CENG 450 Computer Systems & Architecture

Lecture 1

Amirali Baniasadi amirali@ece.uvic.ca

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CENG 450: Computer Architecture

Instructor: Amirali Baniasadi EOW 441, Only by appt. Call or email with your schedule. Email: amirali@ece.uvic.ca Office Tel: 721-8613

Web Page for this class will be at http://www.ece.uvic.ca/~amirali/courses/ceng450.html

Text: Computer Architecture A Quantitative Approach

Filth edition,

by Patterson and Hennessy

Lecture notes will be posted on the course web page in advance.

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Course Structure

  Lectures:   1 week on Overview and Introduction (Chap 1)   2 weeks on ISA Design (Chap 2)   6 weeks on Proc. Design (Chap 3 ,4)   4 weeks on Memory and I/O (Chap 5)

  Reading assignments posted on the web for each week.   NO Homework: Problems will be posted on the web site so you

can prepare for exams/quizzes.

  Quizzes: 4 in class quizzes. Dates will be announced in advance.   Note that the above is approximate.

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Course Philosophy

  Book to be used as supplement for lectures (If a topic is not covered in the class, or a detail not presented in the class, that means I expect you to read on your own to learn those details)

  One Project (25%)   Four Quizzes (25%)- Will be announced in advance.   Final Exam(50%)

  IMPORTANT NOTE: Must get passing grade in all components to pass the course. Failing any of the three components will result in failing the course.

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Project

  Labs start at Week of Jan 23rd.

  Processor design.

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Topics

  Computer Architecture?   History   Technology   Moore’s law & Virtuous circle   Language evolution   Components of a computer   Instruction set architecture (ISA)

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How many “computers” do you have?

  Three different computing markets:

1.Desktop Computing: low-end systems, high performance workstations. Price $500 to $5000

2.Servers: web servers. Should be available and reliable. Availability: be ready if components fail. Scalability: ability to grow

3.Embedded computers: Hidden computers, ex. cell phones, washing machine, palmtop, watch… Minimize memory and power. Often not programmable.

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What is “Computer Architecture”

Computer Architecture: Behind the doors!

Computer Architecture = Instruction Set Architecture + Machine Organization + Hardware

Instruction Set Architecture: Visible to Compiler. RISC vs. CISC.

Machine Organization: Importance of Von Newman design.

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ISA

  1950s: Hardwired Control, easy to implement, limited resources   1960s: Microprogramming, more flexibility.   1970s: CISC:   Compilers in infancy so ISA designed for programmers.   Expensive & small memory: Highly encoded, Multiple size

instructions (e.g., x86 from 1-17 bytes), ISA approximates high level languages,

  1980s: RISC:   Better compiler, cheaper memory, “elemental instructions”   2000s: More resources, post-RISC?

CISC:”walk-across-the-room-without-stepping-on-the-dog” RISC:”walk-walk-walk-step over dog-walk-walk”

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History

1. “Big Iron” Computers: Used vacuum tubes, electric relays and bulk magnetic storage

devices. No microprocessors. No memory. Example: ENIAC (1945), IBM Mark 1 (1944)

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History

Von Newmann: Invented EDSAC (1949). First Stored Program Computer. Uses Memory.

Importance: We are still using the same basic design.

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Computer Components

Processor (CPU)

Memory Control

Output

Input

keyboard Mouse Disk . . .

Printer Screen

Disk . . .

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Computer Components

  Datapath of a von Newman machine

ALU

OP1 + OP2

Op1 Op2

OP1 + OP2 ...

Op1 Op2

General-purpose Registers

ALU i/p registers

ALU o/p register

Bus

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Computer Components

  Processor(CPU):   Active part of the motherboard   Performs calculations & activates devices   Gets instruction & data from memory   Components are connected via Buses

  Bus:   Collection of parallel wires   Transmits data, instructions, or control signals

  Motherboard   Physical chips for I/O connections, memory, & CPU

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Computer Components

  CPU consists of   Datapath (ALU+ Registers):   Performs arithmetic & logical operations

  Control (CU):   Controls the data path, memory, & I/O devices   Sends signals that determine operations of datapath,

memory, input & output

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Technology Change

  Technology changes rapidly   HW

  Vacuum tubes: Electron emitting devices   Transistors: On-off switches controlled by electricity   Integrated Circuits( IC/ Chips): Combines thousands of transistors   Very Large-Scale Integration( VLSI): Combines millions of transistors   What next?

