Computer Science – Computer architecture | e-Consult

The Arithmetic Logic Unit (ALU) is a crucial component of the CPU responsible for performing arithmetic and logical operations. It's the part of the CPU that actually carries out the calculations specified by the instruction. The ALU receives data from registers and memory, performs the requested operation, and then stores the result back in a register or memory.

The ALU operates based on the control signals received from the Control Unit. These control signals specify which operation the ALU should perform (e.g., addition, subtraction, AND, OR). The ALU has various internal circuits to perform these operations.

Example: Consider the instruction to add the contents of register A and register B and store the result in register C. The ALU would receive the values from registers A and B, perform the addition operation, and then store the sum in register C. The Control Unit would send the appropriate control signals to the ALU to indicate that an addition operation is required and to specify the input and output registers.