1- Introduction.pdf

+ Computer Organization INT203 Computer Evolution and Performance Aspects + What is a computer system? A complete computer system consists more than just a computer. The four main components are: ◼ Hardware - the physical components ◼...

+ Computer Organization INT203 Computer Evolution and Performance Aspects + What is a computer system? A complete computer system consists more than just a computer. The four main components are: ◼ Hardware - the physical components ◼ Operating System - software that allows other pieces of software (applications) and human users to interact with the hardware ◼ Application Programs - specialized softwares like Word, Excel, Firefox ◼ End User - human user or other computers + What is a computer? ◼ A computer is a machine that computes. ◼ It has evolved from mechanical devices like the abacus to the machine we know now ◼ It stores data (words, numbers, or pictures), interacts with external devices (the monitor, printer, speakers), and executes programs. + Function ◼ There are four basic functions that a computer can perform: ◼ Data processing ◼ Data may take a wide variety of forms and the range of processing requirements is broad ◼ Data storage ◼ Short-term ◼ Long-term ◼ Data movement ◼ Input-output (I/O) - when data are received from or delivered to a device (peripheral) that is directly connected to the computer ◼ Data communications – when data are moved over longer distances, to or from a remote device ◼ Control ◼ A control unit manages the computer’s resources and orchestrates the performance of its functional parts in response to instructions +  CPU – controls the operation of the computer and performs its There are four data processing functions main structural components  Main Memory – stores data of the computer:  I/O – moves data between the computer and its external environment  System Interconnection – some mechanism that provides for communication among CPU, main memory, and I/O + ◼ Control Unit CPU ◼ Controls the operation of the CPU and hence the computer Major structural ◼ Arithmetic and Logic Unit (ALU) components: ◼ Performs the computer’s data processing function ◼ Registers ◼ Provide storage internal to the CPU ◼ CPU Interconnection ◼ Some mechanism that provides for communication among the control unit, ALU, and registers  COMPUTER I/O Main memory System Bus CPU CPU Registers ALU Structure Internal Bus Control Unit CONTROL UNIT Sequencing Logic Control Unit Registers and Decoders Control Memory Figure 1.1 A Top-Down View of a Computer + Multicore Computer Structure ◼ Central processing unit (CPU) ◼ Portion of the computer that fetches and executes instructions ◼ Consists of an ALU, a control unit, and registers ◼ Referred to as a processor in a system with a single processing unit ◼ Core ◼ An individual processing unit on a processor chip ◼ May be equivalent in functionality to a CPU on a single-CPU system ◼ Specialized processing units are also referred to as cores ◼ Processor ◼ A physical piece of silicon containing one or more cores ◼ Is the computer component that interprets and executes instructions ◼ Referred to as a multicore processor if it contains multiple cores + Cache Memory ◼ Multiple layers of memory between the processor and main memory ◼ Is smaller and faster than main memory ◼ Used to speed up memory access by placing in the cache data from main memory that is likely to be used in the near future ◼ A greater performance improvement may be obtained by using multiple levels of cache, with level 1 (L1) closest to the core and additional levels (L2, L3, etc.) progressively farther from the core  MOTHERBOARD Main memory chips Processor I/O chips chip PROCESSOR CHIP Core Core Core Core L3 cache L3 cache Core Core Core Core CORE Arithmetic Instruction and logic Load/ logic unit (ALU) store logic L1 I-cache L1 data cache L2 instruction L2 data cache cache Figure 1.2 Simplified View of Major Elements of a Multicore Computer + Motherboard components + Motherboard components + History of Computers First Generation: Vacuum Tubes ◼ Vacuum tubes were used for digital logic