Chapter 1

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Computer Organization

Course Web Sitehttp://www.engr.uconn.edu/~ibrahim/hardware

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Textbooks

Computer Organization, 5th ed. Carl Hamacher, Zvonko Vranesic, Safwat

Zaky

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Processor

Computer Functional Units

Memory

Arithmetic& Logic

Control

I/O

Input

Output

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Course Organization

Computer Structure (Ch 1) Instruction Sets & Addressing Modes (Ch 2) Control Unit Design (Ch 7)

Computer Arithmetic (Ch 6) Memory (Ch 5) Input/Output (Ch 4) Pipelining (Ch 8) Embedded Systems (Ch 9)

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Computer Information (Binary)

(Machine) Instructions (Machine Language) Programs

Data 2's complement BCD ASCII

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Output Display Printer Speakers

I/O

Input Keyboard Mouse Microphone Camera Scanner

Serial Communications Network Modem

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Memory

Primary Random Access

Memory (RAM) Read Only

Memory (ROM)

Organization Word Address Read/Write

Secondary Magnetic

Disks Tape

Optical Disks

Hierarchy Cache Main Virtual

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ALU

Arithmetic Addition Subtraction Multiplication Division Comparison

Logic AND OR NOT XOR

Registers Store Shift

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Control Unit

Coordinates/Directs other Units

Computer Operation Input

Program/Data stored in Memory Processing

Information fetched into RegistersProcessed by ALU

Output

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History

First Generation (miliseconds) von Neumann (stored program) Vacuum Tubes Magnetic Core Memory Teletypes/Magnetic Tapes

Second Generation (microseconds) Transistor High-level Languages (Fortran)

Compilers I/O Processors

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History

Third Generation Integrated Circuits Microprogramming Parallelism/Pipelining Operating Systems (sharing) Cache/VM

Fourth Generation (nanoseconds) VLSI (Single Chip Microprocessor) Personal Computers Networks

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Processor

Computer Functional Units

Memory

Arithmetic& Logic

Control

I/O

Input

Output

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MAR - Memory Address Register

MDR - Memory Data Register

PC - Program Counter

IR - Instruction Register

Control Unit

Arithmetic Logic Unit

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Computer Instructions

Assembly Language

MOVE NUM1,R1

MOVE #1,R2

ADD #1,R1

ADD R1,R2

Register Transfer Notation

R1 [NUM1]

R2 1

R1 1 + [R1]

R2 [R1] + [R2]

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The “fetch-execute cycle”

Fetch the instruction whose address is in the program counter

Increment the PC so it holds the address of the next instruction

Execute the instruction just fetched Fetch the next instruction Etc.

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Arithmetic/Logic Unit

Memory

Control Unit

Instruction Register

Program CounterData Register

Data Register

instruction

instruction fetch

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Memory

CPU

Bus

MAR MDR

instruction address

instruction

PC IR

Memory Control

Instruction Fetch

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Arithmetic/Logic Unit

Memory

Control Unit

Instruction Register

Program CounterData Register

Data Register

data

instruction execute

data

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Memory

CPU

Bus

MAR MDR

operand (data) address

data

IR R1

Memory Control

Instruction Execution

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Example Instruction

Fetch MAR [PC] PC [PC] + 1 MDR [MEM([MAR])] IR [MDR]

Execute MAR NUM1 MDR [MEM([MAR])] R1 [MDR]

MOVE NUM1,R1

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Another Example

Fetch MAR [PC] PC [PC] + 1 MDR [MEM([MAR])] IR [MDR]

Execute R1 1 + [R1]

ADD #1,R1

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Single-Bus Structure

Memory ProcessorInput Output

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System Software

Compiler High-level Language Machine Language

Assembler Assembly Language Machine Language

Text Editor Keyboard Input File

Operating System Control Sharing & Interaction Assign & Manage Resources

Memory Disk Space

Handle I/O

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Memory Performance

MainMemory

ProcessorCacheMemory

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Processor Clock

Period (P)

Rate (R)

CLK

R = 1/P

1 GHz = 1/1ns

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Performance Equation

Processor Execution Time (T) Number of Machine Language Instructions (N) Average Steps per Machine Instruction (S) Clock Rate (R)

MIPS: Millions of instructions per second Megaflops: Millions of floating point operations per second Megahertz: Millions of clock cycles per second

T N S

R

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Pipelining

F1 E1

I1

F2 E2

I2

F3 E3

I3

Sequential Execution

F1 E1I1

F2 E2I2

F3 E3I3

Pipelined Execution

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Parallel Processing

Parallel Execution Superscalar

Multiprocessors Shared-Memory

Multicomputers Message-Passing

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Multiprocessing, multitasking.

A system that provides for concurrent execution

of multiple programs, i.e., manages multiple processes

Programs share use of the processor (take turns).

Multiprogramming

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1) Multiprogramming

2) Parallel processing (multiple

processors)

Multiprocessing:

Multitasking:

1) Multiprogramming

2) A particular form of multiprogramming

depending on context

depending on context

Multiprogramming

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Figure 1.4. User program and OS routine sharing of the processor.

Printer

Disk

Program

routinesOS

Timet 0 t 1 t 2 t 3 t 4 t 5

Figure 1.4. User program and OS routine sharing of the processor.

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CISC vs RISC

Complex Instruction Set Computers (CISC) Smaller N Larger S

Reduced Instruction Set Computers (RISC) Larger N Smaller S Easier to Pipeline