Computer Science. The English Language Perspective - Беликова (1176925), страница 6
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A prominent example of both thesephenomena is the IBM System 370 architecture. Thisarchitecture was first introduced in 1970 and included anumber of models. Over the years, IBM has introduced manynew models with improved technology to replace older models,offering the customer greater speed, lower cost, or both. Thesenewer models retained the same architecture so that thecustomer’s software investment was protected. Remarkably, theSystem 370 architecture, with a few enhancements, hassurvived to this day IBM’s mainframe product line.The modern computer is a remarkably complex andsophisticated device, but its fundamental principles ofoperation have really changed remarkably little since the32earliest mechanical computers, and in particular, since IASmachine designed by John von Neumann at the Institute forAdvanced Studies, Princeton, in the 1940s.
The so-called vonNeumann architecture is at the heart of almost every moderninformation processing system. It is based on three keyconcepts:- data and instructions are stored in a single read-writememory,- the contents of this memory are addressable by location,without regard to the type of data contained there,- execution occurs in a sequential fashion (unless explicitlymodified) from one instruction to the next.Contemporary architectures fall into three classes. ComplexInstruction Set Computers (CISC) typically include largenumbers of machine instructions of many different styles.
Thatcomplexity poses difficulties of implementation, because eachstyle of instruction may require substantial real estate on thecomputer chip. Reduced Instruction Set Computers (RISC) aredefined by smaller numbers of machine instructions of very fewstyles. The savings in space on a computer chip can, infavorable situations, make possible intrinsically faster circuitry.RISC programs can thus potentially execute faster than CISCprograms, even though they usually contain more machineinstructions.
The third and newest class of contemporaryarchitecture, Explicitly Parallel Instruction Computers (EPIC),includes the Itanium architecture.Computer architectures may also be classified according to thewidth of the datapath, the internal components through whichinformation flows, e.g., 64 bits for Itanium architecture.When new architectures emerge, they may appear to beevolutionary because they evince strong family resemblances toearlier architectures from the same vendor. On the other hand,they appear revolutionary because they offer a clean break withthe past.In a class of computers called microcomputers, the relationshipbetween architecture and organization is very close. Changes in33technology not only influence organization but also result in theintroduction of more powerful and more complex architectures.Generally, there is less of a requirement for generation-togeneration compatibility for these smaller machines.
Thus,there is more interplay between organizational andarchitectural design decisions.Notes:IAS - Institute for Advanced Studies, PrincetonCISC (Complex Instruction Set Computer) - процессор сосложным набором команд - традиционная архитектурапроцессоровRISC (Reduced Instruction Set Computer) - компьютер ссокращенным набором командEPIC (Explicitly Parallel Instruction Computer) – компьютер сзаданным параллелизмом команд. В этой технологиикомпилятор говорит процессору, какие команды можноисполнять параллельно, а какие зависят от других командAssignments1.
Translate the sentences from the text into Russian inwriting paying attention to the underlined words andphrases:1. Furthermore, a particular architecture may span manyyears and encompass a number of different computermodels, its organization changing with changingtechnology.2. Remarkably, the System 370 architecture, with a fewenhancements, has survived to this day IBM’smainframe product line.343.
That complexity poses difficulties of implementation,because each style of instruction may require substantialreal estate on the computer chip.4. When new architectures emerge, they may appear to beevolutionary because they evince strong familyresemblances to earlier architectures from the samevendor.5. On the other hand, they appear revolutionary becausethey offer a clean break with the past.6. Generally, there is less of a requirement for generationto- generation compatibility for these smaller machines.2. Answer the following questions:1. Define the distinction between architecture andorganization of a computer.2. What is a family of computer models?3.
Which spans longer: a computer architecture or acomputer model?4. What are the key concepts of von Neumannarchitecture?5. Name the classes of contemporary architectures.6. What is the relationship between architecture andorganization in microcomputers?3. Translate into English:Принципы фон Неймана1. Использование двоичной системы счисления ввычислительныхмашинах.Преимуществопереддесятичной системой заключается в том, что устройстваможно делать достаточно простыми.2.