elements and memory ◼ Institute for Advanced Study (IAS) computer ◼ Fundamental design approach was the stored program concept ◼ Attributed to the mathematician John von Neumann ◼ First publication of the idea was in 1945 for the Electronic Discrete Variable Computer (EDVAC) ◼ Design began at the Princeton Institute for Advanced Studies ◼ Completed in 1952 ◼ Prototype of all subsequent general-purpose computers  Central processing unit (CPU) Arithmetic-logic unit (CA) AC MQ Input- Arithmetic-logic output circuits equipment (I, O) MBR Instructions and data Instructions and data M(0) M(1) M(2) M(3) PC IBR M(4) AC: Accumulator register MQ: multiply-quotient register MBR: memory buffer register IBR: instruction buffer register MAR IR PC: program counter MAR: memory address register Main IR: insruction register memory (M) Control Control circuits signals M(4092) M(4093) Program control unit (CC) This structure was M(4095) Addresses outlined in von Neumann’s earlier Figure 1.6 IAS Structure proposal  IAS consists of 4,096 storage locations, called words, of 40 binary digits (bits) each 0 1 39 sign bit (a) Number word Each number is represented by a sign bit and a 39-bit value left instruction (20 bits) right instruction (20 bits) 0 8 20 28 39 opcode (8 bits) address (12 bits) opcode (8 bits) address (12 bits) (b) Instruction word Figure 1.7 IAS Memory Formats + Registers Memory buffer register Contains a word to be stored in memory or sent to the I/O unit (MBR) Or is used to receive a word from memory or from the I/O unit Memory address Specifies the address in memory of the word to be written from register (MAR) or read into the MBR Instruction register (IR) Contains the 8-bit opcode instruction being executed Instruction buffer Employed to temporarily hold the right-hand instruction from a register (IBR) word in memory Contains the address of the next instruction pair to be fetched Program counter (PC) from memory Accumulator (AC) and Employed to temporarily hold operands and results of ALU multiplier quotient (MQ) operations + History of Computers Second Generation: Transistors ◼ Smaller ◼ Cheaper ◼ Dissipates less heat than a vacuum tube ◼ Is a solid state device made from silicon ◼ Was invented at Bell Labs in 1947 ◼ It was not until the late 1950’s that fully transistorized computers were commercially available + Table 1.2 Computer Generations Approximate Typical Speed Generation Dates Technology (operations per second) 1 1946–1957 Vacuum tube 40,000 2 1957–1964 Transistor 200,000 3 1965–1971 Small and medium scale 1,000,000 integration 4 1972–1977 Large scale integration 10,000,000 5 1978–1991 Very large scale integration 100,000,000 6 1991- Ultra large scale integration >1,000,000,000 Integration is the process of creating an integrated circuit (IC) by combining large number of metal–oxide–silicon (MOS) transistors onto a single chip. + Second Generation Computers ◼ Introduced: ◼ More complex arithmetic and logic units and control units ◼ The use of high-level programming languages ◼ Provision of system software which provided the ability to: ◼ Load programs ◼ Move data to peripherals ◼ Libraries perform common computations  IBM 7094 computer Peripheral devices Mag tape units CPU Card punch Data channel Line printer Card reader Drum Multi- Data plexor channel Disk 700 series in 1952 Data channel Disk 7000 series in 1964 Hyper- tapes Memory Data Teleprocessing channel equipment Figure 1.9 An IBM 7094 Configuration The multiplexor schedules access to the memory from the CPU and data channels, allowing these devices to act independently. History of Computers Third Generation: Integrated Circuits ◼ 1958 – the invention of the integrated circuit ◼ Discrete component ◼ Single, self-contained transistor ◼ Manufactured separately, packaged in their own containers, and soldered or wired together onto masonite-like circuit boards ◼ Manufacturing process was expensive ◼ The two most important members of the third generation were the IBM System/360 and the PDP-8 (Programmed Data Processor)  Boolean Binary Input logic Output Input storage Output function cell Read