Chapter 2: Data Manipulation

Transcription

1 Chapter 2: Data Manipulation Computer Science: An Overview Tenth Edition by J. Glenn Brookshear

2 What is a Computer? Monitor, case, keyboard, mouse, speaker, scanner, webcam, printer, What s inside? 2-2

3 Inside the Case CPU, motherboard, adaptors, hard disk, memory, CDROM, We are going to talk about those. 2-3

4 Central Processing Unit (CPU) An electronic circuit that can execute computer programs Intel i7 AMD K10 IBM Cell ARM Acorn Sun SPARC To understand CPU, we need to know what computer programs are. 2-4

5 Stored Program Concept "The final major step in the development of the general purpose electronic computer was the idea of a stored program..." Brian Randell 2-5

6 What re the Differences? TV: you can watch different channels. 面包机 :you can make different food. Swiss knife: you can use different tools Computer: you can 2-6

7 Magic box You can add more functions to it. How? Program is like data to be input to computers. It can perform multiple functions at a time We will talk about this in the OS lesson. 2-7

8 A Generic Recipe Ingredient: a, b, c, Tools: 锅 炉 刀 Basic operations: 切 洗 炒 煮 Procedure: A sequence of instructions Different using basic operations on ingredients or intermediate products. Can we treat the procedure as an input, just like ingredients? Output: dish x Different The same 8

9 First Try e.g. 面包机 Fixed procedures to choose from 2-9

10 How about Programmable? How to tell the machine to do the procedure that we invent? 2-10

11 Ideal: A Universal Cooking Machine Input: Ingredient a, b, c, Instruction 1, 2, 3, Tool: universal cooking machine Can read instructions and execute them step by step programmable. Have all tools and ability to perform basic operations. Output: dish x 2-11

12 For Computers Data are stored as 0 and 1 Instructions are also expressed and stored as 0 and 1 in memory 2-12

13 Stored-Program Concept Program: a sequence of instructions Stored-program concept: A program can be encoded as bit patterns and stored in main memory, just like data. From there, the CPU can fetch the instructions and execute them. Advantage: programmable We can use a single machine to perform different functions by loading different prog. 2-13

14 Maurice Vincent Wilkes 莫里斯 文森特 威尔克斯爵士 (Maurice Vincent Wilkes), 英国计算机科学家 设计和制造了世界上第一台存储程序式电子计算机 EDSAC, 第二届 (1967 年 ) 的图灵奖获得者 战后, 威尔克斯到剑桥大学, 担任数学实验室 ( 后改名计算机实验室 ) 主任 1946 年 5 月, 他获得了冯 诺伊曼起草的 EDVAC 计算机的设计方案的一份复印件 EDVAC 是 Electronic Discrete Variable Automatic Computer 的缩写, 是宾夕法尼亚大学莫尔学院于 1945 年开始研制的一台计算机, 是按存储程序式思想设计的, 并能对指令进行运算和修改, 因而可自动修改其自身的程序 但由于工程上遇到困难,EDVAC 迟至 1952 年才完成, 造成 研制开始在前, 完工在后 的局面, 而让威尔克斯占去先机 威尔克斯立即以 EDVAC 为蓝本设计自己的计算机并组织实施, 起名为 EDSAC(Electronic Delay Storage Auto-matic Calculator EDSAC 还为剑桥大学著名的生物学家肯德烈 (J.Kendrew) 分析了成百上千张有关分子结构的 X 射线衍射图案的照片, 肯德烈因为这方面的成就而荣获 1962 年诺贝尔奖, 他多次提到 EDSAC 在他的研究工作中所发挥的无可比拟的作用 射电天文学的主要创始人 因发明综合孔径射电望远镜而荣获 1974 年诺贝尔物理奖的马丁 里尔 (Martin Ryle) 也是在 EDSAC 上对获得的天文照片进行分析和综合, 帮助他取得成果的 2-14

15 Maurice Vincent Wilkes 在设计与建造 EDSAC 的过程中, 威尔克斯决不是简单地模仿和照搬 EDVAC 的设计, 而是创造和发明了许多新的技术和概念 诸如 变址 ( 威尔克斯当时称之为 浮动地址 ---- floating address); 宏指令 ( 威尔克斯当时称为 综合指令 --synthetic order ); 微程序设计 ( 将每一条机器指令的执行分解为一系列更基本的微命令 将可同时执行的微命令组合在一起形成微指令 所有这些都对现代计算机的体系结构和程序设计技术产生了深远的影响 EDSAC 和 LEO 计算机的成功奠定了威尔克斯作为计算机大师和先驱在学术界的地位 获奖与荣誉 1980 年获得 ACM 的 Eckert-Mauchly 奖 1968 年获 AFIPS 的 Harry Goode 奖 1981 年获 IEEE 的 McDowell 奖 1982 年获宾夕法尼亚大学的 Pender 奖 1988 年获日本的 C&C 奖 1991 年获意大利的 Italgas 奖 2-15

16 Problems How to convert instructions to operations? This is like Harry Porter s spell. There should be a control unit. To control which function to perform. To control which data to be operated. How can the control unit understand the instructions? What function units should be included? CD players, game console, calculators,? 2-16

