What is the role of the arithmetic logic unit (ALU) in a microprocessor?
What is the role of the arithmetic logic unit (ALU) in a microprocessor?
404
05-Apr-2023
Updated on 06-Apr-2023
Krishnapriya Rajeev
06-Apr-2023The Arithmetic Logic Unit (ALU) of a microprocessor performs arithmetic and logical operations on binary data. The ALU is responsible for performing all the arithmetic operations, such as addition, subtraction, multiplication, and division, and logical operations such as AND, OR, and NOT.
ALU consists of the following components:
The ALU receives input data from the input registers and performs the requested arithmetic or logical operation based on the control signals received from the control unit. The result of the operation is then stored in the output register.
In addition to the above-mentioned basic components, modern ALUs may also include additional components such as barrel shifters for shifting data left or right, and carry lookahead circuits for improving the speed of addition and subtraction operations.
For example:
To perform addition, the ALU takes two binary numbers and adds them bit by bit, starting from the least significant bit and moving toward the most significant bit. If there is a carry bit generated during the addition operation, it is passed on to the next bit position for the next addition operation. The final result is stored in a register.