The design of Quantum-dot CellularAutomata decimal adder

Abstract

Figure 1. QCA Cell and Wire II. QCA BASICSThe classical QCA cell and wire [16] are shown in fig. 1. Each QCA cell is composed of four quantum dots occupied by two electrons and separated by tunneling barriers. The electrons can tunnel between the dots, but not the cells. They are forced to occupy the cell coroner's positions due to Columbic repulsion to maximize their separation. This results in two stable configurations known as cell polarization P= +1 and P = -1. This configuration is used to represent binary logic where P = + 1 is used to represent the logic "1" and P = -1 is used to represent the binary logic "0". QCA operates by Coulombic interaction [16] that connects the state of one cell to the state of its neighbors. Thus, no electrical current is needed to transfer information. A QCA wire is created by an array of QCA cells where the neighboring QCA cells interact with each other which results in the information flow between them.in decimal arithmetic. With this revision currently in progress, it is likely that many high-end processors in the near future will perform decimal operations directly on decimal operations using dedicated decimal units that are much faster than the current decimal software packages [13].The addition operation is the basic operation in decimal arithmetic and it is carried out in hardware using Binary Coded Decimal adder also known as Decimal Adder. This adder is also the fundamental unit needed to design complex decimal units such as decimal floating point adders and multipliers. Thus, it is important to explore the decimal design in future nanotechnologies. To the best of our knowledge, this is the first design of QCA decimal adder using MVG. The reminder of this work is organized as follows. In Section II, we give some background material on QCA. The design of the proposed QCA decimal adder is presented in section III. Then discussed and analyzed in Section IV. This is followed by the paper conclusion.Abstract-Recently, there has been an increasing interest in hardware support for decimal arithmetic driven by the growing demands from financial and commercial applications. A crucial building block for decimal operations is the decimal adder. Thus, it is important to explore its design in future nanotechnologies. This work presents the first decimal adder design in Quantumdot Cellular Automata (QCA) nanotechnology using majority voting gates. The proposed one-digit QCA decimal full adder structure in this paper requires 27 majority voting gates and 16 inverters.