Design and implementation of Arithmetic Logic Unit (ALU) using modified novel bit adder in QCA

Moore´s law states that the number of transistors that could be integrated into a single die would grow exponentially with time. Thus this causes increasing computational complexity of the chip and physical limitations of devices such as power consumption, interconnect will become very difficult. According to recent analysis the minimum limit for transistor size may be reached. Thus, it may not be possible to continue the rule of Moore´s law and doubling the clock rate for every three years. So in order to overcome this physical limit of CMOS-VLSI design an alternative approach is Quantum dot Cellular Automata (QCA). In ALU adder plays a vital role. In this survey a binary adder is taken for analysis and a new adder is designed based upon QCA technology. This modified novel bit adder is implemented into ALU structure. The aim of this proposed technique is that to reducing number of majority gates used in the design. This will lead to reduce number of QCA cells so that total area of ALU circuit can be minimized compare to previous designs. It also achieves reduced power consumption and high speed performances than all other existing ALU design which uses normal full adder.