Difference Between ALU and CU

The most essential component of a computer is the Central Processing Unit. It is popularly known as CPU. It is used to process instructions. The principal component of the CPU is the Arithmetic Logic Unit and Control Unit. In this article, we will learn what is the main difference between ALU and CU.

What is Arithmetic Logic Unit(ALU)?

ALU stands for Arithmetic Logic Unit. It is a very essential part of the CPU. It performs all the basic arithmetic (addition, subtraction, multiplication, and division) operations and logical operations. The ALU typically designed in such a way that it has direct input and output access to the random access memory (RAM). In modern computers, the ALU is itself is divided into two categories:

• Arithmetic Unit (AU)
• Logic Unit (LU)

Functions of ALU

Below are some functions of the Arithmetic Logic Unit(ALU).

• Input operands, adding operands, accumulated results, and shifting results can all be stored in the ALU.
• ALU subunits carried out gated circuits regulate the flow of data and the operations. A series of adding, subtracting, and shifting operations are used for division and multiplication.
• It performs arithmetic operations like addition, subtraction, multiplication, and division operations also it performs logical operations.

What is Control Unit(CU)?

CU stands for Control Unit. It is one of the fundamental parts of the CPU. The main work of the CU is to tell the most efficient method to work. It guides all the related operations to the individual parts of the processor. Some basic operation performed by it includes taking guidelines, controlling sequential execution, managing information stream in the correct course, directing and observing the time needed amid the preparing and taking care of different functions, etc. It controls the operations of the processor. It informs the ALU, I/O devices, and the RAM how to respond to the command that has been sent to the processor. A control unit directs the system and executes instructions entered by the user.

Functions of Control Unit(CU)

Below are some functions of CU.

• Controls how data is sent through the CPU’s various components.
• Receives and transmits control signals from other devices.
• Interprets commands, controls processor time, and regulates.
• Decode, fletch, carry out the order, and store the results, among other responsibilities.
• Interprets directions and directives.

Difference Between ALU and CU

Basis	Control Unit	Arithmetic Logic Unit
Abbreviation	CU	ALU
Work	It directs the system and executes the instructions entered by the user.  It directs and coordinates most of the operations in the computer.	To perform arithmetic operations, comparison operations, and other operations. It performs all the tasks to complete all those instructions.
Access	After the completion of the operation, the data gets deleted and it is not accessible.	Data is accessible at any time.
Relation	It is responsible to direct the system and execute the instructions.	It is responsible to perform all the tasks to complete the CU instruction.
Primary Condition needed	Equal-to conditions, Less-than condition, and greater than the state.	Loading of data and instructions that exist in the secondary memory to the main memory.
Dependency	No dependency on ALU.	ALU depends on CU for most of the time.

FAQs on Difference between ALU and CU

Q.1 What is ALU?

Answer:

Full form of ALU is Arithmetic Logic Unit. It executes all the basic arithmetic operations (addition, subtraction, multiplication, and division) and logical operations.

Q.2 What is CU?

Answer:

Full form of CU is Control Unit.CU controls the operations of instructions. The Control Unit tell the most efficient method to work. It guides all the related operations to the individual parts of the processor. To perform arithmetic operations, and other operations. It performs all the tasks to complete all those instructions.

Q.3 Explain the functions of the CU and ALU in the CPU of a computer?

Answer:

The ALU function is to performing all logical and arithmetic operations whereas the control unit function is to direct execute instructions. CU create communication between memory unit and ALU.

Q.4 Does CU depends on Arithmetic Logic Unit?

Answer:

No, The control unit does not depend on the arithmetic logic unit but the ALU depend on control unit for it’s functions.