CENG 450 Computer Systems

1
CENG 450Computer Systems ArchitectureLectur
e 1

• Amirali Baniasadi
• amirali_at_ece.uvic.ca

2
CENG 450 Computer Architecture

• Instructor
• Amirali Baniasadi
• EOW 441, Only by appt. Call or
  email with your schedule.
• Email amirali_at_ece.uvic.ca
  Office Tel [phone]
• Web Page for this class will be
  at
• http//www.ece.uvic.ca/amirali/c
  ourses/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.

3
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.

4
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.

5
Project

• Labs start at Week of Jan 23rd.
• Processor design.

6
Topics

• Computer Architecture?
• History
• Technology
• Moores law Virtuous circle
• Language evolution
• Components of a computer
• Instruction set architecture (ISA)

7
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.
8
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.

9
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?
• CISCwalk-across-the-room-without-stepping-on-the
  -dog
• RISCwalk-walk-walk-step over dog-walk-walk

10
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)

11
History

• Von Newmann
• Invented EDSAC (1949).
• First Stored Program Computer.
• Uses Memory.
• Importance We are still using the same basic
  design.

12
Computer Components
Memory
Processor (CPU)
Printer Screen Disk . . .
Output
Control
keyboard Mouse Disk . . .
Input
13
Computer Components

• Datapath of a von Newman machine

OP1 OP2 ... Op1 Op2
General-purpose Registers
ALU i/p registers
Op1
Op2
Bus
ALU
ALU o/p register
OP1 OP2
14
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

15
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

16
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

17
Moores Prediction
18
Moores 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

19
Processor Performance (SPEC)
performance now improves 50 per year (2x every
1.5 years)
RISC introduction
20
Technology gt 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?

21
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

22
Language Evolution
swap (int v, int k) int temp temp
vk vk vk1 vk1 temp

High-level language program (in C)
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
Assembly language program (for MIPS)
Binary machine language program (for MIPS)
23
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

24
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)

25
The Processor Chip
26
Processor Chip Major Blocks

• Example Intel Pentium
• Area 91 mm2
• 3.3 million transistors ( 1 million for cache
  memory)

27
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

28
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

29
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)

30
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
• . . .

31
Instruction Set Architecture (ISA)

• ISA is considered part of the SW
• Several implementations for the same ISA can
  exist
• Modern ISAs
• 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

32
Instruction Set Architecture (ISA)

• Instruction Execution Cycle

33
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

34
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!