What is CPU in a computer?
CPU means the “Central Processing Unit” of a computer. Another hand, we can introduce it as the brain of a computer or the principal part of any digital computer. Principal components of the CPU are arithmetic logical unit(ALU), control unit, memory registers and CPU interconnection. Those components do various operations in a computer.
In modern computers, CPU is contained on a single chip which is called as microprocessor. As well as, some computers use multi-core processors. Multi-core processor is a single chip which contains two or more CPUs.
When we recall the history of computers, we can identify that the name CPU has come with the advent of stored-program computer. Early CPUs were used as only a part of distinctive computers. But in modern days, microprocessor is used in most of the electronic devices ranging from automobiles to cell phones. As I mentioned, the different components of CPU do various operations. Let’s talk about them.
ARITHMETIC AND LOGICAL UNIT(ALU)
It can be introduced as a circuit which is used to perform arithmetic and logical operations in a computer. It can perform arithmetic operations are like addition, subtraction, multiplication, division. As well as it can perform logical operations such as AND, OR, NOT. In modern computers there are more powerful and complex ALUs. Most of the operations of a CPU are performed by one or more ALUs. All input data are transferred from main memory to the ALU for processing and then the input data are processed according to the arithmetic and logical operations.
CONTROL UNIT
Control unit is the component which controls all the operations of a computer system. Control unit generates signal to direct various hardware components which are connected to the computer. This component checks whether the signals have been communicated correctly to the correct place. Internally control unit also has four components.
- Program counter(It contains the address of the next instruction to be fetched)
- Timing and control logic unit(It generates clock signals)
- Instruction decoder(It decodes the machine instruction format)
- Instruction register(It holds the current instruction that is being decoded)
MEMORY REGISTERS
They are used to store and transfer data quickly according to the need of CPU .Data and instructions which are collected from users, are stored in a specific location by memory registers. The tasks are interpreted and stored by the registers and whenever users ask for same tasks , registers will produce them.
CPU INTERCONNECTION
It can be introduced as the mechanism which provides for communication among the control unit, ALU and registers.
After considering about all those facts you can clearly understand that it is right to call CPU as brain of the computer.
Sathsara Soysa, Computer Engineering Undergraduate of Faculty of Engineering, University of Ruhuna
