Differences between ALU and CU

ALU (Arithmetic Logic Unit) and CU(Control Unit) are two basic components of the CPU (Central Processing Unit) of a computer system. Today in this article, I will discuss what is ALU, CU their functions and key differences between them.

What is ALU?

ALU is an essential part of CPU which is responsible for performing all the mathematical and logical operations. All the input given to a computer is passed to ALU component of CPU which process this input as directed by control unit and sends output to an output device.

Some basic arithmetic operations include addition, substraction, multiplication, division, increment, decrement, etc and logical operations includes bitwise AND, OR, NOT, bitwise shift, etc. It is also used as fundamental building block in other computing circuits such as GPUs, FPUs, etc.

Nowadays ALU itself is divided into two parts –

  • Arithmetic Unit (AU)
  • Logical Unit (LU)

What is CU?

Control Unit or CU is one of the fundamental components of CPU which controls the operations of processor. It finds and tells the most efficient way to perform an operation. All the hardware components of a computer system are managed by the control unit.

CU directs the flow of data between CPU and other devices connected to a computer system. It typically uses a binary decoder which converts coded instruction into time and control signals that directs the operation of other units like memory, ALU, I/O devices etc. It also helps and controls how hardware and software interact with each other on computer system.

Differnce between ALU and CU

The key difference between ALU and CU are given in the below table.


ALU and CU both are fundamental components of CPU. I hope you understand their functions and differences between them.

Now if you have a query or feedback then write us in the comments below.

Leave a Comment