Learn: The ALU - Arithmetic vs Logic

Welcome!Welcome back! You've already learned about the CPU's importance, the fetch-decode-execute cycle, and how registers work. Today, we'll explore the Arithmetic Logic Unit (ALU) and its role in processing instructions.

What is the ALU?The Arithmetic Logic Unit (ALU) is a critical part of the CPU that performs calculations and logical operations. It handles arithmetic (e.g., addition, subtraction) and logic (e.g., comparisons, AND, OR, NOT) to process data and make decisions.

Why is the ALU important?The ALU enables the CPU to handle mathematical operations and logical comparisons efficiently. Without it, the computer wouldn't be able to perform calculations or make decisions needed for running programs.

Arithmetic OperationsThe ALU performs arithmetic operations like addition, subtraction, multiplication, and division. For example, when a program adds two numbers, the ALU does the calculation.

Logical OperationsThe ALU also performs logical operations such as AND, OR, and NOT. These operations evaluate conditions, helping the CPU decide what to do next based on the data.

How does the ALU work?Instructions are sent from the Control Unit (CU) to the ALU. The ALU processes the data by performing either arithmetic or logical operations and sends the result to the Accumulator or other registers.

Inputs and Outputs of the ALUThe ALU receives data inputs from the Memory Data Register (MDR) or Accumulator. After processing, it sends the result to the Accumulator or back to memory.

Review Time!Great work! You've learned about the ALU, its role, and the operations it performs. Let's test your understanding with a few questions.