1. COM 249 – Computer Organization and Assembly Language Chapter 1 Computer Abstraction and Technology
Greet class
Based on slides from D. Patterson and
www-inst.eecs.berkeley.edu/~cs152/

2. COM 249 Spring ‘09 Where are we going?? Arithmetic Single/multicycle
Datapaths
µProc
60%/yr.
(2X/1.5yr)
DRAM
9%/yr.
(2X/10 yrs) 1 10
100
1000
1980
1981
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
CPU
1982
Processor-Memory
Performance Gap: (grows 50% / year)
Performance
Time
“Moore’s Law”
COM 249
Spring ‘09
IFetch
Dcd
Exec
Mem WB
Pipelining Y O U R C P
Memory Systems
I/O

3. 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!

4. How programs are translated into the machine language
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

5. 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

6. Understanding Performance
Algorithm
Determines number of operations executed
Programming language, compiler, architecture
Determine number of machine instructions executed per operation
Processor and memory system
Determine how fast instructions are executed
I/O system (including OS)
Determines how fast I/O operations are executed

7. 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

8. “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

9. 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

10. Where is “Computer Organization and Assembly Language”?
Application (Netscape)
Operating
Compiler
System
(Windows 2K)
Software
Assembler
Instruction Set
Architecture
Hardware
Processor
Memory
I/O system
Datapath & Control
Digital Design
COM249
Circuit Design
transistors
Coordination of many levels of abstraction

11. Dual Level Abstraction
SOFTWARE
Negation, Add,
Double, Subtract
Higher Levels
HARDWARE
Negation,
Add
Lower Levels
CHANGED

12. Computer Architecture
Includes:
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
01.pdf

13. 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

14. Hardware Levels CPU, Memory, Etc. Level 2 Digital Logic Circuits
Transistors
Level 0

15. Software Levels High-Level Languages Level 6 Assembly Language Level 5
Operating Systems
Level 4
Machine Language
Level 3

16. At higher levels (above Level 2)
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.
CHANGED

17. Morgan Kaufmann Publishers
April 23, 2018
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
Chapter 1 — Computer Abstractions and Technology

18. Levels of Representation
temp = v[k];
v[k] = v[k+1];
v[k+1] = temp;
High Level Language Program (e.g., C)
Compiler
lw $t0, 0($2) #load word
lw $t1, 4($2)
sw $t1, 0($2) #store word
sw $t0, 4($2)
Assembly Language Program (e.g.,MIPS)
Assembler
Machine Language Program (MIPS)
Machine Interpretation
wire [31:0] dataBus;
regFile registers (databus);
ALU ALUBlock (inA, inB, databus);
Hardware Architecture Description (e.g., Verilog Language)
Architecture Implementation
wire w0;
XOR (w0, a, b);
AND (s, w0, a);
Logic Circuit Description (Verilog Language)

19. 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...

22. 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

23. 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.)

24. Morgan Kaufmann Publishers
April 23, 2018
The Processor Market
Chapter 1 — Computer Abstractions and Technology

25. The Computer Revolution
§1.1 Introduction
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

26. 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

27. From High Level to Low Level
Advantages 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

28. Components of a Computer
Same components for all kinds of computer
Desktop, server, embedded
Input/output includes
User-interface devices
Display, keyboard, mouse
Storage devices
Hard disk, CD/DVD, flash
Network adapters
For communicating with other computers
The BIG Picture

29. Anatomy: 5 components of any Computer
Personal Computer
Keyboard, Mouse
Computer
Processor
Memory
(where
programs,
data
live when
running)
Devices
Disk (where
programs,
data
live when
not running)
Control
(“brain”)
Input
That is, any computer, no matter how primitive or advance, can be divided into five parts:
1. The input devices bring the data from the outside world into the computer.
2. These data are kept in the computer’s memory until ...
3. The datapath request and process them.
4. The operation of the datapath is controlled by the computer’s controller.
All the work done by the computer will NOT do us any good unless we can get the data back to the outside world.
5. Getting the data back to the outside world is the job of the output devices.
The most COMMON way to connect these 5 components together is to use a network of busses.
Datapath
(“brawn”)
Output
Display, Printer

30. Anatomy of a Computer Output device Network cable Input device

31. 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

32. Through the Looking Glass
LCD screen: picture elements (pixels)
Mirrors content of frame buffer memory

33. 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.

34. 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 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.

35. Opening the Box

36. Inside the Processor (CPU)
Datapath: performs operations on data
Control: sequences datapath, memory, ...
Cache memory
Small fast SRAM memory for immediate access to data

37. Inside the Processor
AMD Barcelona: 4 processor cores

38. Morgan Kaufmann Publishers
April 23, 2018
Abstractions
The BIG Picture
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
Chapter 1 — Computer Abstractions and Technology

39. Morgan Kaufmann Publishers
April 23, 2018
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)
Chapter 1 — Computer Abstractions and Technology

40. Morgan Kaufmann Publishers
April 23, 2018
Networks
Communication and resource sharing
Local area network (LAN): Ethernet
Within a building
Wide area network (WAN: the Internet
Wireless network: WiFi, Bluetooth
Chapter 1 — Computer Abstractions and Technology

41. Morgan Kaufmann Publishers
April 23, 2018
Technology Trends
Electronics technology continues to evolve
Increased capacity and performance
Reduced cost
DRAM capacity
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
Chapter 1 — Computer Abstractions and Technology

42. Overview of Physical Implementations
The hardware out of which we make systems.
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.

43. 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

44. 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

45. Memory Comparisons Main Memory vs. Disk Memory Access
Volatile Non Volatile
Fast(electrical) Slower(mechanical)
Expensive (100 * more) Cheaper
Memory Access
DRAM Disk
nanoseconds milliseconds
(100,000 times faster)

46. 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.

47. Technology Trends: Processor Performance
Intel P MHz
(Fall 2001)
1.54X/yr
Performance measure
year
We’ll talk about processor performance later on…

48. Technology Trends: Memory Capacity (Single-Chip DRAM)
year size (Mbit)
1986 1
1989 4
Now 1.4X/yr, or 2X every 2 years.
8000X since 1980!

49. Tech. Trends: Microprocessor Complexity
2X transistors/Chip Every 1.5 to 2.0 years
Called “Moore’s Law”

50. Networks Advantages Types Communication Resource Sharing
Non-local access
Types
LANs - Ethernet
WANs

51. Computer Technology - Dramatic Change!
State-of-the-art PC when you graduate: (at least…)
Processor clock speed: MegaHertz (5.0 GigaHertz)
Memory capacity: 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!

52. Technology in the News BIG SMALL
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??

53. } Processor 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