced one of the most famous
computers using IC technology, the 32-bit 360 series.
This computer was known to be capable of 375,000
computations per second.
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Minicomputers and Microcomputers
• In 1965, Edson De Castro of Digital Equipment Corporation (DEC)
spearheaded the completion of the first minicomputer (or a scaled
down mainframe) costing $25,000 and called the Programmed Data
• A microcomputer is a computer whose CPU is on a single
• Today, the distinction between a minicomputer, a mainframe, and a
microcomputer is not so clear. The term supermini was also coined
for minicomputers that rival the performance of mainframes.
• Minicomputers of today are used primarily by small environments in
a time-shared environment with 50-100 users. However, with the
advent of LAN and WAN environments, even this distinction is fading.
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• Personal computers were coined in 1982 by IBM
to market a computer that featured a system
board designed around the INTEL 8088 8-bit
microprocessor, 16kB memory, and five
expansions slots that allowed third-party vendors
to supply video, printer, modem disk drives, and
RS-232 serial adapter cards.
• The IBM personal computer led to the
development of the generic PC , a computer with
interchangeable components manufactured by a
variety of companies.
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IBM Personal Computer Ad
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• A supercomputer is the most powerful computer
available at any given time.
• These machines are used to solve a complex
problem to such as the design of a supersonic
aircraft, the modeling of global climates, and the
prediction of complex financial behavior is
• The first supercomputer, the Cray-I is generally
acknowledged to have been developed by
Seymour Cray in 1976 using high-speed emitter-coupled
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• ECLs were the fastest logic circuits at the time.
• Each circuit board on the Cray-I had each circuit
board mounted on a copper heat exchanger
through which liquid Freon was circulated.
• The Cray-I consumed 128 KW of power, had a
processing speed of 130 million floating-point
operations per minute (MFLOPS), and was sold at
$ 5.1 million each.
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• Most computers are single-processor,
sequential machines that leveled off in their
performance due to the finite length of time
required for an electrical signal to propagate
through a piece of wire.
• To overcome single-processor limitations,
multiple processors were wired together via
common bus, with each processor given a
problem to solve. This was called Parallel
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• Parallel processing increased computer performance
levels from single-processors operating at MFLOPS
levels to tens of GFLOPS and even at TFLOPS levels
• Early parallel processor architecture used hypercubes
made up of an arrangement of processors in the form
of n-dimensional cubes each connected by a high-speed
• More recently, supercomputer designers have opted for
a two-dimensional rectangular mesh architecture with
multiple processors at each connecting node.
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Parallel Processor Hypercube
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RISC and CISC Processors
• Reduced Instruction Set Computers (RISCs) are
computers with a small number of instruction
sets (less than 128) as compared to Complex
Instruction Set Computers (CISCs).
• CISCs are characterized by:
– Large number of variable length instructions
– Multiple addressing modes
– Small number of internal processor registers
– Instructions require multiple clock cycles for
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• Digital Signal Processors (DSPs) are microprocessors
used to perform complex mathematical computations
on converted analog data at real time speeds.
• DSPs are different from conventional microprocessors
in the following aspects:
– Use Harvard Architecture
– Use multipliers and adders built into the processor
optimized to perform a calculation in a single cycle
– Use arithmetic pipelining
– Use DO loops to speed up repetitive operations
– Provided with multiple I/O ports for communication with
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