DSE LECTURE 1 -LRW_ Introduction_to_Computer.pptx

CAO

1. KCES’S COLLEGE OF ENGINEERING AND MANAGEMENT, JALGAON Computer Architecture and Organization Presented by MRS. LEENA RAJESH WAGHULDE COMPUTER ENGINEERING DEPARTMENT

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6. What is a Computer ? A computer is a general purpose device that can be programmed to process information, and yield meaningful results. 6

7. What is Computer Architecture and Computer Organization  ? Computer Architecture: Computer Architecture is concerned with the way hardware components are connected together to form a computer system. Computer Architecture is a functional description of requirements and design implementation for the various parts of computer. It deals with functional behaviour of computer system. It comes before the computer organization while designing a computer. Computer Organization: The actual implementation of a computer in hardware. It acts as the interface between hardware and software. Computer Organization comes after the decide of Computer Architecture first. Computer Organization is how operational attribute are linked together and contribute to realise the architectural specification. Computer Organization deals with structural relationship. 7

8. Computer Architecture Computer Organization Computer Architecture is concerned with the way hardware components are connected together to form a computer system. Computer Organization is concerned with the structure and behaviour of a computer system as seen by the user. It acts as the interface between hardware and software. It deals with the components of a connection in a system. Computer Architecture helps us to understand the functionalities of a system. Computer Organization tells us how exactly all the units in the system are arranged and interconnected. A programmer can view architecture in terms of instructions, addressing modes and registers. Whereas Organization expresses the realization of architecture. While designing a computer system architecture is considered first. An organization is done on the basis of architecture. Computer Architecture deals with high-level design issues. Computer Organization deals with low-level design issues. Architecture involves Logic (Instruction sets, Addressing modes, Data types, Cache optimization) Organization involves Physical Components (Circuit design, Adders, Signals, Peripherals) Computer Architecture VS Computer Organization

9. Food for Thought ... What is the most intelligent computer or human brain  ? 9

10. Answer ... Our brilliant brains 10

11. How does an Electronic Computer Differ from our Brain  ? Computers are ultra-fast and ultra-dumb Feature Computer Our Brilliant Brain Intelligence Dumb Intelligent Speed of basic calculations Ultra-fast Slow Can get tired Never After sometime Can get bored Never Almost always 11

12. How does it work ? Program – List of instructions given to the computer Information store – data, images, files, videos Computer – Process the information store according to the instructions in the program Computer Program Information store results 12 Computer Memory Hard disk Memory – Stores programs and data. Gets destroyed when the computer is powered off Hard disk – stores programs/data permanently

13. Let us make it a full system ... 13 Taking in information is called  input , storing information is better known as  memory  (or storage), chewing information is also known as  processing , and spitting out results is called  output .

14. COMPUTER FUNCTIONS AND STRUCTURES

15. How to Instruct a Computer ? Write a program in a high level language – C, C++, Java Compile it into a format that the computer understands Execute the program Program Executable Output compile execute 15

16. What Can a Computer Under stand  ? Computer can clearly NOT understand instructions of the form Multiply two matrices Compute the determinant of a matrix Find the shortest path between Mumbai and Delhi They understand : Add a + b to get c Multiply a * b to get c 16

17. The Language of Instructions Humans can understand Complicated sentences English, French, Spanish Computers can understand Very simple instructions. Computers don't understand words or numbers the way humans do. To make sense of complicated data, your computer has to encode it in binary . Binary is a base 2 number system. Base 2 means there are only two digits—1 and 0—which correspond to the on and off states your computer can understand 17

18. Generation of Computers

19. Generation of Computers Cont…

20. A computer is an electronic device that generates output in the form of useful information when the input is given to it by the user. A computer accepts input in different forms such as data, program and user replay. Classify the computer according to the following three criteria: Based on operating principles Based on applications Based on size and capability Classification of Computer

21. 1) Based on Operating Principles Analog computers Digital Computers Hybrid Computers 2) Based on Application General purpose computers Special purpose computers 3) Based on size and Capabilities Microcomputers Mini computers Mainframe computer Super computers Classification of Computer Cont….

22. Basic Function of Computer An electronic data processing device, which requires input raw data for processing and generates the output in desired form. It stores the data in its memory which can be accessed any number of times for reference from its memory. It is made up of a lot of electronics, software and mechanical parts. A computer is divided into three basic units namely: Input Unit Central Processing Unit Output Unit

23. Functions of a Computer Data is entered into computer using Input Devices. Data or Instructions are stored in the computer in its memory and processed or uses them as and when required. Data is processed and converted into useful information. Output is generated as per format. Control Mechanism is established for controlling all the functions. We can divide computer in Hardware and Software: Hardware: Keyboard, mouse, joy stick, microphone, camera, printer, monitor, Hard disk, CD, DVD, CPU, motherboard, RAM etc are known as Hardware. Software: System Software & Application Software. Basic Function of Computer Cont…

24. Advantage of Computers A Computer has a very High Speed of processing i.e can perform large amount of data very quickly. Computers are very accurate. Computers are very fast devices. Once the correct input is given to the computers, the output is 100% accurate. It has a large memory capacity. It can store a large amount of information for a large time. It is a reliable device. Basic Function of Computer Cont…

