Electronics/ALU

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Arithmetic and Logic Unit[edit]

Introduction[edit]

The Arithmetic and Logic Unit are not a single entity, but are actually composed of two separate units whose operation is highly dependent on the Select Input(S).

This input is a one-bit input that will decide whether to route the binary variables to the Arithmetic or to the Logic Circuit.

Arithmetic Unit[edit]

Handles basic operations such as Addition and Subtraction. The Multiplication and Division operations are dependent on the basic operations and Bit-Shifting. The Multiply and Divide operations can also be implemented using Hardwired / Microprogrammed Control.

Logic Unit[edit]

The Logic unit is a Hardware Unit implemented for performing basic operations such as AND, OR, NAND and NOT. A particular logical operation is selected using a 4:1 Demultiplexer.

The results of all the operations are routed into a data bus for memory addressing.

further reading[edit]