How is data processed by the arithmetic logic unit (ALU)?

The Arithmetic Logic Unit (ALU) processes data by performing arithmetic and logical operations on binary data.

The ALU is a fundamental building block of the central processing unit (CPU) in a computer. It is responsible for carrying out both arithmetic and logic operations. Arithmetic operations include basic calculations such as addition, subtraction, multiplication, and division. Logical operations, on the other hand, involve comparisons and decision-making tasks such as AND, OR, NOT, and XOR operations.

Data processing in the ALU begins when binary data is fed into it. This data is typically stored in registers, which are small storage locations within the CPU. The ALU takes this data and performs the required operation, which is determined by the instruction that the CPU has received. For example, if the instruction is to add two numbers, the ALU will take the binary data for these numbers from the registers, perform the addition, and then store the result back in a register.

The ALU is also capable of performing logical operations. These are used to make decisions based on certain conditions. For instance, an AND operation will return true if both of its inputs are true, while an OR operation will return true if either of its inputs is true. These operations are crucial for tasks such as decision making and flow control in programming.

The ALU is controlled by the control unit, another key component of the CPU. The control unit decodes the instructions that the CPU receives and then sends signals to the ALU to tell it which operation to perform. The ALU then executes the operation and sends the result back to the control unit, which then decides what to do with it.

In summary, the ALU processes data by performing arithmetic and logical operations on binary data. It takes this data from registers, performs the required operation, and then stores the result back in a register. The operations that the ALU performs are determined by the instructions that the CPU receives, which are decoded by the control unit.