ENERGY EFFICIENT IMPROVED 4-Bit ALU DESIGN

The 4-bit Arithmetic Logic Unit (ALU) is a fundamental component in digital systems, responsible for executing a range of arithmetic and logic operations on 4-bit binary inputs. This ALU design methodology outlines the construction of a 4-bit ALU capable of per- forming operations such as addition, subtraction, bitwise AND, OR, XOR, and bit-shifting (left and right). The architecture utilizes a 4-bit adder/subtractor for arithmetic operations, implementing two’s complement for subtraction. Logic operations are handled through standard logic gates (AND, OR, XOR), while shifting operations are facilitated using shift registers. Control signals, typically a 3-bit in- put, direct the ALU to select the desired operation, with multiplexers employed to choose be- tween different operation results. In addition to the primary computation, the ALU generates flags for zero detection, carry-out, and overflow, providing feedback on the result of operations. This design provides a comprehensive solution for arithmetic and logical computation, essential for various digital processing tasks. Keywords: Arithmetic Logic Unit (ALU), digital logic circuits, combinational logic, multiplexers, Verilog HDL.