Computer Organization and Design David. Paterson and John L. Hennessy

Outlile (1)Computer Abstractions and Technology (第一週) (2)Instructions：Language of the computer (第二、三週) (3)Arithmetic for computer (第四、五週) (4)Assessing and understanding performance (第六、七週) (5)The processor：Datapath and Control (第八、九週) (6)Enhancing performance with pipelining (第十、十一週) (7)Large and Fast：Exploiting memory Hierarchy (第十二、十三週) (8)Storage, Network, and other peripherals (第十四、十五週)

Chapter 1

Introduction This course is all about how computers work But what do we mean by a computer? Different types: desktop, servers, embedded devices Different uses: automobiles, graphics, finance, genomics… Different manufacturers: Intel, Apple, IBM, Microsoft, Sun… Different underlying technologies and different costs! Analogy: Consider a course on “automotive vehicles” Many similarities from vehicle to vehicle (e.g., wheels) Huge differences from vehicle to vehicle (e.g., gas vs. electric) Best way to learn: Focus on a specific instance and learn how it works While learning general principles and historical perspectives

FIGURE 1.1 The number of distinct processors sold between 1998 and 2002

FIGURE 1.2 Sales of microprocessors between 1998 and 2002 by instruction set architecture combining all uses.

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 Both Hardware and Software affect performance: Algorithm determines number of source-level statements Language/Compiler/Architecture determine machine instructions (Chapter 2 and 3) Processor/Memory determine how fast instructions are executed (Chapter 5, 6, and 7) Assessing and Understanding Performance in Chapter 4

What is a computer? Components: input (mouse, keyboard) output (display, printer) memory (disk drives, DRAM, SRAM, CD) network Our primary focus: the processor (datapath and control) implemented using millions of transistors Impossible to understand by looking at each transistor We need...

Understanding program performance Hardware or software component How is component affects performance Where is this topic covered? Algorithm Determines both the number of source-level statements and the number of I/O operations executed Other books! Programming language, compiler, and architecture Determines the number of machine instructions for each source-level statement Chapter 2 and 3 Processor and memory system Determines how fast instructions can be executed Chapter 5, 6, and 7 I/O system (hardware and operating system) Determines how fast I/O operations may be executed Chapter 8

FIGURE 1.3 A simplified view of hardware and software as hierarchical layers, shown as concentric circles with hardware in the center and applications software outermost

Abstraction Delving into the depths reveals more information An abstraction omits unneeded detail, helps us cope with complexity What are some of the details that appear in these familiar abstractions?

How do computers work? Need to understand abstractions such as: Applications software Systems software Assembly Language Machine Language Architectural Issues: i.e., Caches, Virtual Memory, Pipelining Sequential logic, finite state machines Combinational logic, arithmetic circuits Boolean logic, 1s and 0s Transistors used to build logic gates (CMOS) Semiconductors/Silicon used to build transistors Properties of atoms, electrons, and quantum dynamics So much to learn!

FIGURE 1.5 The organization of a computer, showing the five classic components

FIGURE 1.6 A desktop computer

FIGURE 1.7 Each coordinate in the frame buffer on the left determines the shade of the corresponding coordinate for the raster scan CRT display on the right.

FIGURE 1.8 Inside the personal computer of Figure 1.6 on page 17.

FIGURE 1.9 Inside the processor chip used on the board shown in Figure 1.8.

FIGURE 1.10 Close-up of PC motherboard.

FIGURE 1.11 A disk showing 10 disk platters and the read/write heads.

Instruction Set Architecture 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 True or False: Binary compatibility is extraordinarily important? Modern instruction set architectures: IA-32, PowerPC, MIPS, SPARC, ARM, and others

FIGURE 1.12 Relative performance per unit cost of technologies used in computers over time. Year Technology used in computers Relative performance/unit cost 1951 Vacuum tube 1 1965 Transistor 35 1975 Integrated circuit 900 1995 Very large scale integrated circuit 2,400,000 2005 Ultra large scale integrated circuit 6,200,000,000

FIGURE 1.13 Growth of capacity per DRAM chip over time.

FIGURE 1.14 The chip manufacturing process.

FIGURE 1.15 An 8-inch (200-mm) diameter wafer containing Intel Pentium 4 processors.

FIGURE 1.16 An Intel Pentium 4 (3.06 GHz) mounted on top of its heat sink, which is designed to remove the 82 watts generated within the die.

FIGURE 1.17 Performance increase of workstations, 1987-2003.

Historical Perspective ENIAC built in World War II was the first general purpose computer Used for computing artillery firing tables 80 feet long by 8.5 feet high and several feet wide Each of the twenty 10 digit registers was 2 feet long Used 18,000 vacuum tubes Performed 1900 additions per second Since then: Moore’s Law: transistor capacity doubles every 18-24 months