Question

Which of the following operations is NOT typically performed by the Arithmetic Logic Unit?

• A. Logical AND, OR and NOT
• B. Comparison of values
• C. Addition and Subtraction
• D. Data transfer between RAM and storage

Hint:

ALU performs:
• Arithmetic operations
• Logical operations
• Comparisons Memory transfers are controlled by the Control Unit and I/O systems, not by the ALU.

Answer 1

The Correct Option is D

Concept: The Arithmetic Logic Unit (ALU) is one of the most important components of the CPU. It is responsible for carrying out arithmetic calculations and logical operations on data received from memory or registers. The ALU works under the supervision of the Control Unit and processes numerical as well as logical data.

Step 1: Understand the arithmetic functions of ALU.
The term Arithmetic refers to mathematical calculations. Examples include: \[ \text{Addition},\quad \text{Subtraction},\quad \text{Multiplication},\quad \text{Division} \] Therefore, addition and subtraction are performed by the ALU.

Step 2: Understand the logical functions of ALU.
The ALU also performs logical operations used in decision-making. Examples include: \[ \text{AND},\quad \text{OR},\quad \text{NOT},\quad \text{XOR} \] Hence logical AND, OR and NOT are ALU functions.

Step 3: Understand comparison operations.
The ALU compares values to determine whether: \[ A>B,\quad A<B,\quad A=B \] Such comparisons are essential in programming and processor execution. Thus comparison operations are also performed by the ALU.

Step 4: Analyze data transfer operations.
Transferring data between RAM and storage devices is handled by:
• Memory Controller
• Input/Output System
• Control Unit The ALU does not directly perform data transfer operations. \[ \boxed{\text{Data transfer between RAM and storage}} \] Hence, option (D) is correct.