Processor

Processor

The cpu is the brain of computer and perform all major calculation and comparision.cpu also control the other units of computer system.

 The computer main components are divided into four parts which is input ,output ,storage and cpu. In which storage unit is divided into two parts ,which are primary and secondary. now, you are in position, to know that cpu perform all major activities with the help of its main memory(ram),cache memory,decoder,registers. 

Control unit

The two basic components of cpu are control unit and arithmetic logic unit(alu).the control unit of a cpu select and interpret program instruction also directs their sequence of execution. This process is guided by special purpose registers named instruction register and program control register which holds the current instruction and next instruction for execution. Where as decoder decodes the instruction and interprets instruction.but all the activities done by control unit does not perform any actual processing of data. All the instruction from program received  from main memory (ram) interprets the instruction and give signals to other units to execute them.

Arithmetic logic unit(alu)

Alu a  component of cpu is actual place where execution of instruction takes place during data processing. Alu has some special purpose registers and circuitry to carry out all arithmetic and logic operation . Whenever control unit get some instruction which involves arithmetic or logic operation,it passes the control to alu.

Arithmetic operation involves mathematical operation such as addition , subtraction, multiplication etc., and logic operation involves, less than or greater than or equal to. 

Every cpu has its own set of machine instruction called its instruction set. A cpu has more than 200 instruction in their instruction set.

Registers

Registers are special memory units ,which do transfer of information between various units of computer.

Registers uses bits to store its data. length of registers is equal to number of bits it can store. The length of registers of computers is called its word size.

There are number of registers varies from computer to computer. Some of them are common to all computers. Such as -

program control register, instruction register,memory address register, memory buffer register, i/o register.

Processor speed

Control unit and alu performs operation at very fast speed. These operations are done simultaneously with system clock ,which are built in ability in cpu. which emits millions of electric pulses per second.   Which is called clock cycles. Moving a byte of data from one memory location to another is referred as one cycle. To fetch ,decode and execute a single program instruction more than one clock cycles are needed. As usual, if clock cycles is short then processor will be fast. An instruction directly depends on the computer's built in clock speed which is defined as number of pulses produced per second .clock speed is measured in megahertz or gigahertz where megahertz means 10 to the power 6 and gigahertz means 10 to the power 9 and hertz means cycles per second. Today's personal computers have clock speed ,which range in 0.5ghz to 4.0 ghz. Modern day processors has a power to execute more than one instruction in single clock cycles. It is possible by having multiple alu on a single cpu chip therefore it can execute two or more instruction at the same time.

Types of processors 

Cisic processors

Risc processors

Epic processors

Multicore processorsa

Power efficient processors.