Computer Architecture Lecture Notes Spring 2005 Dr. Michael P. Frank

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Computer Architecture Lecture Notes Spring
2005Dr. Michael P. Frank

• Competency Area 1
• Computer System Components
• Lecture 2

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ENIAC - background

• Electronic Numerical Integrator And Computer
• Eckert and Mauchly
• University of Pennsylvania
• Proposed to develop a computer for the
  calculation of Trajectory tables for weapons
  during WWII (Army Ballistics Research Laboratory)
• Started 1943
• Finished 1946
• Too late for war effort
• Used to help determine feasibility of H-bomb
• Used until 1955

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ENIAC - details

• Decimal (not binary)
• Its memory contained 20 accumulators of 10
  digits.
• 10 vacuum tubes represented each digit.
• Programmed manually by switches
• 18,000 vacuum tubes
• 30 tons
• 1500 square feet
• 140 kW power consumption
• 5,000 additions per second

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von Neumann/Turing

• Stored Program concept
• Main memory storing programs and data
• Turing Machine (Alan Turing) Given enough
  memory and sufficient time the general purpose
  computer can compute all functions that are
  computable.
• ALU operating on binary data
• Control unit interpreting instructions from
  memory and executing
• Input and output equipment operated by control
  unit
• Princeton Institute for Advanced Studies
• IAS Computer (major components in a computer
  system)
• Foundation for general-purpose computer
• Completed 1952

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Picture of the IAS Computer
Smithsonian Image 95-06151
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Structure of von Neumann machine
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IAS - details

• 1000 x 40 bit words
• 1000 storage locations of 40-bit words
• Binary number
• 2 x 20 bit instructions
• Set of registers (storage in CPU)
• Memory Buffer Register (MBR)
• Memory Address Register (MAR)
• Instruction Register (IR)
• Instruction Buffer Register (IBR)
• Program Counter (PC)
• Accumulator (AC)
• Multiplier Quotient (MQ)

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Structure of IAS detail
MBR Contains a word to be stored In memory, or is
used to receive a Word from memory.
MAR Specifies the address in memory of the word
to be written from or into MBR
IR Contains the 8-bit opcode instruction being
executed
IBR Temporarily holds the right hand instruction
from a word in memory
PC Contains the address of the next instruction
pair to be fetched from memory
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IAS - details

• The IAS computer had 21 instructions which are
  grouped as follows
• Data Transfer Moves data between memory and ALU
  registers or between two ALU registers
• Unconditional Branch Changes the sequence of
  instructions to execute repetitive operations
• Conditional Branch The branch can be made
  dependent on a condition, thus, allowing decision
  points.
• Arithmetic Operations performed by the ALU
• Address /modify Permits addresses to be
  computed in the ALU and then inserted into
  instructions stored in memory.

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Commercial Computers

• 1947 Eckert-Mauchly developed their own
  Computer Corporation
• UNIVAC I (Universal Automatic Computer)
• Designed to perform mainly scientific
  calculations (e.g. US Bureau of Census 1950
  calculations)
• Became part of Sperry-Rand Corporation
• Late 1950s - UNIVAC II
• Faster
• More memory

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IBM

• Punched-card processing equipment
• 1953 - the 701
• IBMs first stored program computer
• Scientific calculations
• 1955 - the 702
• Business applications
• Lead to 700/7000 series

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Transistors

• The second generation of technology Transistors
  replaced vacuum tubes
• Smaller
• Cheaper
• Less heat dissipation
• Solid State device
• Made from Silicon (Sand)
• Invented 1947 at Bell Labs
• William Shockley et al.
• Discrete components

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Transistor Based Computers

• Second generation machines
• More complex arithmetic and logic units
• Incorporated the use of high-level programming
  languages
• Also used system software with machines (e.g.
  operating systems)
• NCR RCA produced small transistor machines
• IBM 7000 Series
• Digital Equipment Corporation (DEC) - 1957
• Produced PDP-1 which began the minicomputer
  phenomenon