17 Outline of the Magic Box Processing unit Control unit Belt Storage unit for instructions and data 2-17

18 Chapter 2: Data Manipulation 2.1 Computer Architecture 2.2 Machine Language 2.3 Program Execution 2.4 Arithmetic/Logic Instructions 2.5 Communicating with Other Devices 2.6 Other Architectures 2-18

19 Von-Neumann Model 19

20 Computer Architecture Central Processing Unit (CPU) or processor Arithmetic/Logic unit versus Control unit Registers General purpose Special purpose Bus Motherboard 2-20

21 Von Neumann Architecture General purpose electronic computer Processing tools Small but fast temporary storage Large temporary storage for data and instructions Fig

22 Stored Program Concept A program can be encoded as bit patterns and stored in main memory. From there, the CPU can then extract the instructions and execute them. In turn, the program to be executed can be altered easily. 2-22

23 23

24 Some concepts Instruction set ( 指令集 ): collection of instructions that a processor can execute A compiler ( 编译器 ) translates a high level language, which is architecture independent, into assembly language, which is architecture dependent. An assembler( 汇编器 ) translates assembly language programs into executable binary codes. For fully compiled languages like C and Fortran, the binary codes are executed directly by the target machine. 24

25 Assembly code Assembler Object code

26 Different for various processor type (size, kind of operation, type of operands, type of results) Incompatibility: in contrast to high-level language (recompile) One exception: Java bytecodes for virtual machine, run on any processor Computer systems are often identified by CPU Instruction set decides the program that can be executed and affect the performance Instruction sets: 80x86 CPU (e.g. IBM PC) ~ Motorola PowerPC CPU (e.g. Apple Macintosh) 26

27 Terminology Machine instruction: An instruction (or command) encoded as a bit pattern recognizable by the CPU Machine language: The set of all instructions recognized by a machine What to do + Specified information 2-27

28 A Typical C Program Development Environment Phases of C Programs: Editor Preprocessor Compiler Linker Loader Disk Disk Disk Disk Disk Primary Memory 1. Program is created in the editor and stored on disk 2. Preprocessor program processes the code 3. Compiler creates object code and stores it on disk. 4. Linker links the object code with the libraries 5. Loader puts program in memory. 1. Edit 2. Preprocess 3. Compile 4. Link 5. Load 6. Execute CPU Primary Memory 6. CPU takes each instruction and executes it, possibly storing new data values as the program executes

29 Machine Language Philosophies Reduced Instruction Set Computing (RISC) Few, simple, efficient, and fast instructions Examples: PowerPC from Apple/IBM/Motorola and SPARK from Sun Microsystems Complex Instruction Set Computing (CISC) Many, convenient, and powerful instructions Example: Pentium from Intel 2-29

30 Machine Instruction Types Data Transfer: copy data from one location to another Arithmetic/Logic: use existing bit patterns to compute a new bit patterns Control: direct the execution of the program 2-30

31 MPIS Instructions 31

32 Arithmetic instructions add: Adds two registers and stores the result in a register, executes a trap on overflow add $d, $s, $t # $d = $s + $t sub subtracts two registers, executes a trap on overflow sub $d,$s,$t $d = $s - $t Comments 32

33 Example: f=(g+h)-(i+j) f,g,h,i,j $s0, $s1, $s2, $s3, $s4 add $t0,$s1,$s2 # g+h add $t1,$s3,$s4 # i+j sub $s0,$t0,$t1 # (g+h)-(i+j) 33

34 Figure 2.2 Adding values stored in memory add $10,$8,$9 MIPS(RISC) 2-34

35 Figure 2.3 Dividing values stored in memory 2-35

36 Figure 2.4 The architecture of the machine described in Appendix C 2-36

37 Parts of a Machine Instruction Op-code( 操作码 ): Specifies which operation to execute Operand( 操作数 ): Gives more detailed information about the operation Interpretation of operand varies depending on op-code 2-37

38 Figure 2.5 and Figure 2.6 store 2-38

39 Program Execution Controlled by two special-purpose registers Program counter( 程序计数器 ): address of next instruction Instruction register( 指令寄存器 ): current instruction Machine Cycle Fetch( 取指 ) Decode( 译码 ) Execute( 执行 ) 2-39

40 Figure 2.8 The machine cycle 2-40

41 Figure 2.9 Decoding the instruction B

42 Figure 2.10 The program from Figure 2.7 stored in main memory ready for execution 2-42

43 Figure 2.11 Performing the fetch step of the machine cycle 2-43

44 Figure 2.11 Performing the fetch step of the machine cycle (cont d) 2-44

45 Figure 2.7 An encoded version of the instructions in Figure

46 Figure 2.10 The program from Figure 2.7 stored in main memory ready for execution 2-46

47 Fetch Instruction 1 Processor Function unit Register Program counter A2 A0 Instruction register 156C Controller F Decode Address bus A0 Data bus 156C Memory C 16 6D E C0 00 6C 6D 6E A0 A1 A2 A3 A4 A5 A6 A7 A8 A9 47

