Research Of Design Methods Of The Read/Write Circuit Of Resistive Memory

As the memristor has many characteristics,such as smaller size,higher integration,lower power consumption,nonvolatile and so on,so,the resistive storage is the most promising application in the numerous application areas of the memristor.Therefore,it is a very important basic task to study the read and write operation of the memristor.This paper mainly research the read and write circuitries of the memristor,and the main contents related to this study are organized as follows:In chapter one,the background and the significance of this paper and the research status of memristor and its read/write circuit is introduced.Moreover,the research contents and the structure of this paper is also introduced briefly.In chapter two,the basic characteristics of memristor is briefly studied,including the definition and the physical realization,circuit characteristics,resistance variation model and the classification of memristor.Among these,the boundary migration model proposed by HP laboratory and the mathematical derivation of the charge-control model and the magnetic-control model is mainly researched.In chapter three,a new simple threshold model of memristor is proposed,based on the Zha window function.To be first,the linear model and the window function model of the HP model is introduced,among them,the window function model is emphatically studied,and the comparison of the advantages and disadvantages of several typical window functions is given.Moreover,two typical threshold model,TEAM model and Yakopcic model,is briefly introduced.Then,the Zha window function is improved in order to reduce the computational complexity,and add a threshold function to the improved window function to form a new window function,which is used in the simulation of this paper.Lastly,the SPICE model of memristor which is used in this paper is introduced and the corresponding code is given.In chapter four,a new read and write circuitry of binary value memristor is proposed.Based on the linear model,the read and write operation of the binary value memristor is studied.The three basic properties are introduced and simulated.Then,the logical state of the memristor is defined,and the rigorous mathematical derivation about the time that read and write operation need is given,and the pulse waveform width restrictions is also given.Lastly,some typical read and write circuits about the binary value memristor is researched,including the classical circuit and the circuit which is based on feedback.And a new circuit based on the threshold model is given,this circuit has many advantages,such as accurate write operation and simple read operation.The simulation result verify the correctness of this improved circuit.In chapter five,the read and write circuit of four-value memrirstor is designed.The binary memristor is transformed into four-value memristor by way of resistance division.The read circuit is constructed by four voltage compactors and 74HC148 priority encoder,the write circuit is constructed based on the feedback thinking,the circuit can make the final resistance of memristor tend to be the ideal value according to the pre-set circuit parameters.The simulation result show that the proposed read and write circuit can work correctly.