ITE 272 Introduction to ITE Part II

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ITE 272 Introduction to ITEPart II

• Chapter 4
• Processor Technology and Architecture

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CPU Operation
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CPU Operation

• Two groups of actions
• Fetch Cycle (Instruction Cycle)
• Data inputs are prepared for transportation into
  data groups
• Execution Cycle
• The transformation takes place and data output is
  stored

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Fetch/Execute Cycle
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Instructions and Instruction Sets

• Instructions
• Command to the CPU to perform one of its
  primitive processing functions.
• Op Code
• The unique binary number of the instruction.
• Operand
• Groups of bits that hold the input values for the
  instruction

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Instructions and Instruction Sets
Instruction with an Op Code and two Operands
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Data Movement

• MOVE
• Copy data bits to storage locations
• LOAD
• Data transfer from main memory to register
• STORE
• Data transfer from register into primary storage

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Primitive Data Transformation Instructions
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Instructions and Instruction Sets

• The NOT instruction transforms the Boolean value
  true into false and the value false into true.
• NOT 0 1
• NOT 1 0

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Instructions and Instruction Sets

• The AND instruction generates the result true if
  both of its data inputs are true.
• 0 AND 0 0
• 1 AND 0 0
• 0 AND 1 0
• 1 AND 1 1

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Instructions and Instruction Sets

• The Inclusive OR instruction generates the value
  true if either or both data inputs are true.
• 0 OR 0 0
• 1 OR 0 1
• 0 OR 1 1
• 1 OR 1 1

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Instructions and Instruction Sets

• The Exclusive OR Instruction (XOR) generates the
  value true if either, but not both, data inputs
  are true.
• 0 XOR 0 0
• 1 XOR 0 1
• 0 XOR 1 1
• 1 XOR 1 0

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Instructions and Instruction Sets

• The ADD instruction accepts two numeric inputs
  and produces their arithmetic sum.
• 0 0 0
• 1 0 1
• 0 1 1
• 1 1 10

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Instructions and Instruction Sets

• The SHIFT instruction moves bit strings to the
  left or the right.

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Instructions and Instruction Sets

• The Logical SHIFT instruction is typically used
  to extract a single bit from a bit string.

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Instructions and Instruction Sets

• Arithmetic SHIFT
• Instruction performs multiplication or division.
• Multiplication
• Shifting one bit to the left, multiplies the
  value by 2.
• Division
• Shifting one bit to the right, divides the value
  by 2.

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Instructions and Instruction Sets
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Instructions and Instruction Sets

• Sequence Control Instructions
• Unconditional BRANCH
• Causes the processor to always depart from the
  normal sequence.
• Conditional BRANCH
• Occurs only if a specified condition is met.
• HALT
• Suspends the normal flow of instruction
  execution.

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Instruction Format
An instruction format is a template that
specifies the number of operands and the position
and length of the op code and operands.
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Instruction Format

• Fixed instruction length
• Simplify the instruction-fetching processes
  implemented with the control unit.
• Variable instruction length
• The amount by which the instruction pointer is
  incremented after the fetch is the length of the
  most recently fetched instruction

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Processor Classifications

• Reduced Instruction Set Computing (RISC)
• Absence of some complex instructions
• Avoid combined data transformation and data
  movement operations
• Fixed length instructions, short instruction
  length, and large number of general-purpose
  registers

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Processor Classifications

• Complex Instruction Set Computing (CISC)
• Developed because of limited memory and
  processing power of early computers
• Goal more work per instruction
• Result less memory required complex operations
  execute more quickly
• Subject to diminishing returns

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Processor Classifications

• CISC (Complex Instruction Set Computing)
• 28 system instructions
• 92 floating point instructions
• 52 MMX instructions
• 61 streaming media instructions
• 164 integer, logical and other instructions
• Total of 397 instructions

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Processor Classifications

• RISC (Reduced Instruction Set Computing)
• About 24 registers
• Op-code is always in same bit location / one word
  size
• More registers

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Clock Rate

• Clock Rate
• The frequency at which the system clock generates
  timing pulses.
• The rate are measured in hertz (Hz) one cycle
  per second.

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Cycle Time

• Cycle time
• Time to fetch and execute the simplest
  instruction.
• Usually NOT
• Inverse of the clock rate
• 3.00 Ghz machine would have a cycle time of about
  .0000000003 s or .3 nanoseconds

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MHz Myth

• Mhz does not equal performance
• Many variables involved
• Need method to compare systems
• MIPS (millions of instructions per second) for
  integers
• MFLOPS (millions of floating point operations per
  second)

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CPU Registers

• General-purpose
• Used to hold intermediate results or frequently
  used values in the currently executing programs.
• Special-purpose
• Instruction register
• Instruction pointer
• Program status word

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Word Size

• Word
• Unit of data that contains a fixed number of
  bytes or bits. The amount of data that a CPU
  processes at one time.
• Relationship between word size and CPU
  performance.

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Physical CPU

• Switches and Gates
• The basic building blocks of computer processing
  circuits are electrical gates.
• Basic processing functions on binary digits are
  performed with the logical functions (AND, OR,
  XOR, and NOT)

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Physical CPU
NOT
AND
OR
XOR
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Physical CPU

• More complex processing functions require more
  complicated arrangements of gates.
• A full-adder and half-address can be formed using
  the basic gates.

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Physical CPU
Half Adder
Full Adder
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Physical CPU

• Heat
• The negative effects of heat on electrical
  conductivity are damage to the conductor and
  changes in the inherent resistance of the
  conductor.
• Heat Sink
• An object specifically designed to absorb heat
  and rapidly dissipate it using air or water
  movement.

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Physical CPU
Heat Sink
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Processor Fabrication

• Transistors and Integrated Circuits
• Transistors are made of semiconductor material
  that has been treated with chemical impurities to
  enhance the semiconducting effects.
• Integrated Circuit
• Implements several transistors and their
  interconnections on a single chip.

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Physical CPU

• Microchips and Microprocessors
• A microprocessor is a microchip that contains all
  of the circuits and connections that implement a
  CPU.

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Physical CPU
Memory chip containing 330 million transistors
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Physical CPU

• Moores Law
• Observed that the rate of increase in transistor
  density on microchips had increased steadily,
  roughly doubling every 18 to 24 months.

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Physical CPU
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The End