CPU MEMORY Powered by De

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CPU Its manage everything held in memory so that the machine keeps track of what is stored, where it is and what type of data it is so that there is no risk of the program instruction being mixed up with output data or any other data. Powered by De. Sia. More 2

Its constitute a microprocessor which is a single microchip attached (which is the main electronic board in the microcomputer) Powered by De. Sia. More 3

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The processor, also called the microprocessor or CPU (for Central Processing Unit), is the brain of the PC. It performs all general computing tasks and coordinates tasks done by memory, video, disk-storage, and other system components. The CPU is central located on the system board. The CPU is a very complex chip that resides directly on the motherboard of most PCs, but may instead reside on a daughter-card that connects to the motherboard via a dedicated specialized slot. Powered by De. Sia. More 5

The CPU is certainly the most important PC component. CPU stands for Central Processing Unit. Let us briefly study that name: • It is processor, because it processed data • It is central, because it is the center of data processing. • It is a unit, because it is a chip which, contain millions of transistors. Without the CPU, there would be no PC! Powered by De. Sia. More 6

CPU REGISTERS & THE PROCESSING CYCLE Within the CPU are a number of high speed, special-purpose memory units called registers which are used to store data read from memory. Instruction registers to store instruction Data registers to store data Program counter registers- to enable the processor to perform the instructions in the correct order; Stack pointer register, which points to a last In First Out (LIFO) stack holding return addresses when an interrupt occurs; Flag which indicate the outcome of operation-4 Exp arithmetic operation may cause overflow Powered by De. Sia. More 7

(Primary storage) -it is Volatile {ROM, RAM} ALU CU (Non volatile) HARDISK CD-ROM FLOPPY-DISK Powered by De. Sia. More 8

CENTRAL PROCESSING UNIT Consisting of TWO component: (I) Arithmetic Logic Unit (ALU) (ii) Control Unit (CU) ALU One of the most obvious processes through which input data has to go is that of calculation Powered by De. Sia. More 9

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CU Control unit & it exercises control over all the other components which exist without the system Instruct the input device to read the quantity and the unit price and to store them in main memory. Instruction the ALU to take copies of the two values and multiply them together to obtain the gross cost and to store this values back in main memory Instruct the ALU to obtain a copy of gross cost and calculate 10%of this figure and to store the result, discount, into main memory Powered by De. Sia. More 11

MAIN MEMORY These memory server a number of separate functions Function as a working storage which holds data currently being processed. Storage area where output data can be held before it is transferred to the printer or to some other output device. It will hold the program currently being executed. Powered by De. Sia. More 12

SECONDARY STORAGE Floppy-disks and CD-Rom being used for Secondary storage and also with the use of the internal hard-disk Powered by De. Sia. More 13

MEMORY (Storage capacity Elements) “Refer chapter One” What is character addressable storage? TYPES OF MEMORY There are several different type of primary storage • Random Access Memory (RAM) • Read Only memory (ROM) • Processor Cache Memory (PCM) Powered by De. Sia. More 14

RANDOM ACCESS MEMORY Can be both from and written to and any location can be accessed independently this in why it is called (Random Access Memory). TYPE OF RAM • DIMM (dynamic memory) • SIMM (static memory) Powered by De. Sia. More 15

DDR DRAM Powered by De. Sia. More 16

ROM Typically used for starting up a computer, and for computer with simple continuous control functions such as PLCs (programmable Logic Controllers) TYPE OF ROM PROM: programmable Read-Only memories that have their contents created electrically by selectively blowing fused links Powered by De. Sia. More 17

EPROM: erasable programmable Read-Only memories. Have their contents created electrically & erased optically by shinning Ultraviolet light through a window on the top of each integrated circuit EEPROM: electrically erasable programmable read only memories. combines the advantages of being updateable in position, using normal computer facilities and controls. Powered by De. Sia. More 18

Processor Cache Memory This is a small amount (512 kilobytes on the Pentium-III processor) of fast, memory placed between the processor and main-memory Powered by De. Sia. More 19

SIMM Powered by De. Sia. More 20