Computer Organization And Architecture PDF

Chapter (2) Computer Organization and Architecture By: Prof. KHALED HUSSEIN William Stallings, “Computer Organization and Architecture”, 6th Edition 1 1  Chapt...

Chapter (2) Computer Organization and Architecture By: Prof. KHALED HUSSEIN William Stallings, “Computer Organization and Architecture”, 6th Edition 1 1  Chapter Contents 1) What is the difference between Computer Architecture and Computer Organization? Architecture Organization 2) Operation of a computer 3) Functional Units & Structure & Function Structure Function Top Level Functional View The CPU Operations The Control Unit (1) Data Movement (2) Data Storage (3) Data Processing (4) Control 4) Functional Units & Structure & Function 2 1) What is the difference between Computer Architecture and Computer Organization? It is necessary to distinguish between Computer Organization and Computer Architecture. Although it is difficult to give precise definitions for these terms, we define them as follows: Computer Organization and Computer Architecture are the terms used in describing digital computer systems. A Programmer is generally more concerned about the architectural features and a designer of computer systems is more concerned about the organizational aspects. Computer Organization describes the function and the way computer components are operated and the way they are connected together to form the computer system. Computer Organization is how features are implemented, or Computer Organization include hardware details such as: Generation of Control Signals. Interface between the computer and peripherals. Memory technologies used. Flow of data, and Control mechanism 3 e.g. Is there a hardware multiply unit or is it done by repeated addition? 1) What is the difference between Computer Architecture and Computer Organization? Computer Architecture deals with the instruction sets, address fields, operation codes, addressing modes, effective utilization of I/O mechanisms and such other aspects which would interest the users of computers. Computer Architecture means:  The structure and behavior of computer as seen by the programmer.  Instruction format, the instruction set and techniques for addressing Memory. Computer Architecture is those attributes visible to the programmer Instruction sets. Address fields. Operation codes. Number of bits used for data representation Effective utilization of I/O mechanisms, and Such other aspects which would interest the users of computers. e.g. Is there a multiply instruction? 4 1) What is the difference between Computer Architecture and Computer Organization? All Intel x86 family share the same basic architecture The IBM System/370 family share the same basic architecture. This gives code compatibility  At least backwards Organization differs between different versions 5 1) What is the difference between Computer Architecture and Computer Organization? Computer Organization Computer Architecture 1) Computer Organization is involved with 1) Computer Architecture is involved with the the mechanism and behavior of a computer method hardware elements are linked to form a system as view by the client (user). computer system. 2) It manages with the elements of a 2) It facilitates as the interface between connection in a system. hardware and software. 3) It defines the realization of structure. 3) A programmer can view architecture in condition of instructions, addressing modes, and Registers. 4) It tells us how accurately all the methods 4) It supports us to learn the functionalities of a in the system are organized and system. interconnected. 5) The function of Computer Organization is 5) It examines instruction formats, instruction to find out and examines the organizational set and addressing technology. It also contains mechanism for its proper operations. the description of several functional modules such as CPU and memories. 6 3) Operation of a computer The computer accepts information in the form of Programs and Data through an input unit and stores it in the Memory. Information stored in the Memory is fetched, under program control, into an Arithmetic and Logic unit, where it is processed. Processed information leaves through an output unit. All activities inside the machine are directed by the Control unit. 7  3) Functional Units & Structure & Function Functional units. Structure is the way in The Structure and Function of which components relate to the computer depict how:  The components of the computer each other. are assembled.  How the components of the Function is the operation computer are interrelated to each other. of individual components as  What operations these part of the structure components perform. 8 3) Structure & Function Functional units A computer consists of five functionally independent main parts: 1. Input unit 2. Memory unit 3. Arithmetic and Logic Unit (ALU) 4. Output unit 5. Control unit 9 3) Functional Units & Structure & Function 1. Input unit Computers accept coded information through input units. The most well known input device is a keyboard. Whenever a key is pressed, the corresponding letter or digit is automatically translated into its corresponding binary code and transmitted over a cable to either the memory or the processor. 