Computer Hardware

MIME-Version : 1 .0 Content-Type : multipart /related boundary "---- _NextPart_01C77911 .A341C570

This document is a Single Web Page , also known as a Web Archive . If you are seeing this message , your browser or editor doesn 't support Web Archive s . download a browser that supports Web Archive , such as Microsoft Internet Explorer

------ _NextPart_01C77911 .A341C570 Content-Location /C /E86C8E85 /COMPUTERHARDWARE .htm Content-Transfer-Encoding : quoted-printable Content-Type : text /html charset "us-ascii

p br

COMPUTER HAR DWARE Central Proc essing Unit (CPU

Put your name here and your school 8217 s

name here A central processing unit (CPU , also known as the processor is the component of a computer that interprets comput er program instructions and processes data . This hardware provides the computer its programmability . This is one of the necessary components found in compu ters of any era , along with primary storage and input /output facilities . A CPU that is manufactured as a s ingle integrated circuit is usually known as a micropr ocessor Beginning in the mid-1970s , microprocessors of ever-increasing complexity a nd power gradually supplanted other designs , and today the term "CPU quot is usually applied to some type of microprocessor CPU operation nb sp The fundamental operation of most CPUs , regardless of the physical form they ta ke is to execute a sequence of stored instructions called a program . The progr am is represented by a series of numbers that are kept in some kind of computer memory . There are four steps that CPUs use in their operation : fetch , decode , execute and write back Fetching involves retrieving an instruction (which is represented by a number or sequence of numbers ) from program memory . The location in program memory is determined by a program counter (PC , which stores a number that identifies the current position in the program . In other words , the program counter keeps track of the CPU 's place in the current program . After an instruction is fetched , the PC is incremented by the length of the instruction word in terms of memory units Often the instruction to be fetched must be retrieved from relatively slow memory , causing the CPU to stall while waiting for the instruction to be returned nb sp The instruction that the CPU fetches from memory is used to determine what the CPU is to do . In decoding , the instruction is broken up into parts that have significance to other portion s of the CPU . The way in which the numerical instruction value is interpreted is defined by the CPU 's instruction set architecture (ISA nb sp After the fetching and decoding , the execute step is performed . D uring this step , various portions of the CPU are connected so they can perform the desired operation . If , for instance , an addition operation was requested , a n arithmetic logic unit (ALU ) will be connected to a set of inputs and a set of outputs . The inputs provide the numbers to be added , and the outputs will contain the final sum . The ALU contains the circuitry to perform simple...