  SW   Machine language: Zeros and ones   Assembly language: Mnemonics   High-Level Languages: English-like   Artificial Intelligence languages: Functions & logic predicates   Object-Oriented Programming: Objects & operations on objects

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Moore’s Prediction

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Moore’s Law:

  A new generation of memory chips is introduced every 3 years   Each new generation has 4 times as much memory as its predecessor

  Computer technology doubles every 1.5 years:

Example: DRAM capacity

K b i

t c a

p a

c i t y

Y e a r o f i n t r o d u c t i o n 1 9 9 2

1 0 0 , 0 0 0

1 0 , 0 0 0

1 0 0 0

1 0 0

1 0 1 9 9 0 1 9 8 8 1 9 8 6 1 9 8 4 1 9 8 2 1 9 8 0 1 9 7 8 1 9 7 6

1 6 M

4 M

1 M

2 5 6 K

1 6 K 6 4 K

1 9 9 4 1 9 9 6

6 4 M

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Processor Performance (SPEC)

RISC introduction

performance now improves - 50% per year (2x every 1.5 years)

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Technology => dramatic change

  Processor   logic capacity: about 30% per year   clock rate: about 20% per year

  Memory   DRAM capacity: about 60% per year (4x every 3 years)   Memory speed: about 10% per year   Cost per bit: improves about 25% per year

  Disk   capacity: about 60% per year

Question: Does every thing look OK?

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Software Evolution.

  Machine language   Assembly language   High-level languages   Subroutine libraries

  There is a large gap between what is convenient for computers & what is convenient for humans

  Translation/Interpretation is needed between both

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Language Evolution

swap (int v[], int k) { int temp temp = v[k]; v[k] = v[k+1]; v[k+1] = temp; }

0 0 0 0 0 0 0 0 1 0 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 1 1 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 1 1 1 0 0 0 0 1 1 0 0 0 0 0 1 0 0 0 0 1 1 0 0 0 1 1 0 0 0 1 1 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 1 1 0 0 1 1 1 1 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 1 0 1 0 1 1 0 0 1 1 1 1 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 1 0 1 1 0 0 0 1 1 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0

swap: muli $2, $5, 4 add $2, $4, $2 lw $15, 0($2) lw $18, 4($2) sw $18, 0($2) sw $15, 4($2) jr $31

High-level language program (in C)

Assembly language program (for MIPS)

Binary machine language program (for MIPS)

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HW - SW Components

  Hardware   Memory components

  Registers   Register file   memory   Disks

  Functional components   Adder, multiplier, dividers, . . .   Comparators   Control signals

  Software   Data

  Simple •  Characters •  Integers •  Floating-point •  Pointers

  Structured •  Arrays •  Structures ( records)

  Instructions   Data transfer   Arithmetic   Shift   Control flow   Comparison   . . .

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Things You Will Learn

  Assembly language introduction/Review

  How to analyze program performance

  How to design processor components

  How to enhance processors performance (caches, pipelines, parallel processors, multiprocessors)

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The Processor Chip

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Processor Chip Major Blocks

•  Example: Intel Pentium •  Area: 91 mm2

•  ~ 3.3 million transistors ( 1 million for cache memory)

Data cache

Control Branch

Instruction cache

Bus Integer data-path

Floating-point

datapath

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Memory

  Categories   Volatile memory

  Loses information when power is switched-off   Non-volatile memory

  Keeps information when power is switched-off   Types

  Cache:   Volatile   Fast but expensive   Smaller capacity   Placed closer to the processor

  Main memory   Volatile   Less expensive   More capacity

  Secondary memory   Nonvolatile   Low cost   Very slow   Unlimited capacity

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Input-Output (I/O)

  I/O devices have the hardest organization   Wide range of speeds

  Graphics vs. keyboard   Wide range of requirements

  Speed   Standard   Cost . . .

  Least amount of research done in this area

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Our Primary Focus

  The processor (datapath and control)   Implemented using millions of transistors   Impossible to understand by looking at each transistor   We need abstraction

  Hides lower-level details to offer simple model at higher level   Advantages

•  Intensive & thorough research into the depths •  Reveals more information •  Omits unneeded details •  Helps us cope with complexity

  Examples of abstraction: •  Language hierarchy •  Instruction set architecture (ISA)

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Instruction Set Architecture (ISA)

  Instruction set:

  Complete set of instructions used by a machine

  ISA:

  Abstract interface between the HW and lowest-level SW. It encompasses information needed to write machine-language programs including

  Instructions

  Memory size

  Registers used

  . . .

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Instruction Set Architecture (ISA)

  ISA is considered part of the SW   Several implementations for the same ISA can exist   Modern ISA’s:

  80x86/Pentium/K6, PowerPC, DEC Alpha, MIPS, SPARC, HP   We are going to study MIPS

  Advantages:   Different implementations of the same architecture   Easier to change than HW   Standardizes instructions, machine language bit patterns, etc.

  Disadvantage:   Sometimes prevents using new innovations

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Instruction Set Architecture (ISA)

Fetch Instruction From Memory

Decode Instruction determine its size & action

Fetch Operand data

Execute instruction & compute results or status

Store Result in memory

Determine Next Instruction’s address

• Instruction Execution Cycle

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What Should we Learn?

  A specific ISA (MIPS)

  Performance issues - vocabulary and motivation

  Instruction-Level Parallelism

  How to Use Pipelining to improve performance

  Exploiting Instruction-Level Parallelism w/ Software Approach

  Memory: caches and virtual memory

  I/O

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What is Expected From You?

•  Read textbook & readings! •  Be up-to-date! •  Come back with your input & questions for discussion! •  Appreciate and participate in teamwork!