10 3) Functional Units & Structure & Function Functional units 2. Memory unit The function of the Memory unit is to store Programs and Data. There are two classes of storage, called Primary and Secondary storages. Primary storage is a fast Memory that operates at electronic speeds. Programs must stay in Memory while they are being executed. 11 3) Functional Units & Structure & Function Functional units 2. Memory unit Primary Storage The Memory contains a large number of Semiconductor storage cells, each capable of storing one bit of information. Random Access Memory in which any location can be reached in a short and fixes amount of time after specifying its address. The time required to access one word is called the Memory access time. Cache Memory The smallest and fattest unit is referred to as Cache Memory. They are tightly coupled with processor and are often contained on the same integrated circuit chip to achieve high performance. Main Memory The largest and slowest unit is referred to as the Main Memory. 12 3) Functional Units & Structure & Function Functional units 2. Memory unit Secondary Storage Although Primary storage is essential, it tends to be expensive. Thus additional, cheaper, Secondary storage is used when large amounts of Data and Programs have to be stored, particularly for information that is accessed infrequently. A wide selection of Secondary storage devices is available, including: Magnetic Disks, Tapes and Optical Disks (CD-ROMs). 13 3) Functional Units & Structure & Function Functional units 3. Arithmetic and Logic Unit (ALU) Most computer operations are executed in in the Arithmetic and Logic Unit (ALU) of the processor. For example, Suppose two numbers are to be added. They are brought into the processor, and the actual addition is carried out by the ALU. The sum may then be stored in the Memory or retained in the processor for immediate use. When operands are brought into the processor, they are stored in high-speed storage elements called Registers. 14 3) Functional Units & Structure & Function Functional units 4. Output unit The output unit is the counterpart of input unit. Its function is to send processed results to the outside world. The most familiar example of such a device is a printer. Some units, such as displays, provide an input function and an output function. The dual role of such units is the reason for using the single name I/O unit in many cases. 15 3) Functional Units & Structure & Function Functional units 5. Control unit The Memory, Arithmetic and Logic, and I/O units store and process information and perform input and output operations. The operations of these units are coordinated by control unit. The control unit is effectively the nerve center that sends control signals to other units and senses their states. 13 3) Functional Units & Structure & Function Function All computer functions are: 1. Data Movement 2. Data Storage 3. Data Processing 4. Control 17 3) Functional Units & Structure & Function Function Functional view 18 3) Functional Units & Structure & Function Function Operations: (1) Data movement 19 3) Functional Units & Structure & Function Function Operations: (2) Data Storage 20 3) Functional Units & Structure & Function Function Operations: (3) Data processing from / to storage 21 3) Functional Units & Structure & Function Function Operations: (4) Processing from storage to I/O (Control) 22 3) Functional Units & Structure & Function Structure Top Level The computer’s operating environment consists of devices that serve as either sources or destinations of data. When data are received from or delivered to a device that is directly connected to the computer, the process is known as input – output (I/O), and the device is referred to as a peripheral. When data are moved over longer distances, to or from a remote device, the process is known as data communications. Peripherals Computer Central Processing Computer Unit (CPU) Main Systems Memory Interconnection Input Output Communication lines 23 3) Functional Units & Structure & Function Structure The CPU CPU Computer Arithmetic Registers and I/O Login Unit System CPU Bus Internal CPU Memory Interconnection Control Unit 24 3) Functional Units & Structure & Function Structure The Control Unit Control Unit CPU Sequencing ALU Login Internal Control Bus Unit Control Unit Registers Registers and Decoders Control Memory 25  The Computer : Top-Level Structure Computer Main Systems Memory Interconnection Input Central Output Processing Unit (CPU) CPU Arithmetic Control Registers and Login Unit Unit Sequencing Control Internal CPU Login Unit Interconnection Registers and Control Decoders Control Memory Unit 26  Assembly language? What is assembly language?  An assembly language is a programming language that communicates with the hardware of a computer directly.  An assembly language allows a software developer to code using words and expressions that can be easier to understand than the binary or hexadecimal data the computer stores and reads. 26  Assembly language? How do assembly languages work?  Assembly languages differ between hardware architectures. A computer's architecture includes its machine components, hardware design, processor and the relationships it has with other machines. Specific computer architectures have corresponding assembly languages. Although the assembly languages are specific to their hardware, they typically run various operating systems, meaning an assembly language can often be compatible with any programming language. 26