Download - Cpu
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The Central processing Unit
Machine Cycle
Information processing cycle
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The Central processing Unit•The CPU interprets instructions to the computer, performs the logical and arithmetic processing operations, and causes the input and output operations to occur. •consists of hundreds of thousands or millions of electronic circuits.•In today's PCs the CPU is contained in a single silicon chip called a microprocessor chip•It is considered the “brain” of the computer.•Also called the CPU as PROCESSOR & MICROPROCCESSOR
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Intel Pentium D AMD Athlion 64 Intel Pentium M
Pentium DPentium I-IVPentium MCeleronCore i7Core 2 Duo
AMDAthelon 64 X2Athelon 64Turion 64Sempron
Storage (Pimary/Secondary Memory)
Storage (Pimary/Secondary Memory)
Input OutputProcesorProcesor
HOW THESE COMPUTER WORKS?
Monitor,Printer
CPU must be connected to input device, output device and storage device to carry out the
activities
DataData InformationInformation
INFORMATION PROCESSING CYCLE
DataData InformationInformation
Processor / CPU
The Control processing unit (CPU) controls all activities within the system. For every instruction, the control unit repeats a set of four basic operations called the MACHINE CYCLE
A CPU consists of two subcomponents:-1. Control Unit (CU)2.Arithmetic Logic Unit (ALU).
Machine Cycle
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FETCHING
EXECUTING
STORING DECODING
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Machine Cycle
• 4 step in Machine Cycle :
• Step 1:Fetch – retrieve an instruction from memory
• Step 2:Decode – translate instruction in a form ALU can understand (command )
• Step 3:Execute – Carry out instruction• Step 4:Store – copy results to Memory
Processor
Control Unit
MEMORY
ALU
How it’s work ?
Step 1. Fetch Calls an instruction into memory. User want to calculate 2 +2
Step 2.
Decode Translate instruction into commands (to binary form)
Eg : 1110000
Step 4. Store Write result to memory
Step 3. Execute
Does the decoded instructionAdd 2+2
Four operations of the CPU comprise a machine cycle
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Control Unit
Control Unit’s main function in CPU to process data.
1.The Control Unit extracts instructions from memory and decodes and executes them.
2.Manages all resources of a computer
3.Manages a 4-step basic operation which is called a machine cycle or processing cycle.
The Arithmetic-Logic Unit and Control Unit
• An arithmetic logic unit (ALU) and control unit is one of the core components of all central processing units.
• Arithmetic operations: e.g., add, subtract, multiply, divide, square root, cosine, etc.
• Logical operations: e.g., compare two numbers to see which is greater, check whether a true/false statement is true, etc.
• Comparison operation : e.g:AND, OR, NOT, NAND, NOR, XOR and equacalence (=)
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Factors Affecting Processing Speed
• Clock rate of the CPU
• Computer word size
• Bus speed
• Main memory size
• Cache memory size
• instruction set complexity
• Number of processing units
Which computer should I buy?
Desktop
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