Transcript Microprocessor

Introduction to
Microprocessors
From: Wikipedia, the free
encyclopedia
Microprocessor
• A microprocessor incorporates most or all of the
functions of a central processing unit (CPU) on a single
integrated circuit (IC). [1]
• The first microprocessors emerged in the early 1970s
and were used for electronic calculators, using BCD
arithmetics on 4-bit words.
• Other embedded uses of 4 and 8-bit microprocessors,
such as terminals, printers, various kinds of automation
etc, followed rather quickly.
• Affordable 8-bit microprocessors with 16-bit
addressing also led to the first general purpose
microcomputers in the mid-1970s.
Microprocessor
• Die of an Intel 80486DX2 microprocessor
(actual size: 12×6.75 mm) in its packaging
Central processing unit
• A central processing unit (CPU), or sometimes just called
processor, is a description of a class of logic machines that
can execute computer programs.
• This broad definition can easily be applied to many early
computers that existed long before the term "CPU" ever
came into widespread usage. However, the term itself and
its initialism have been in use in the computer industry at
least since the early 1960s (Weik 1961).
• The form, design and implementation of CPUs have
changed dramatically since the earliest examples, but their
fundamental operation has remained much the same.
Central processing unit
• Early CPUs were custom-designed as a part of a larger, usually oneof-a-kind, computer. However, this costly method of designing
custom CPUs for a particular application has largely given way to
the development of mass-produced processors that are suited for
one or many purposes.
• This standardization trend generally began in the era of discrete
transistor mainframes and minicomputers and has rapidly
accelerated with the popularization of the integrated circuit (IC).
• The IC has allowed increasingly complex CPUs to be designed and
manufactured in very small spaces (on the order of millimeters).
Both the miniaturization and standardization of CPUs have
increased the presence of these digital devices in modern life far
beyond the limited application of dedicated computing machines.
Modern microprocessors appear in everything from automobiles to
cell phones to children's toys.
Central processing unit
• Prior to the advent of machines that resemble today's
CPUs, computers such as the ENIAC had to be
physically rewired in order to perform different tasks.
• These machines are often referred to as "fixedprogram computers," since they had to be physically
reconfigured in order to run a different program.
• Since the term "CPU" is generally defined as a software
(computer program) execution device, the earliest
devices that could rightly be called CPUs came with the
advent of the stored-program computer.
... like being inside the computer
slartmagazine.com
EDVAC, one of the first electronic stored program computers.
ENIAC
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The idea of a stored-program computer was already present during ENIAC's
design, but was initially omitted so the machine could be finished sooner. On June
30, 1945, before ENIAC was even completed, mathematician John von Neumann
distributed the paper entitled "First Draft of a Report on the EDVAC."
It outlined the design of a stored-program computer that would eventually be
completed in August 1949 (von Neumann 1945). EDVAC was designed to perform
a certain number of instructions (or operations) of various types. These
instructions could be combined to create useful programs for the EDVAC to run.
Significantly, the programs written for EDVAC were stored in high-speed computer
memory rather than specified by the physical wiring of the computer. This
overcame a severe limitation of ENIAC, which was the large amount of time and
effort it took to reconfigure the computer to perform a new task.
With von Neumann's design, the program, or software, that EDVAC ran could be
changed simply by changing the contents of the computer's memory.[1]
ENIAC
• ENIAC, short for Electronic Numerical Integrator And Computer,[1] was
the first general-purpose electronic computer. Precisely, it was the first
high-speed, purely electronic, Turing-complete, digital computer capable
of being reprogrammed to solve a full range of computing problems,[2]
since earlier machines had been built with some of these properties.
ENIAC was designed and built to calculate artillery firing tables for the U.S.
Army's Ballistic Research Laboratory.
• The contract was signed on June 5, 1943 and Project PX was constructed
by the University of Pennsylvania's Moore School of Electrical Engineering
from July, 1943. It was unveiled on February 14, 1946 at Penn, having cost
almost $500,000. ENIAC was shut down on November 9, 1946 for a
refurbishment and a memory upgrade, and was transferred to Aberdeen
Proving Ground, Maryland in 1947. There, on July 29 of that year, it was
turned on and would be in continuous operation until 11:45 p.m. on
October 2, 1955.
Glen Beck (background) and Betty Snyder
(foreground) program the ENIAC in BRL
building 328. (U.S. Army photo)
Programmers Betty
Jean Jennings (left)
and Fran Bilas
(right) operate the
ENIAC's main
control panel at the
Moore School of
Electrical
Engineering. (U.S.
Army photo from the
archives of the ARL
Technical Library)
Cpl. Irwin Goldstein (foreground) sets the switches on one of the
ENIAC's function tables at the Moore School of Electrical
Engineering. (U.S. Army photo)
Microprocessor
• Processors were for a long period constructed out of small
and medium-scale ICs containing the equivalent of a few to
a few hundred transistors.
• The integration of the whole CPU onto a single VLSI chip
therefore greatly reduced the cost of processing capacity.
• From their humble beginnings, continued increases in
microprocessor capacity has rendered other forms of
computers almost completely obsolete (see history of
computing hardware), with one or more microprocessor as
processing element in everything from the smallest
embedded systems and handheld devices to the largest
mainframes and super computers.
Microprocessor
• Three projects
arguably delivered a
complete
microprocessor at
about the same time,
namely Intel's 4004,
the Texas Instruments
(TI) TMS 1000, and
Garrett AiResearch's
Central Air Data
Computer (CADC).
The 4004 with cover removed (left) and as
actually used (right).
ARCHITECTURES
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8-bit designs
16-bit designs
32-bit designs
64-bit designs in personal computers
Multicore designs
RISC
Special-purpose designs
– microcontrollers, digital signal processors (DSP) and
graphics processing units (GPU).
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65xx
– MOS Technology 6502
– Western Design Center 65xx
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ARM family
Altera Nios, Nios II
Atmel AVR architecture (purely microcontrollers)
EISC
RCA 1802 (aka RCA COSMAC, CDP1802)
DEC Alpha
Intel
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4004, 4040
8080, 8085
8048, 8051
iAPX 432
i860, i960
Itanium
LatticeMico32
M32R architecture
MIPS architecture
Motorola
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Motorola 6800
Motorola 6809
Motorola 68000 family, ColdFire
[[MotoG4, G5
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NSC 320xx
OpenCores OpenRISC architecture
PA-RISC family
National Semiconductor SC/MP ("scamp")
Signetics 2650
SPARC
SuperH family
Transmeta Crusoe, Efficeon (VLIW architectures, IA-32 32-bit Intel x86 emulator)
INMOS Transputer
x86 architecture
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Intel 8086, 8088, 80186, 80188 (16-bit real mode-only x86 architecture)
Intel 80286 (16-bit real mode and protected mode x86 architecture)
IA-32 32-bit x86 architecture
x86-64 64-bit x86 architecture
XAP processor from Cambridge Consultants
Xilinx
– MicroBlaze soft processor
– PowerPC405 embedded hard processor in Virtex FPGAs
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Zilog
– Z80, Z180, eZ80
– Z8, eZ8
– and others