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Transistors
Computer Generations
Generation Approximate Dates Technology Typical Speed (ops/sec)
1 1946-1957 Vacuum Tubes 40,000
2 1958-1964 Transistor 200,000
3 1965-1971 Small and medium scale integration 1,000,000
4 1972-1977 Large-scale integration (LSI) 10,000,000
5 1978- Very LSI 100,000,000
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Microelectronics

• Up to this point, computers were manufactured
  using discrete components which was becoming more
  expensive and cumbersome as computers continued
  to improve in performance.
• Microelectronics dominated the next generation of
  computers.
• Literally - small electronics
• A computer is made up of gates, memory cells and
  interconnections
• These can be manufactured on a semiconductor
• e.g. silicon wafer

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Generations of Computer

• Vacuum tube - 1946-1957
• Transistor - 1958-1964
• Small scale integration - 1965 on
• Up to 100 devices on a chip
• Medium scale integration - to 1971
• 100-3,000 devices on a chip
• Large scale integration - 1971-1977
• 3,000 - 100,000 devices on a chip
• Very large scale integration - 1978 to date
• 100,000 - 100,000,000 devices on a chip
• Ultra large scale integration
• Over 100,000,000 devices on a chip

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Moores Law

• As microelectronics grew in the computer
  industry, an increase in the density of
  components on chip became evident.
• Gordon Moore - cofounder of Intel
• Gordons Observation Number of transistors on a
  chip will double every year.
• Since 1970s development has slowed a little
• Number of transistors doubles every 18 months
• Cost of a chip has remained almost unchanged
• Higher packing density means shorter electrical
  paths, giving higher performance
• Smaller size gives increased flexibility
• Reduced power and cooling requirements
• Fewer interconnections increases reliability

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Moores Law

• Formal Consequences of Moores Law
• Cost of chip has remained relatively stable
  during a period of rapid growth in density. This
  implies the cost of computer logic and memory
  circuitry has fallen at a drastic rate.
• Because logic and memory elements are placed
  closer together on more densely packed chips, the
  electrical path length is shortened, increasing
  operating speeds.
• The computer becomes smaller, making it more
  convenient to placed in a variety of
  environments.
• There is a reduction in power and cooling
  requirements.
• The interconnections on the integrated circuit
  are much more reliable than solder connections.
  With more circuitry on each chip, there are fewer
  interchip connections.

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Growth in CPU Transistor Count
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IBM 360 series

• Introduced in 1964
• Replaced ( not compatible with) 7000 series
• First planned family of computers
• Similar or identical instruction sets
• Similar or identical O/S
• Increasing speed
• Increasing number of I/O ports (i.e. more
  terminals)
• Increased memory size
• Increased cost
• Multiplexed switch structure
• The introduction of this family cemented IBM as a
  world leader in computer manufacturing industry.

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Picture of IBM 360
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DEC PDP-8

• Also introduced in 1964
• First minicomputer
• Did not need room w. A/C
• Small, could sit on a lab bench
• Relatively cheap 16,000
• Compared to 100k for IBM 360
• Embedded applications Original Equipment
  Manufacturers (OEM) allowed users to buy PDP-8
  machines and integrate them into a total system
  for resale.
• BUS STRUCTURE

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DEC - PDP-8 Bus Structure

• Highly flexible
• All systems share a common set of signal paths
• Allows other modules to be plugged into the bus
• to create various configurations

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Intel

• 1971 - 4004
• First microprocessor
• Whole CPU on a single chip
• 4 bit
• Followed in 1972 by 8008
• 8 bit
• Both for specific applications
• 1974 - 8080
• Intels first general purpose microprocessor

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Speeding it up

• Pipelining
• On board cache
• On board L1 L2 cache
• Branch prediction
• Data flow analysis
• Speculative execution

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Pentium Evolution (1)