48 Execute Instruction 1 Processor Function unit Register Decode Program counter A2 Instruction register 156C Controller F Address bus 6C Data bus 1 Memory C 16 6D E C0 00 6C 6D 6E A0 A1 A2 A3 A4 A5 A6 A7 A8 A9 48

49 Fetch Instruction 2 Processor Function unit Register 1 Program counter A4 A2 Instruction register 166D Controller F Address bus A2 Data bus 166D Memory C 16 6D E C0 00 6C 6D 6E A0 A1 A2 A3 A4 A5 A6 A7 A8 A9 49

50 Execute Instruction 2 Processor Function unit Register Decode 1 2 Program counter A4 Instruction register 166D Controller F Address bus 6D Data bus 2 Memory C 16 6D E C0 00 6C 6D 6E A0 A1 A2 A3 A4 A5 A6 A7 A8 A9 50

51 Fetch Instruction 3 Processor Function unit Register Program counter A4 A Instruction register 5056 Controller F Address bus A4 Data bus 5056 Memory C 16 6D E C0 00 6C 6D 6E A0 A1 A2 A3 A4 A5 A6 A7 A8 A9 51

52 Execute Instruction 3 Processor Function unit Register Adder Decode Program counter A6 Instruction register 5056 Controller F Address bus Data bus Memory C 16 6D E C0 00 6C 6D 6E A0 A1 A2 A3 A4 A5 A6 A7 A8 A9 52

53 Fetch Instruction 4 Processor Function unit Register Program counter A8 A Instruction register 306E Controller F Address bus A6 Data bus 306E Memory C 16 6D E C0 00 6C 6D 6E A0 A1 A2 A3 A4 A5 A6 A7 A8 A9 53

54 Execute Instruction 4 Processor Function unit Register Decode Program counter A Instruction register 306E Controller F Address bus 6E Data bus 3 Memory C 16 6D E C0 00 6C 6D 6E A0 A1 A2 A3 A4 A5 A6 A7 A8 A9 54

55 Arithmetic/Logic Operations Logic: AND, OR, XOR Masking Rotate and Shift: circular shift, logical shift, arithmetic shift Arithmetic: add, subtract, multiply, divide Precise action depends on how the values are encoded (two s complement versus floatingpoint). 2-55

56 Figure 2.12 Rotating the bit pattern 65 (hexadecimal) one bit to the right 2-56

57 High Level View of Microarchitecture The microarchitecture consists of the control unit and the programmer-visible registers, functional units such as the ALU, and any additional registers that may be required by the control unit. 57

58 A More Detailed View 58

59 59

60 Datapath & Control Datapath A datapath is a collection of functional units, such as arithmetic logic units or multipliers, that perform data processing operations. Control The control commands the datapath, memory, and I/O devices according to the instructions of the program. 60

61 CPU communicats with Other Devices Controller: An intermediary apparatus that handles communication between the computer and a device Specialized controllers for each type of device General purpose controllers (USB and FireWire) Port: The point at which a device connects to a computer Memory-mapped I/O: CPU communicates with peripheral devices as though they were memory cells 2-61

62 Figure 2.13 Controllers attached to a machine s bus 2-62

63 Figure 2.14 A conceptual representation of memory-mapped I/O 2-63

64 Communicating with Other Devices (continued) Direct memory access (DMA): Main memory access by a controller over the bus Von Neumann Bottleneck: Insufficient bus speed impedes performance Handshaking: The process of coordinating the transfer of data between components 2-64

65 Communicating with Other Devices (continued) Parallel Communication: Several communication paths transfer bits simultaneously. Serial Communication: Bits are transferred one after the other over a single communication path. 2-65

66 Data Communication Rates Measurement units Bps: Bits per second Kbps: Kilo-bps (1,000 bps) Mbps: Mega-bps (1,000,000 bps) Gbps: Giga-bps (1,000,000,000 bps) Bandwidth: Maximum available rate 2-66

67 Other Architectures Technologies to increase throughput: Pipelining: Overlap steps of the machine cycle Parallel Processing: Use multiple processors simultaneously SISD: No parallel processing MIMD: Different programs, different data SIMD: Same program, different data 2-67

68 Pipeline Laundry Example A, B, C, D each have one load of clothes to wash, dry, and fold Wash takes 30 minutes Dryer takes 30 minutes Folder takes 30 minutes Stasher takes 30 minutes to put clothes into drawers 68

69 Pipeline Sequential laundry takes 8 hours for 4 loads If they learned pipelining, how long would laundry take? 69

70 Pipeline Pipelined laundry takes 3.5 hours for 4 loads! 70

71 Key Points Stored program concept Central Processing Unit (CPU) Von Neumann Architecture Machine instruction and Machine language Reduced Instruction Set Computing (RISC) Complex Instruction Set Computing (CISC) Machine Instruction Types:Data Transfer, Data Transfer, Control Op-code and Operand Program counter and Instruction register Machine Cycle: Fetch, Decode, Execute Controller, Port, Memory-mapped I/O 2-71