Design Of Crossing With Fault Tolerance In Quantum-dot Cellular Automata

In recent years,with the continuous development of microelectronics technology,the size of devices has been further reduced.Quantum effects have been gradually manifested,such as high-density,high power consumption,complex wiring and crosstalk.Traditional microelectronics technology is facing many technological challenges.Therefore,the vast number of researchers are looking for new devices instead of traditional CMOS devices.In the past twenty years,many emerging technologies are emerging and developing rapidly.Quantum-dot Cellular Automata(QCA)is the most representative of many alternative devices.QCA provides a completely new way to code and transmit information.QCA circuit can simply realize adder,multiplier,trigger and memory in traditional circuit,so it has a very broad development prospect.In the field of nano devices,QCA defines a new device structure.For this new system design method,the most important feature is the transmission of information pipelining and the intersection of signal lines in the same plane.The key to achieve information transmission in the same plane is the design of crossover lines.The stability of the intersections directly determines the stability of the whole circuit.However,the existing crossover lines still have problems in stability,fault tolerance and transmission rate.In this paper,we study how to achieve a more stable,higher fault tolerance coplanar cross structure.This paper describes three kinds of cross coplanar crossing structure and a different surface structure,the four structures respectively by standard cellular and rotate cellular structure,by four clock,by seven clock and a multilayer QCA cell,the advantages and disadvantages of each scheme are analyzed.In this paper,on the basis of previous work,put forward a more stable,with the fault tolerance performance of dual clock cross coplanar structure,and through the analysis of the stability of the electrostatic potential energy between cellular and cellular electronics,the loss of cellular experiment to illustrate the fault-tolerant performance of new cross structure,interspersed with more the existing solutions and new cross cross program.The experimental data of transmission line cell number and fixed cell loss of cross points prove that the two transmission lines can improve the cross fault tolerance according to diagonal layout mode,so the output accuracy rate of the structure is still 100% when the cell loss rate reaches 33.33%.Finally,a two bit multiplier and adder is designed with the new cross structure,and the algorithm for clock placement in large circuits is given.