Discuss the role of ALU in a processor?

The arithmetic and logic unit (ALU) is the part of the processor that does all the calculations and the decisions on data.

It performs arithmetic operations such as add, subtract, increment and compare, and logic operations such as AND, OR, NOT, XOR and shifts. The control unit sends select signals that choose the operation. The ALU takes its operands from registers or the accumulator, produces the result, and sets status flags such as zero, carry, sign and overflow. The program uses these flags for branching.