A processor, also known as a central processing unit (CPU), is a computer’s primary component that performs most of the processing tasks. It is responsible for executing instructions of a computer program and managing the flow of data through a computer system. It is often referred to as the “brain” of a computer.
Processor major structural components are as follows:
Control unit:
The control unit manages all the computer resources. Think of the control unit as a traffic signal directing the flow of data through the CPU and to and from other devices. The control unit provides several functions:
- It fetches, decodes, and executes the instruction.
- It issues control signals that control hardware.
- It moves data around the system.
Arithmetic Logic Unit:
Because all computer data is stored as numbers, much of the processing that takes place involves comparing numbers or carrying out mathematical operations. In addition to establishing ordered sequences and changing those sequences, the computer can perform two types of operations: arithmetic operations and logical operations. Arithmetic operations include addition, subtraction, multiplication, and division. Logical operations include comparisons, such as determining whether one number is equal to, greater, or less than, other numbers.
Registers:
Registers are small amounts of high-speed memory contained within the CPU. They are used by the processor to store small amounts of data that are needed during processing, such as
- The address of the next instruction to be executed.
- The current instruction is being decoded.
- The results of calculations.
CPU interconnection:
Some mechanism provides for communication among the control unit, ALU, and registers. A bus is a high-speed internal connection. Buses are used to send control signals and data between the processor and other components. Their types of the bus are used:
- Address bus: Carries memory addresses from the processor to other components such as primary memory and I/O devices.
- Data bus: Carries the actual data between the processor and other components.
- Control bus: Carries control signals from the processor to other components. The control bus also carries the clockâs pulses.
