Based on slides from D. Patterson and cs152

Modified by S. J. Fritz Spring 2009 (1)

Based on slides from D. Patterson and

www-inst.eecs.berkeley.edu/~cs152/

COM 249 – Computer Organization andAssembly Language

Chapter 1 Computer Abstraction and

Technology


Where are we going??

COM 249Spring ‘09

µProc60%/yr.(2X/1.5yr)

DRAM9%/yr.(2X/10 yrs)

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Pipelining

Memory Systems

I/O

YOUR

CPU


Where Are We Going?

°Performance issues (Chapter 1) overview, vocabulary and motivation

°A specific instruction set architecture (Chapter 2)

°Arithmetic and how to build an ALU (Chapter 3)

°Constructing a processor to execute our instructions (Chapter 4)

°Pipelining to improve performance (Chapter 4)

°Memory: caches and virtual memory (Chapter 5)

°I/O (Chapter 6)

°Multicores, Multiprocessors (Chapter 7)

Key to a good grade: reading the book!


What You Will Learn°How programs are translated into

the machine language•And how the hardware executes them

°The hardware/software interface

°What determines program performance•And how it can be improved

°How hardware designers improve performance

° What parallel processing is and what implications it has for programmers


Introduction° Rapidly changing field:

•vacuum tube -> transistor -> IC -> VLSI (see section 1.3)

•doubling every 1.5 years: (Moore’s Law)memory capacity processor speed (Due to advances in technology and

organization)

° Things you’ll be learning:

•how computers work, a basic foundation

•how to analyze their performance (or how not to!)

•issues affecting modern processors (caches, pipelines)

° Why learn this stuff?

•you want to call yourself a “computer scientist”

•you want to build software people use (need performance)

•you need to make a purchasing decision or offer “expert” advice


Understanding Performance

AlgorithmDetermines number of operations executed

Programming language, compiler, architectureDetermine number of machine instructions executed per operation

Processor and memory systemDetermine how fast instructions are executed

I/O system (including OS)Determines how fast I/O operations are executed


COM 249: So what's in it for me?

•Learn some of the big ideas in CS & engineering:

•5 Classic components of a Computer•Data can be anything (integers, floating point, characters): the program determines what it is•Stored program concept: instructions just data•Principle of Locality, exploited via a memory hierarchy (cache)•Greater performance by exploiting parallelism•Principle of abstraction, used to build systems as layers•Compilation vs. interpretation through system layers•Principles/Pitfalls of Performance Measurement•Designer’s “conceptual” toolbox


“Conceptual” Tool Box?°Evaluation Techniques

°Levels of translation (e.g., Compilation)

°Levels of Interpretation (e.g., Microprogramming)

°Hierarchy (e.g, registers, cache, memory, disk, tape)

°Pipelining and Parallelism

°Indirection and Address Translation

°Synchronous /Asynchronous Control Transfer

°Timing, Clocking, and Latching

°CAD Programs, Hardware Description Languages, Simulation

°Static / Dynamic Scheduling

°Physical Building Blocks (e.g., Carry Lookahead)

°Understanding Technology Trends


Our Goals

° To understand modern computer architecture in its rapidly changing form

° To explore the relationship between hardware and software

°To design by leading you through the process of challenging design problems and by examining real designs

°To learn how to test and to design for improved performance


COM249

Where is “Computer Organization and Assembly Language”?

*Coordination of many levels of abstraction

I/O systemProcessor

CompilerOperatingSystem

(Windows 2K)

Application (Netscape)

Digital DesignCircuit Design

Instruction Set Architecture

Datapath & Control

transistors

MemoryHardware

Software Assembler


Dual Level Abstraction

SOFTWARENegation, Add,

Double, Subtract

HARDWARENegation,

Add

Higher Levels

Lower Levels


Computer ArchitectureIncludes:

°Instruction set architecture (ISA) (programmer’s abstraction of a computer)

°Organization or microarchitecture (internal implementation of a computer at the register and functional unit level)

°System architecture (organization of the computer at the cache and bus level)

°See Computing Curriculum 2001 – pages 97-101

http://www.acm.org/education/education/curric_vols/cc2001.pdf


Instruction Set Architecture (ISA)

°A very important abstraction

•interface between hardware and low-level software

•standardizes instructions, machine language bit patterns, etc.

