CPU

Computer Processing 

---

Computer perform arithmetic and logical operations upon the input, received from the input devices, with the help of programs of routines (functions) stored in the memory. Another unit manages the flow of information within the various components of the system. Once the result are ready, they are sent to the output unit. 

Let us learn about this process in a little more detail.

Central Processing Unit: CPU is the computer's processing and control circuitry that actually processes input into output.

It contains the following sub-components:

1. Arithmetic and Logic Unit
2. Control Unit
3. System Clock
4. Instruction Set
5. Registers
6. Buses

The central Processing Unit (CPU) of a computer is a piece of hardware that carries out the instructions a computer program. The CPU is like the brains of the computer-every instruction, no matter how simple, has to go through the CPU. It perform the basic arithmetical, logical, and Input/Output operations of a computer system.So let's say you press the letter 'k' on your keyboard and it appears on the screen the CPU of your computer is what makes this possible. The CPU is sometimes also referred to as the Central Processor Unit, or processor for short. So when you are looking at the specifications of a computer at your local electronics store, it typically refers to the CPU as the processor.

When we start to look at the various components of a CPU and how they function, remember that this is all about speed. When we use a computer, we want the instructions to be carried out very fast. As the instructions become more complicated (For example, creating a 3D animation or editing a video file), we demand more from the CPU. Thus, the technological advances we have seen in processor technology have largely been driven by the need for speed.

Arithmetic and Logic Unit (ALU)

Once the data received form the input devices reach CPU, the ALU part of it carries out arithmetical and logical operations on it. Arithmetical operations include addition, subtraction, multiplication, division and other such mathematical calculations. Bit-wise logical operations involve comparisons between data items. The ALU has direct input and output access to the processor controller, main memory and input/output devices. More modern version of the ALU is called FPU (Floating-point Unit) which performs arithmetic operations between two floating type of values.

Control Unit

The Control Unit (CU) various input/output operations and the parts of the computer system. It manages four basic operations:

1. Fatch:Obtaining program instruction form the computer's memory.
2. Decode: Deciphering the program instructions.
3. Execute: Carrying out the requested action.
4. Write Back: Entering the result into the memory.

System Clock

System Clock is an electronic circuit that synchronizes the tasks in the computer. It controls the pace of the events in the computer by generating pulses at rapid rate, measured in millions of cycles per second.

Instruction Set

An instruction set, also known as the command set, is the primary set, of commands that a microprocessor understands. Different types of processors have different instruction sets. For example, RISC (Reduced Instruction Set Computing) microprocessors have relatively smaller instruction sets than CISC (Complex Instruction Set Computing) microprocessors.

Register

A register is a temporary storage location within the CPU. It stores data before it could be processed and keeps track of various operations.

System Bus

A bus is a collection of wires which connects different parts of the CPU to each other, and with the rest of the system. Each bus consists of two parts a data bus and an address bus. The data bus transfers data whereas the address bus transfers information about where the data should go.

A bus has many parallel circuits so that many its can travel at once. The wider the bus, the more quickly data can flow.