Программное управление ЭВМ. Работа ЭВМконтролируется программой, состоящей из набора команд.Команды выполняются последовательно друг за другом.353. Память компьютера используется не только дляхранения данных, но и программ. При этом и командыпрограммы, и данные кодируются в двоичной системесчисления.4. Ячейки памяти ЭВМ имеют адреса, которыепоследовательно пронумерованы. В любой момент можнообратиться к любой ячейке памяти по ее адресу.
Этотпринцип открыл возможность использовать переменные впрограммировании.5. Возможностьусловного перехода в процессевыполнения программы. Несмотря на то, что командывыполняются последовательно, в программах можнореализовать возможность перехода к любому участку кода.4. Give the summary of the text using the key terms.STRUCTURE AND FUNCTIONSRead the following words and word combinations and usethem for understanding and translation of the text:CPU (Central Processing Unit) – ЦПУ (центральныйпроцессор)bus - шинаto be referred to as - упоминаться как, называтьсяcontrol unit - блок управленияarithmetic logic unit (ALU) - арифметическое логическоеустройство (АЛУ)register - регистр. счетчикbinary - двоичныйto be in charge of - быть ответственным заfetch-execute cycle - цикл выполнения командыinstruction register (IR) - регистр командprogram counter (PC) - счетчик командmain memory - оперативная память36to accomplish - выполнятьvolatile - энергозависимыйcache memory - кэш-памятьbus controller - контроллер шиныmotherboard - материнская платаOne of the major characteristics of the von Neumannarchitecture is that the units that process information areseparate from the units that store information.
Thischaracteristic leads to the following components of thecomputer:- Central processing unit (CPU): Controls the operation ofthe computer and performs its data processing functions;often simply referred to as processor.- Main memory: Stores data.- I/O: Moves data between the computer and its externalenvironment- System interconnection: The mechanism that provides forcommunication among CPU, main memory, and I/O.
Acommon example of interconnection is by means of asystem bus, consisting of a number of conducting wires towhich all the other components attach.These components are interconnected in some fashion toachieve the basic function of the computer, which is to executeprograms. There may be one or more of each aforementionedcomponents. Traditionally, there has been just a singleprocessor. In recent years, there has been increasing use ofmultiple processors in a single computer.CPUThe most complex component is the CPU, with its majorstructural components being as follows:- Control unit, which controls the operation of the CPU andhence the computer- Arithmetic and logic unit (ALU), which performs thecomputer’s data processing functions37- Registers, which provide storage internal to the CPU- CPU interconnection: the mechanism that provides forcommunication among the control unit, ALU, and registers.The ALU is that part of the computer that actually performsarithmetic and logical operations on data.
All of the otherelements of the computer system - control unit, registers,memory, I/O - are there mainly to bring data into the ALU forit to process and then to take the results back out. In a sense, theALU is the core or essence of a computer.An ALU and, indeed, all electronic components in the computerare based on the use of simple digital logic devices that canstore binary digits and perform simple Boolean logicoperations.Most modern ALUs have a small amount of special storageunits called registers. Registers are used to store intermediatevalues or special data, i.e.
information that is needed againimmediately. Access to registers is much faster than access tomemory locations.The control unit is the organizing force in the computer, for it isin charge of the fetch- execute cycle. The steps in the processingcycle are:- Fetch the next instruction.- Decode the instruction.- Get data if needed.- Execute the instruction.There are two registers in the control unit.
The instructionregister (IR) contains the instruction that is being executed, andthe program counter (PC) contains the address of the nextinstruction to be executed.There are several approaches to the implementation of thecontrol unit; one common approach is a microprogrammedimplementation. In essence, a microprogrammed control unitoperates by executing microinstructions that define thefunctionality of the control unit.38Main memoryGenerally speaking, memory is a facility for temporarily storingprogram instructions or data during the course of processing.Within the main memory (sometimes called primary storage),instructions and data are stored in distinct locations so that theycan be distinguished easily. The main memory is often referredto as RAM (random access memory). It acts as a staging postbetween the hard disk and processor. The more data it ispossible to have available in the RAM, the faster the PC willrun.Main memory is attached to the processor via its address anddata buses.
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