CPU (Central processing unit)

CPU (Central processing unit)

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  Course Title &Code CSE-100 Introduction to Computer Systems Sessional
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  COMPUTER HARDWARE CPU
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  CPU (Central processingunit)
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  Definition A central processingunit is the electronic circuitry within a computer that caries out the instructions of a computer program by performing the basic arithmetic, logical, control and input/output operations specified by the instructions.
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  COMPONENTS OF CPU CONTROLUNIT(CU) ARITHEMATIC LOGIC UNIT (AU) A NUMBER OF REGISTERS
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  How CPU Works
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  CONTROL UNIT (CU) Control Unit controls operations of other parts of CPU as well as all parts of computer by sending a control signal control sequence of instruction to be executed control flow of data among all parts of computer interpret instructions regulate timing of processor send control single to and receive control single from peripheral devices
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  ARITHMETIC AND LOGICUNIT (ALU)  Arithmetic and Logic Unit consists of a complicated set of logic circuit and accumulator. It is mainly responsible for : Calculation Logical comparison and Decision
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  REGI STERS  Theterm is often used to refer only to the group of registers that can be directly indexed for input or output of an instruction, as defined by the instruction set. More properly, these are called the “architected registers“. For instance, the x86 instruction set defines a set of eight 32-bit registers, but a CPU that implements the X86 instruction set will contain many more hardware registers than just these eight.
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  There are severalother classes of registers:  (a) Accumulator: It is most frequently used register used to store data taken from memory. Its number varies from microprocessor to microprocessor.  (b) General Purpose registers: General purpose registers are used to store data and intermediate results during program execution. Its contents can be accessed through assembly programming.  (c) Special purpose Registers: Users do not access these registers. These are used by computer system at the time of program execution. Some types of special purpose registers are given below:
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  Random Access Memory(RAM)  RAM (random access memory) is the place in a computing device where the operating system (OS), application programs and data in current use are kept so they can be quickly reached by the device's processor.
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  Cache Memory  Cachememory, also called CPU memory, is random access memory (RAM) that a computer microprocessor can access more quickly than it can access regular RAM. This memory is typically integrated directly with the CPU chip or placed on a separate chip that has a separate bus interconnect with the CPU.
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  Expansion Bus  Anexpansion bus is an input/output pathway from the CPU to peripheral devices and it is typically made up of a series of slots on the motherboard. Expansion boards (cards) plug into the bus.
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  Motherboard
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  Definition  A motherboardis the physical arrangement in a computer that contains the computer's basic circuitry and components. On the typical motherboard, the circuitry is imprinted or affixed to the surface of a firm planar surface and usually manufactured in a single step. The computer components included in the motherboard are: The microprocessor (Optionally) coprocessors Memory BIOS Expansion slots Interconnecting circuitry Additional components can be added to a motherboard through its expansion slots.
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  MICROPROCESSOR
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  Definition  A microprocessoris a computer processor on a microchip. It's sometimes called a logic chip. It is the "engine" that goes into motion when you turn the computer on. A microprocessor is designed to perform arithmetic and logic operations that make use of small number-holding areas called registers. Typical microprocessor operations include adding, subtracting, comparing two numbers, and fetching numbers from one area to another.
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  BIOS (basic input/outputsystem)  BIOS is the program a personal computer's microprocessor uses to get the computer system started after you turn it on. It also manages data flow between the computer's operating system and attached devices such as the hard disk, video adapter, keyboard, mouse and printer.