•advantage: different implementations of the same architecture

•disadvantage: sometimes prevents using new innovations

Modern instruction set architectures:

•80x86/Pentium/K6, PowerPC, DEC Alpha, MIPS, SPARC, HP


Hardware Levels

Level 0

Level 1

Level 2 CPU, Memory, Etc.

Digital Logic Circuits

Transistors


Software Levels

High-Level Languages

Assembly Language

Operating Systems

Machine Language

Level 6

Level 5

Level 4

Level 3


Software°At higher levels (above Level 2)•Level 3: Machine language•Level 4: Operating system services

•Level 5: Assembly language•Level 6: High-level languages

° Most programs are written at Level 6.

° Hardware only understands Level 3 instructions.


Below Your Program

°Application software•Written in high-level language (HLL)

°System software•Compiler: translates HLL code to machine code

•Operating System: service code- Handling input/output

- Managing memory and storage

- Scheduling tasks & sharing resources

°Hardware•Processor, memory, I/O controllers

§1.2 Below Your

Program


Levels of Representation

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

Assembly Language Program (e.g.,MIPS)

Machine Language Program (MIPS)

Hardware Architecture Description (e.g., Verilog Language)

Compiler

Assembler

Machine Interpretation

temp = v[k];

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

v[k+1] = temp;

lw $t0, 0($2) #load word

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

#store wordsw $t0, 4($2)0000 1001 1100 0110 1010 1111 0101 1000

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 (Verilog Language)

Architecture Implementation

wire [31:0] dataBus;

regFile registers (databus);

ALU ALUBlock (inA, inB, databus);

wire w0;

XOR (w0, a, b);

AND (s, w0, a);


Revolutions

1. Agricultural

2. Industrial

3. Information / computer

Computers have become part of daily life and are ubiquitous (in cars, ATMs, microwave ovens, cell phones, etc.)

Classes: desktops, servers, supercomputers, embedded

Software: •Systems- Operating systems, compilers, assemblers

•Applications- Word processors, databases, spreadsheets, games, etc...


1/22/2008 CS152-Spring’08 2

Computing Devices Then…

EDSAC, University of Cambridge, UK, 1949


1/22/2008 CS152-Spring’08 3

Computing Devices Now

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Quic k T ime™ and aT IF F (Unc ompres s ed) dec ompres s orare needed to s ee this pic ture.

QuickTime™ and aTIFF (Uncompressed) decompressorare needed to see this picture.

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Robots

SupercomputersAutomobiles

Laptops

Set-top boxes

Games

Smart phones

Servers

Media Players

Sensor Nets

Routers

Cameras


Classes of Computers°Desktop computers

•General purpose, variety of software

•Subject to cost/performance tradeoff

°Server computers

•Network based

•High capacity, performance, reliability

•Range from small servers to building sized

°Embedded computers

•Hidden as components of systems

•Stringent power/performance/cost constraints


Embedded Computers

°Run one set of related applications, such as those in cell phones, TVs, cars, game machines, etc.

°Growth of cell phones, with embedded computers, has been faster than desktop computers.

°In 2004 there were 1 PC, 2.2 cell phones, and 2.5 TVs for every 8 people on the planet.

°In 2006, a US family owned 12 gadgets (3 TVs, 2 PCs, and others –MP3 players, cell phones, game consoles.)


