ECE 15B Computer Organization

Spring 2010

Dmitri StrukovDmitri Strukov

Lecture 1: Introduction

Partially adapted from Computer Organization and Design, 4th edition, Patterson and Hennessy, and classes taught by

Patterson at Berkeley, Ryan Kastner at UCSB and Mary Jane Irwin at Penn State

Course Logistics : Instructor

Dmitri Strukov strukov@ece.ucsb.edu

Office : HFH 5153Office : HFH 5153

Office hours: Tuesday – Thursday

6:45 – 7:45 pm (right after

class) or by appointment

ECE 15B Spring 2010

MMT Simulator

• Features– Assembler & Debug

– Cycle-accurate simulation

– GUI and Script support

My Own Background...

– GUI and Script support

– Detailed statistics including

runtime conflicts

• Implementation– C - 35 K lines of code

– TCL - 7 K lines of code

ECE 15B Spring 2010

Memory latency reduction with fine-grain migrating threads in NUMA shared-memory multiprocessors” (with M. Dorojevets)

in: Proc. PDCS’02, Cambridge, MA, Nov. 2002, pp. 762-767

Course Logistics : TAs

Vivek Nandakumar vivek@ece.ucsb.edu

Office hours: Phelps 1435, Tuesday 2:00-3:00 pm (tentative)

Discussion session: Phelps 1425, Monday 5:00-5:50 pm

Isai Michel isai@umail.ucsb.edu

Office hours: Phelps 1435, Wednesday 2:00-3:00 pm

Discussion session: Phelps 1445, Friday 9:00-9:50 pm

ECE 15B Spring 2010

Course Logistics: Material

• URL

– Go to my web page www.ece.ucsb.edu/~dimastrukov/and click on ECE 15B link at the bottom

• Software: MIPS-32bit simulator (“SPIM”)• Software: MIPS-32bit simulator (“SPIM”)

– Both software and documentation available online for free

– Can be installed on any common platform

– See instructions on web for MACs

– Try to install that software early

ECE 15B Spring 2010

Course Logistics: Textbooks

• Required: Computer Organization and Design: The Hardware/Software Interface, Fourth Edition, Patterson and Hennessy (COD). The third edition is also accepted.

• Recommended: MIPS Assembly Language Programming, Robert L. Britton, 2003.Robert L. Britton, 2003.

• Additional (not required): The C Programming Language, Kernighan and Ritchie (K&R), 2nd edition

• C language manual webpage from Stanford University

• UCSB book store should have them all

ECE 15B Spring 2010

Course Logistics: Grading

• Homework Assignments (excluding HW #0):

10%

• Projects: 20%

• Quiz 1: 15%• Quiz 1: 15%

• Quiz 2: 15%

• Final: 40%

• Class Participation: 5%

– Attendance & discussion in class

ECE 15B Spring 2010

Course Logistics: Approximate

Schedule

• Approximate schedule on class syllabus

– 1 hw/project/quiz per week

– Hw/projects due Fridays at 11:00 pm in HFH, 3rd

floor (box labeled ECE15B)floor (box labeled ECE15B)

• Last year lecture viewgraphs will be replaced

with newest one on the day of lecture

• Hw, projects description, and solutions will be

posted on the web

(check website for HW#0 today)ECE 15B Spring 2010

Course Problems: Cheating

• What is cheating?– Turned-in work must be completely your own however studying

together in groups is encouraged

– Common examples of cheating: running out of time on assignment and then pick up output, take hw from box and copy, person asks to borrow solution “just to take a look”, copying and exam question etc.copying and exam question etc.

– Cheating on HWs: negative points for that assignments (e.g. if it is worth 10 points, you get -10)

– Cheating on projects/exams: At least, negative points for that project/exam. In most cases, F in the course

– Any instance of cheating will be referred to Office of Student Judicial Affairs

http://kiosk.ucsb.edu/AcademicServices/cheatingAtUCSB.aspx

ECE 15B Spring 2010

The Computer Revolution

• Progress in computer technology

– Underpinned by Moore’s Law

• Makes novel applications feasible

– Computers in automobiles– Computers in automobiles

– Cell phones

– Human genome project

– World Wide Web

– Search Engines

• Computers are pervasive

ECE 15B Spring 2010

Market size?

Semiconductor

industry >$1000B

Microprocessor (w.

embedded) > $100B

USA GDP ~ $14000B

(24% of worlds total)

The Rise of Embedded Computers

In millions

What is

next?