Activate Write signal (a) Gate (b) Memory cell Figure 1.10 Fundamental Computer Elements + ◼ A computer consists of gates, Integrated memory cells, and interconnections among these Circuits elements ◼ The gates and memory cells ◼ Data storage – provided by are constructed of simple memory cells digital electronic components ◼ Data processing – provided by gates ◼ Exploits the fact that such components as transistors, resistors, and conductors can be ◼ Data movement – the paths fabricated from a among components are used semiconductor such as silicon to move data from memory to memory and from memory ◼ Many transistors can be through gates to memory produced at the same time on a single wafer of silicon ◼ Control – the paths among components can carry control ◼ Transistors can be connected signals with a processor metallization to form circuits  Wafer Chip Gate Packaged chip Figure 1.11 Relationship Among Wafer, Chip, and Gate  t ui g ed of rc or in ga w d st rk ci ul l a at n te AMD Epyc Rome 39.5 billion (2019) gr tio si o ’s an w om e te n r tr irst in ve p r oo In M F 100 bn 10 bn 1 bn 100 m 10 m 100,000 10.000 1,000 100 10 1 1947 50 55 60 65 70 75 80 85 90 95 2000 05 11 Figure 1.12 Growth in Transistor Count on Integrated Circuits (DRAM memory) Moore’s Law 1965; Gordon Moore – co-founder of Intel Observed number of transistors that could be put on a single chip was doubling every year Consequences of Moore’s law: The pace slowed to a doubling every 18 months in the 1970’s but has sustained The cost of The electrical Computer computer logic path length is becomes smaller Reduction in that rate ever since and memory shortened, power and Fewer and is more interchip circuitry has increasing convenient to cooling fallen at a operating use in a variety connections requirements dramatic rate speed of environments + IBM System/360 ◼ Announced in 1964 ◼ Product line was incompatible with older IBM machines ◼ Was the success of the decade and cemented IBM as the dominant computer vendor ◼ The architecture remains to this day the architecture of IBM’s mainframe computers ◼ Was the industry’s first planned family of computers ◼ Models were compatible in the sense that a program written for one model should be capable of being executed by another model in the series + LSI Large Scale Later Integration Generations VLSI Very Large Scale Integration ULSI Semiconductor Memory Ultra Large Microprocessors Scale Integration + Microprocessors ◼ The density of elements on processor chips continued to rise ◼ More and more elements were placed on each chip so that fewer and fewer chips were needed to construct a single computer processor ◼ 1971 Intel developed 4004 ◼ First chip to contain all of the components of a CPU on a single chip ◼ Birth of microprocessor ◼ 1972 Intel developed 8008 ◼ First 8-bit microprocessor ◼ 1974 Intel developed 8080 ◼ First general purpose microprocessor ◼ Faster, has a richer instruction set, has a large addressing capability Evolution of Intel Microprocessors 4004 8008 8080 8086 8088 Introduced 1971 1972 1974 1978 1979 Clock speeds 108 kHz 108 kHz 2 MHz 2 MHz, 8 MHz, 10 MHz 5 MHz, 8 MHz Bus width 4 bits 8 bits 8 bits 16 bits 8 bits Number of transistors 2,300 3,500 6,000 29,000 29,000 Feature size (m) 10 8 6 3 6 Addressable memory 640 bytes 16 KB 64 KB 1 MB 1 MB (a) 1970s Processors Evolution of Intel Microprocessors 80286 386TM DX 386TM SX 486TM DX CPU Introduced 1982 1985 1988 1989 Clock speeds 6–12.5 MHz 16–33 MHz 16–33 MHz 25–50 MHz Bus width 16 bits 32 bits 16 bits 32 bits Number of transistors 134,000 275,000 275,000 1.2 million Feature size (m) 1.5 1 1 0.8–1 Addressable memory 16 MB 4 GB 16 MB 4 GB Virtual memory 1 GB 64 TB 64 TB 64 TB Cache – – – 8 kB (b) 1980s Processors Evolution of Intel Microprocessors 486TM SX Pentium Pentium Pro Pentium II Introduced 1991 1993 1995 1997 Clock speeds 16–33 MHz 60–166 MHz 150–200 MHz 200–300 MHz Bus width 32 bits 32 bits 64 bits 64 bits Number of transistors 1.185 million 3.1 million 5.5 million 7.5 million Feature size (m) 1 0.8 0.6 0.35 Addressable memory 4 GB 4 GB 64 GB 64 GB Virtual memory 64 