The Processor Market


°Progress in computer technology•Underpinned by Moore’s Law

°Makes novel applications feasible•Computers in automobiles

•Cell phones

•Human genome project

•World Wide Web

•Search Engines

°Computers are pervasive

§1.1 IntroductionThe Computer Revolution


Moore’s Law

°Moore's Law, states that the number of transistors on a chip will double about every two years.

°Almost every measure of the capabilities of digital electronic devices is linked to Moore's law: processing speed, memory capacity, even the number and size of pixels in digital cameras

°http://en.wikipedia.org/wiki/Moore's_law

°http://www.intel.com/technology/mooreslaw/index.htm


From High Level to Low LevelAdvantages of High Level Languages

°Think in more natural terms about real world objects

°Improve programmer productivity

°Programmers independent of machine

Advantages of Low Level Language

°Faster

°Communicate directly with hardware


Components of a Computer

Same components forall kinds of computer

Desktop, server,embedded

Input/output includesUser-interface devices

Display, keyboard, mouse

Storage devicesHard disk, CD/DVD, flash

Network adaptersFor communicating with other computers

The BIG Picture


Anatomy: 5 components of any Computer

Personal Computer

Processor

Computer

Control(“brain”)

Datapath(“brawn”)

Memory

(where programs, data live whenrunning)

Devices

Input

Output

Keyboard, Mouse

Display, Printer

Disk (where programs, data live whennot running)


Anatomy of a Computer

Output device

Input device

Input device

Network cable


Anatomy of a Mouse

°Invented by Doug Englebart (1967)

°Mechanical (roller ball)

°Optical mouse•LED illuminates desktop

•Small low-res camera

•Basic image processor- Looks for x, y movement

•Buttons & wheel

°Supersedes roller-ball mechanical mouse


Through the Looking Glass

°LCD screen: picture elements (pixels)•Mirrors content of frame buffer memory


LCD Displays

°Liquid Crystal Display- thin, low power

°Uses rod shape molecules in a liquid forming a twisted helix that bends light.

°Rods straighten when current is applied and do not bend the light.

°Uses an active matrix of tiny transistors to control current and form sharper images.

°Images are composed of red, green and blue dots.


Forming Images

°An image is composed of picture elements or pixels, represented as a matrix of bits, called a bit map.

°Display matrix can be 640 x 480 to 2560 x 1600 pixels in size.

°A color display uses 8 bits for each of the 3 (RGB) colors, or 24 bits/pixel, creating millions of colors.

°A raster refresh or frame buffer is the hardware to support graphics. It stores the bit map.


Opening the Box


Inside the Processor (CPU)

°Datapath: performs operations on data

°Control: sequences datapath, memory, ...

°Cache memory•Small fast SRAM memory for immediate access to data


Inside the Processor

°AMD Barcelona: 4 processor cores


Abstractions

°Abstraction helps us deal with complexity•Hide lower-level detail

°Instruction set architecture (ISA)•The hardware/software interface

°Application binary interface (ABI)•The ISA plus system software interface

°Implementation•The details underlying and interface

The BIG Picture


A Safe Place for Data

°Volatile main memory•Loses instructions and data when power off

°Non-volatile secondary memory•Magnetic disk

•Flash memory

•Optical disk (CDROM, DVD)


Networks

°Communication and resource sharing

°Local area network (LAN): Ethernet•Within a building

°Wide area network (WAN: the Internet

°Wireless network: WiFi, Bluetooth


Technology Trends

°Electronics technology continues to evolve•Increased capacity and performance

•Reduced cost

Year Technology Relative performance/cost

1951 Vacuum tube 1

1965 Transistor 35

1975 Integrated circuit (IC) 900

1995 Very large scale IC (VLSI) 2,400,000

2005 Ultra large scale IC 6,200,000,000

DRAM capacity


Overview of Physical Implementations

°Integrated Circuits (ICs)•Combinational logic circuits, memory elements, analog interfaces.

°Printed Circuits (PC) boards•substrate for ICs and interconnection, distribution of CLK, Vdd, and GND signals, heat dissipation.