Population 6.4B in 2004, i.e. ~ 1PC, 2.2 cell phones, and 2.5 televisions for every 8 people

on the planet ECE 15B Spring 2010

Different Approaches to Computationcomputer engineers users

ge

ne

ral p

urp

os

e

Let’s make

circuits which will

compute anything

we want

architectureneed Computing

platform I want to

solve

equation

I want to

sort

numbers

problem

algorithmcode

ap

pli

ca

tio

n s

pe

cif

ic

problemalgorithmneed

input data

results

Computing

platform

ECE 15B Spring 2010

ap

pli

ca

tio

n s

pe

cif

icn

eu

rom

orp

hic

Let’s make

circuits which will

solve a particular

problem

I want to

denoise

my image

I want to

denoise

my image

problemalgorithmneed

Humans are better

than computers.

Let’s emulate

the brain

need architecture

I want to

predict the

future

I want to find

search for a

face on the web

training

problem

input data

results

input data

results

platform

Computing

platform

ASIC vs. FPGA vs. μP

FPGAμP

General Purpose Computing

GPU

ECE 15B Spring 2010

“Von-Neumann” Computer

Computer Keyboard,

Store –programmed concept was not invented by John von

Neumann only

Other inventors Presper Eckert

and John Mauchly ENIAC 1943University of Pensilvania

Processor

Computer

Control

Datapath

Memory

(where programs, data live whenrunning)

Devices

Input

Output

Keyboard,

Mouse

Display,

Printer

Disk(where programs, data live whennot running)

ECE 15B Spring 2010

Layers of Abstractions

I/O systemProcessor

Compiler

Operating

System

(Mac OSX)

Application (ex: browser)

Instruction SetArchitectureMemoryHardware

Software Assembler

ECE 15B Spring 2010

I/O systemProcessor

Digital Design

Circuit Design

Architecture

Datapath & Control

transistors

MemoryHardware

Computation is implemented using many layers of abstractions – WHY?

Moore’s Law

Predicts: 2X Transistors / chip every 2 years

Gordon Moore

Intel Cofounder

B.S. Cal 1950!

# o

f tr

an

sist

ors

on

an

inte

gra

ted

cir

cuit

(IC

)

B.S. Cal 1950!

Year

# o

f tr

an

sist

ors

on

an

inte

gra

ted

cir

cuit

(IC

)

en.wikipedia.org/wiki/Moore's_lawECE 15B Spring 2010

Technology Scaling Road Map (ITRS)

Year 2004 2006 2008 2010 2012

Feature size (nm) 90 65 45 32 22

Intg. Capacity (BT) 2 4 6 16 32

• Fun facts about 45nm transistors– 30 million can fit on the head of a pin

– You could fit more than 2,000 across the width of a human hair

– If car prices had fallen at the same rate as the price of a single transistor has since 1968, a new car today would cost about 1 cent

Technology Trends:

Uniprocessor Performance (SPECint)

1.52x/year

1.20x/year

Pe

rfo

rma

nce

(v

s. V

AX

-11

/78

0)

3X“Sea change” in chip design: multiple “cores” or processors per chip

• VAX : 1.25x/year 1978 to 1986• RISC + x86: 1.52x/year 1986 to 2002• RISC + x86: 1.20x/year 2002 to present

1.25x/year

Pe

rfo

rma

nce

(v

s. V

AX

ECE 15B Spring 2010

• Processor

– Speed 2x / 1.5 years (since ’85) [slowing!]

– 100X performance last decade

• Memory (DRAM)

– Capacity: 2x / 2 years (since ’96)

Kilo (103) & Kibi (210)

�

Mega (106) & Mebi (220)

�

Giga (109) & Gibi (230)

�

Tera (1012) & Tebi (240)

Computer Technology - Growth!

– 64x size last decade.

• Disk

– Capacity: 2x / 1 year (since ’97)

– 250X size last decade.

Tera (1012) & Tebi (240)

�

Peta (1015) & Pebi (250)

�

Exa (1018) & Exbi (260)

�

Zetta (1021) & Zebi (270)

�

Yotta (1024) & Yobi (280)

ECE 15B Spring 2010

AMD’s Barcelona Multicore Chip

Core 1 Core 2

51

2K

B L

2

51

2K

B L

2

2M

B s

ha

red

L3

Ca

che

� Four out-of-

order cores on one chip

� 1.9 GHz clock rate

� 65nm technology

http://www.techwarelabs.com/reviews/processors/barcelona/

Core 3 Core 4

Northbridge5

12

KB

L2

51

2K

B L

2

2M

B s

ha

red

L3

Ca

che

� 65nm technology

� Three levels of caches (L1, L2, L3) on chip

� Integrated Northbridge

ECE 15B Spring 2010

Compiler

Operating

System

(Mac OSX)