25. Action Device Function A user running a text-editor program types the letter Z on the keyboard. The keyboard sends a code representing the letter Z to the CPU. Keyboard Input The CPU processes the code and determines what letter was typed. Then the CPU sends instructions to the monitor to display the letter Z. CPU Process The monitor displays the letter Z. Monitor Output The user clicks the save button. The mouse sends a code representing the click. Mouse Input The CPU processes the code and determines what action was clicked. CPU Process The following table lists a few sample actions along with the name of devices and functions that are used when they are performed

26. There are basically two types of Digital Computer architecture. These two processor architecture can be classified by how they use memory. The first one is called as Von Neumann architecture and the later is called Harvard architecture. Von Neumann architecture has been around science the 1940s. It is named after the mathematician and early computer scientist John Von Neumann. Von Neumann Architecture and Harvard Architecture

27. In a Von Neumann architecture the same memory and bus are used to store both data and instructions that run the program. The Von Neumann architecture is susceptible to bottlenecks and system performance is affected. The processor need two clock cycle to complete an instruction. So pipelining is not possible with this architecture. A Von Neumann-based computer: Uses a single processor Uses one memory for both instructions and data. Executes programs following the fetch-decode-execute cycle Von Neumann Architectu re

28. Von Neumann Architecture Cont …….

29. Von Neumann Architecture Cont …….

30. Components of Von-Neumann Model: Central Processing Unit Buses Memory Unit A. Central Processing Unit (CPU) The Central Processing Unit ( CPU ) is the electronic circuit responsible for executing the instructions of a computer program. It is sometimes referred to as the microprocessor or processor. The CPU contains the ALU, CU and a variety of resisters. . Von Neumann Architecture Cont …….

31. MAR Memory Address Register Holds the memory location of data that needs to be accessed MDR Memory Data Register Holds data that is being transferred to or from memory AC Accumulator Where intermediate arithmetic and logic results are stored PC Program Counter Contains the address of the next instruction to be executed Von Neumann Architecture Cont ……. 1. Operational Registers Registers are high speed storage areas in the CPU.  All data must be stored in a register before it can be processed

32. 2. Arithmetic and Logic Unit (ALU) The ALU allows arithmetic (add, subtract etc) and logic (AND, OR, NOT etc) operations to be carried out. 3. Control Unit (CU) The control unit controls the operation of the computer’s ALU, memory and input/output devices, telling them how to respond to the program instructions it has just read and interpreted from the memory unit. 4. Program Counter(PC) It has the location of the next instruction to be executed. Program counter then passes this next address to memory address register. 5. Input/output System: Input devices are used to read data into main memory with the help of CPU input instruction. The information from a computer as output are given through Output devices. Computer gives the results of computation with the help of output devices. Von Neumann Architecture Cont …….

33. B. Buses Buses are the means by which data is transmitted from one part of a computer to another, connecting all major internal components to the CPU and memory. A standard CPU system bus is comprised of a control bus, data bus and address bus. Address Bus Carries the addresses of data (but not the data) between the processor and memory Data Bus Carries data between the processor, the memory unit and the input/output devices Control Bus Carries control signals/commands from the CPU (and status signals from other devices) in order to control and coordinate all the activities within the computer Von Neumann Architecture Cont …….

34. C. Memory Unit The memory unit consists of RAM, sometimes referred to as primary or main memory.  Unlike a hard drive (secondary memory), this memory is fast and also directly accessible by the CPU. RAM is split into partitions.  Each partition consists of an address and its contents (both in binary form). The address will uniquely identify every location in the memory. Von Neumann Architecture Cont …….

35. In a normal computer follows von Neumann architecture, instructions and data both are stored in same memory. So same buses are used to fetch instructions and data. This means CPU cannot do both things together (read a instruction and read/write data). Harvard Architecture is the computer architecture that contains separate storage and separate buses (signal path) for instruction and data. It was basically developed to overcome the bottleneck of Von Neumann Architecture. The main advantage of having separate buses for instruction and data is that CPU can access instructions and read/write data at the same time. Harvard Architecture

36. Structure of Harvard Architecture The Harvard architecture has a separate bus for signals and storage

37. Harvard Architecture

38. Components of Harvard Architecture 1. Buses 2. Operational Registers 3. Program Counter 4. Arithmetic and Logic Unit 5. Control Unit 6. Input/output System Structure of Harvard Architecture Cont......

39. VON NEUMANN ARCHITECTURE HARVARD ARCHITECTURE It is ancient computer architecture based on stored program computer concept. It is modern computer architecture based on Harvard Mark I relay based model. Same physical memory address is used for instructions and data. Separate physical memory address is used for instructions and data. There is common bus for data and instruction transfer. Separate buses are used for transferring data and instruction. Two clock cycles are required to execute single instruction. An instruction is executed in a single cycle. It is cheaper in cost. It is costly than van Neumann architecture. CPU can not access instructions and read/write at the same time. CPU can access instructions and read/write at the same time. It is used in personal computers and small computers. It is used in micro controllers and signal processing. Difference between Von Neumann and Harvard Architecture

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