°Power Supplies•Converts line AC voltage to regulated DC low voltage levels.

°Chassis (rack, card case, ...) •holds boards, power supply, provides physical interface to user or other systems.

°Connectors and Cables.

The hardware out of which we make systems.


Review of Major Components

°Mouse ( mechanical, optical)

°Display (CRT, LCD)

°Motherboard

°Integrated Circuits (transistors, CMOS)

°CPU - controls memory, I/O, datapath according to instructions

°Datapath- performs arithmetic operations


Review of Major Components°Memory

•DRAM - Dynamic RAM - main memory

•SRAM - Static RAM- faster, more expensive

•Cache- fast buffer for main memory

•DIMM and SIMM - small boards that contain DRAM chips

•RAM, ROM, volatile, non-volatile, primary, secondary, magnetic disk, optical disks (CD, DVD), FLASH based


Memory Comparisons

°Main Memory vs. Disk

°Volatile Non Volatile

°Fast(electrical)Slower(mechanical)

°Expensive (100 * more) CheaperMemory AccessDRAM Disk

40 -80 nanoseconds 5- 15 milliseconds

10-9 10-3

(100,000 times faster)


Computer Technology - Dramatic Change!°Processor

•2X in speed every 1.5 years (since ‘85); 100X performance in last decade.

°Memory•DRAM capacity: 2x / 2 years (since ‘96); 64x size improvement in last decade.

°Disk•Capacity: 2X / 1 year (since ‘97)

•250X size in last decade.


Technology Trends: Processor Performance

0100200300400500600700800900

87 88 89 90 91 92 93 94 95 96 97

DEC Alpha 21264/600

DEC Alpha 5/500

DEC Alpha 5/300

DEC Alpha 4/266

IBM POWER 100

1.54X/yr

Intel P4 2000 MHz(Fall 2001)

We’ll talk about processor performance later on…

year

Performance measure


Technology Trends: Memory Capacity(Single-Chip DRAM)size

Year

Bit

s

1000

10000

100000

1000000

10000000

100000000

1000000000

1970 1975 1980 1985 1990 1995 2000

year size (Mbit)

1980 0.0625

1983 0.25

1986 1

1989 4

1992 16

1996 64

1998 128

2000 256

2002 512• Now 1.4X/yr, or 2X every 2 years.• 8000X since 1980!


Tech. Trends: Microprocessor Complexity

2X transistors/Chip Every 1.5 to 2.0 yearsCalled “Moore’s Law”


NetworksAdvantages

°Communication

°Resource Sharing

°Non-local access

Types

°LANs - Ethernet

°WANs


Computer Technology - Dramatic Change!

°State-of-the-art PC when you graduate: (at least…)•Processor clock speed: 5000 MegaHertz (5.0 GigaHertz)

•Memory capacity: 4000 MegaBytes (4.0 GigaBytes)

•Disk capacity: 2000 GigaBytes (2.0 TeraBytes)

•New units! Mega <= Giga, Giga <= Tera …

(Kilo, Mega, Giga, Tera, Peta, Exa, Zetta, Yotta = 1024)

Come up with a clever mnemonic, fame!


Technology in the News

°BIG•LaCie the first to offer consumer-level 1.6 Terabyte disk!

•$2,200

•Weighs 11 pounds!

°SMALL•Pretec is soon offering a 12GB CompactFlash card

•Size of a silver dollar

•Cost??

www.lacie.com/products/product.htm?

id=10129

www.engadget.com/entry/

4463693158281236/


And in conclusion...°Continued rapid improvement in

Computing•2X every 1.5 years in processor speed; every 2.0 years in memory size; every 1.0 year in disk capacity; Moore’s Law enables processor, memory (2X transistors/chip/ ~ 1.5 or 2.0 yrs)

°5 classic components of all computers Control Datapath Memory Input Output

}Processor

Documents

Based on slides from D. Patterson and cs152