• 8080
• first general purpose microprocessor
• 8 bit data path
• Used in first personal computer Altair
• 8086
• much more powerful
• 16 bit
• instruction cache, prefetch few instructions
• 8088 (8 bit external bus) used in first IBM PC
• 80286
• 16 Mbyte memory addressable
• up from 1Mb
• 80386
• 32 bit
• Support for multitasking

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Performance
1970s Processors
4004 8008 8080 8086 8088
Introduced 1971 1972 1974 1978 1979
Clock Speeds 108 KHz 108 KHz 2 MHz 5 MHz, 8MHz, 10MHz 5 MHz, 8MHz
Bus Width 4 bits 8 bits 8 bits 16 bits 8 bits
Number of Transistors 2300 3500 6000 29,000 29,000
Addressable Memory 640 bytes 16 KBytes 64 KBytes 1 MB 1 MB
Virtual Memory -- -- -- -- --
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Performance
1980s Processors
80286 386TM DX 386TM SX 486TM DX CPU
Introduced 1982 1985 1988 1989
Clock Speeds 6 MHz 12.5 MHz 16 MHz-33 MHz 16 MHz-33 MHz 25 MHz- 50 MHz
Bus Width 16 bits 32 bits 16 bits 32 bits
Number of Transistors 134,000 275,000 275,000 1.2 million
Addressable Memory 16 MB 4 GB 4GB 4GB
Virtual Memory 1 GB 64 TB 64 TB 64 TB
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Performance
1990s Processors
486TM SX Pentium Pentium Pentium II
Introduced 1991 1993 1995 1997
Clock Speeds 16 MHz-133MHz 60 MHz 166 MHz 150 MHz-200MHz 200 MHz-300MHz
Bus Width 32 bits 32 bits 64 bits 64 bits
Number of Transistors 1.185 million 3.1 million 5.5 million 7.5 million
Addressable Memory 4 GB 4 GB 64 GB 64 GB
Virtual Memory 64 TB 64TB 64 TB 64 TB
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Performance
Recent Processors
Pentium III Pentium 4
Introduced 1999 2000
Clock Speeds 450 MHz 1.3-1.8 GHz
Bus Width 64 bits 64 bits
Number of Transistors 95 million 42 million
Addressable Memory 64 GB 64 GB
Virtual Memory 64 GB 64 TB
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Performance Mismatch

• Processor speed increased
• Memory capacity increased
• Memory speed lags behind processor speed!!

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DRAM and Processor Characteristics
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Pentium Evolution (2)

• 80486
• sophisticated powerful cache and instruction
  pipelining
• built in maths co-processor
• Pentium
• Superscalar
• Multiple instructions executed in parallel
• Pentium Pro
• Increased superscalar organization
• Aggressive register renaming
• branch prediction
• data flow analysis
• speculative execution

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Pentium Evolution (3)

• Pentium II
• MMX technology
• graphics, video audio processing
• Pentium III
• Additional floating point instructions for 3D
  graphics
• Pentium 4
• Note Arabic rather than Roman numerals
• Further floating point and multimedia
  enhancements
• Itanium
• 64 bit
• See Intel web pages for detailed information on
  processors

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Intel Itanium 2 (McKinley)

• 64b Processor
• 221 million transistors! (US adult
  population)
• How are they used?
• What will we do as transistor counts
  continue to grow?
• Most of chip is used for memories, inst.
  decoding, dynamic scheduling
• Why is it done this way?
• How much more efficient could it be if more
  of area went to actual processing?

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Even More Recent Example

• Runs 64-bit IA-64 ISA
• Die 3.74 cm2
• .13µ process
• 410M transistors
• 1.5GHz core
• 1.3V logic
• 130W powerconsumption!
• 6.4GB/s bus
• Cost 2,247- 4,226
• 9MB L3 cache later this year

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Internet Resources

• http//www.williamstallings.com
• Computer Organization and Architecture
• http//www.intel.com/
• Search for the Intel Museum
• http//www.ibm.com
• http//www.dec.com
• Charles Babbage Institute
• PowerPC
• Intel Developer Home