TB 64 TB 64 TB 64 TB 512 kB L1 and Cache 8 kB 8 kB 512 kB L2 1 MB L2 (c) 1990s Processors Evolution of Intel Microprocessors Core i7 EE Core i9- Pentium III Pentium 4 Core 2 Duo 4960X 7900X Introduced 1999 2000 2006 2013 2017 1.06–1.2 Clock speeds 450–660 MHz 1.3–1.8 GHz 4 GHz 4.3 GHz GHz Bus width 64 bits 64 bits 64 bits 64 bits 64 bits Number of transistors 9.5 million 42 million 167 million 1.86 billion 7.2 billion Feature size (nm) 250 180 65 22 14 Addressable memory 64 GB 64 GB 64 GB 64 GB 128 GB Virtual memory 64 TB 64 TB 64 TB 64 TB 64 TB 1.5 MB L2/ Cache 512 kB L2 256 kB L2 2 MB L2 14 MB L3 1.5 MB L3 Number of cores 1 1 2 6 10 + The Evolution of the Intel x86 Architecture ◼ Two processor families are the Intel x86 and the ARM architectures ◼ Current x86 offerings represent the results of decades of design effort on complex instruction set computers (CISCs) ◼ An alternative approach to processor design is the reduced instruction set computer (RISC) ◼ Acorn RISC Machine (ARM) architecture is used in a wide variety of embedded systems and is one of the most powerful and best-designed RISC-based systems on the market + Embedded Systems ◼ The use of electronics and software within a product ◼ Billions of computer systems are produced each year that are embedded within larger devices ◼ Today many devices that use electric power have an embedded computing system ◼ Often embedded systems are tightly coupled to their environment ◼ This can give rise to real-time constraints imposed by the need to interact with the environment ◼ Constraints such as required speeds of motion, required precision of measurement, and required time durations, dictate the timing of software operations ◼ If multiple activities must be managed simultaneously this imposes more complex real-time constraints + Embedded Application Processors Operating versus Systems Dedicated Processors ◼ There are two general ◼ Application processors approaches to developing an ◼ Defined by the processor’s ability to execute complex operating embedded operating system systems (OS): ◼ General-purpose in nature ◼ Take an existing OS and ◼ An example is the smartphone – the embedded system is designed adapt it for the embedded to support numerous apps and application perform a wide variety of functions ◼ Design and implement an ◼ Dedicated processor OS intended solely for ◼ Is dedicated to one or a small embedded use number of specific tasks required by the host device ◼ Because such an embedded system is dedicated to a specific task or tasks, the processor and associated components can be engineered to reduce size and cost + ARM Refers to a processor architecture that has evolved from RISC design principles and is used in embedded systems Family of RISC-based microprocessors and microcontrollers designed by ARM Holdings, Cambridge, England Chips are high-speed processors that are known for their small die size and low power requirements Probably the most widely used embedded processor architecture and indeed the most widely used processor architecture of any kind in the world Acorn RISC Machine/Advanced RISC Machine + Designing for Performance ◼ The cost of computer systems continues to drop dramatically, while the performance and capacity of those systems continue to rise equally dramatically ◼ Today’s laptops have the computing power of an IBM mainframe from 10 or 15 years ago ◼ Processors are so inexpensive that we now have microprocessors we throw away ◼ Desktop applications that require the great power of today’s microprocessor-based systems include: ◼ Image processing ◼ Three-dimensional rendering ◼ Speech recognition ◼ Videoconferencing ◼ Multimedia authoring ◼ Voice and video annotation of files ◼ Simulation modeling ◼ Businesses are relying on increasingly powerful servers to handle transaction and database processing and to support massive client/server networks that have replaced the huge mainframe computer centers of yesteryear ◼ Cloud service providers use massive high-performance banks of servers to satisfy high-volume, high-transaction-rate applications for a broad spectrum of clients