Common CPU components and their functions
The Central processing unit - the brain of the computer that processes program instructions. consists of six main components:
- The component of the CPU that manages instructions.
- A component of the CPU that performs arithmetic and logic calculations.
- The section of high speed memory within the CPU that stores data to be processed.
- A piece of temporary memory. It can refer to a part of the RAM, storage disk, CPU, or an area for storing web pages.
- A channel of communication used to transport data and instructions in the CPU.
- A component of the CPU that sends out regular pulses. Its job is to synchronise the computer's hardware components.
All components work together to allow processing and system control.
Control unit
The CU provides several functions:
- it Retrieve data from memory., Interpret an instruction. and Carry out an instruction. instructions
- it issues control signals that control The physical parts of a computer system, eg a graphics card, hard disk drive or CD drive.
- it moves Units of information. In computing there can be different data types, including integers, characters and Boolean. Data is often acted on by instructions. around the system
Arithmetic logic unit
The ALU has two main functions:
- It performs arithmetic and logical operations (decisions). The ALU is where calculations are done and where decisions are made.
- It acts as a gateway between primary The part of a computer that stores data. and Non-volatile memory external to the CPU and used for long-term storage of programs and data. . Data transferred between them passes through the ALU.
Cache
Cache is a small amount of high-speed Random access memory. This is volatile memory that is constantly being written to and read from. It does not retain its contents without a constant supply of power. When a computer is turned off, everything stored in its RAM is lost. built directly within the processor. It is used to temporarily hold data and instructions that the processor is likely to reuse. This allows for faster processing as the processor does not have to wait for the data and instructions to be fetched from the RAM.
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 being decoded
- the results of calculations
Different processors have different numbers of registers for different purposes, but most have some, or all, of the following:
- program counter
- memory address register (MAR)
- memory data register (MDR)
- current instruction register (CIR)
- accumulator (ACC)