Application (ex: browser)

Instruction SetArchitectureHardware

Software Assembler

Layers of Abstraction

This class is about

this region

Need Many Layers to Handle ComplexityECE 15B Spring 2010

I/O systemProcessor

Digital Design

Circuit Design

Instruction SetArchitecture

Datapath & Control

transistors

MemoryHardware

Below the Program

Systems software

Applications software

Hardware

• System software– Operating system – supervising program that interfaces the

user’s program with the hardware (e.g., Linux, MacOS, Windows)

• Handles basic input and output operations

• Allocates storage and memory

• Provides for protected sharing among multiple applications

– Compiler – translate programs written in a high-level language (e.g., C, Java) into instructions that the hardware can execute

ECE 15B Spring 2010

Below the Program• High-level language program (in C)

swap (int v[], int k)(int temp;

temp = v[k];v[k] = v[k+1];v[k+1] = temp;

)

• Assembly language program (for MIPS)

C compiler

one-to-many

swap: sll $2, $5, 2

add $2, $4, $2lw $15, 0($2)lw $16, 4($2)sw $16, 0($2)sw $15, 4($2)jr $31

• Machine (object, binary) code (for MIPS)000000 00000 00101 0001000010000000

000000 00100 00010 0001000000100000

. . .

assembler

one-to-one

ECE 15B Spring 2010

Below the Program

lw $t0, 0($2)lw $t1, 4($2)sw $t1, 0($2)sw $t0, 4($2)

High Level Language Program (e.g., C)

Assembly Language Program (e.g.,MIPS)

Machine Language Program (MIPS)

Compiler

Assembler

temp = v[k];

v[k] = v[k+1];

v[k+1] = temp;

0000 1001 1100 0110 1010 1111 0101 1000

1010 1111 0101 1000 0000 1001 1100 0110 Program (MIPS)

Hardware Architecture Description (e.g., block diagrams)

Machine Interpretation

1010 1111 0101 1000 0000 1001 1100 0110

1100 0110 1010 1111 0101 1000 0000 1001

0101 1000 0000 1001 1100 0110 1010 1111

Logic Circuit Description(Circuit Schematic Diagrams)

Architecture Implementation

Advantages of Higher-Level Languages ?

• Higher-level languages� Allow the programmer to think in a more natural language and for

their intended use (Fortran for scientific computation, Cobol for business programming, Lisp for symbol manipulation, Java for web programming, …)

� Improve programmer productivity – more understandable code that is easier to debug and validate

� Improve program maintainability

• As a result, very little programming is done today at the assembler level

Improve program maintainability

� Allow programs to be independent of the computer on which they are developed (compilers and assemblers can translate high-level language programs to the binary instructions of any machine)

� Emergence of optimizing compilers that produce very efficient assembly code optimized for the target machine

ECE 15B Spring 2010

ECE 15B: So what’s in it for me?

• Learning computer systems from a

programmer’s point of view

– What the programmer writes

– How it is converted to something the computer – How it is converted to something the computer

understands

– How computer interprets the program

– What makes programs go slow

ECE 15B Spring 2010

ECE 15B: So what’s in it for me?

• Learn big ideas in computer engineering

– Principle of abstraction used to build systems as layers

– 5 classic components of a computer

– Data can be anything (integers, floating point, characters): program determines what it is

– Stored program concept: instructions just data

– Principle of locality, exploited via memory hierarchy

– Greater performance by exploiting parallelism

ECE 15B Spring 2010

ECE 15B: can also help you

• Assembly Language Programming– This is a skill you will pick up as a side effect of

understanding big ideas

• Hardware Design– Hardware at the abstract level with only a little bit of – Hardware at the abstract level with only a little bit of

physical implementation details to give perspective

• Understand Language Concept– If you know one, you should be able to learn another

“low” level programming language on your own

– C constructs used in many other “higher” level programming languages

ECE 15B Spring 2010

ECE 15B: Does Not Teach

• A specific assembler language

– 486 instruction set

– ARM instruction set

– PowerPC instruction set– PowerPC instruction set

• Because technologies change so dramatically

– Learning the concepts is more important that learning the language

– Learning abstract ideas is more important that learning the specific features

ECE 15B Spring 2010

Summary

• Continued rapid improvement in computing

– May end up soon but new paradigms and concept will likely inherit a lot from traditional computer implantation, e.g. multi core

– The market for computing systems is huge – The market for computing systems is huge

• Hardware/software interface is important layer in the hierarchy to understand how computing is implemented

ECE 15B Spring 2010

Questions?Questions?

ECE 15B Spring 2010