Basics Knowledge Of Computer for Competitive Examination (Processor)

2. Processor

• Processor :

   The term CPU and processor are used interchangeably. Cpu acts as the brain of the computer system. Whatever instructions the user gives to the computer, CPU organizes them and executes them. The processor is attached to the circuit board known as a motherboard which contains all the circuits to connect the processor to the rest of the hardware. CPU or processor is the most important component in a computer without which nothing can be done.

 CPU has two parts:-

   (1) Control Unit (CU)

   (2) Arithmetic Logic Unit (ALU)

   The control unit selects and interprets program instructions and then coordinates their execution.

   ALU is responsible for the actual execution of instructions during the data processing operations. When the control unit encounters an instruction that involves an arithmetic operation (i.e. addition, Subtraction, Multiplication, Division) or a logic operation (i.e. less than, equal to, greater than) it passes control to ALU.

   Notes:- When the entire CPU (CU and ALU) is contained on a single tiny silicon chip, it is known as a microprocessor.

   Registers are the part of CPU which is used to hold information temporarily. Resisters help to make the movement of data between different units of computers to increase the transfer speed of the information.

   There are two types of processors:-

   1. CISC Processors

   2. RISC Processors

   CISC stands for Complex Instruction Set Computing. It has a large instruction set, variable-length instructions, and a variety of addressing modes.

   RISC stands for Reduced Instruction Set Computing. It has a small instruction set, fixed-length instructions, and reduced references to memory to retrieve operands.