With the progress of the semiconductor industry,the resistive random-access memory（RAM） has drawn increasing attention.The discovery of the memristor has brought much attention to this study.Research has focused on ...With the progress of the semiconductor industry,the resistive random-access memory（RAM） has drawn increasing attention.The discovery of the memristor has brought much attention to this study.Research has focused on the resistive switching characteristics of different materials and the analysis of resistive switching mechanisms.We discuss the resistive switching mechanisms of different materials in this paper and analyze the differences of those mechanisms from the view point of circuitry to establish their respective circuit models.Finally,simulations are presented.We give the prospect of using different materials in resistive RAM on account of their resistive switching mechanisms,which are applied to explain their resistive switchings.展开更多
铁电存储器(ferroelectric random access memory,FRAM)是利用铁电材料可以自发极化,并且极化强度可以随外电场的作用而重新取向的特性为存储机制的一种非易失性存储器,它以其功耗低、读写速度快、耐久度高、抗辐射能力强等优点,成为存...铁电存储器(ferroelectric random access memory,FRAM)是利用铁电材料可以自发极化,并且极化强度可以随外电场的作用而重新取向的特性为存储机制的一种非易失性存储器,它以其功耗低、读写速度快、耐久度高、抗辐射能力强等优点,成为存储器领域最具潜力的产品之一。首先设计了一种1 kbit铁电存储芯片的整体架构,其次对其不同的工作时序进行了分析,再次对铁电存储器外围译码电路、驱动电路以及灵敏放大电路等电路模块进行了设计,每个设计过程包括电路设计、电路仿真和版图设计。由仿真结果可以看出,电路的选取均适用于铁电存储器的要求,为以后大容量、产品化的铁电存储器设计起到了基础性的指导作用。展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No. 60921062)
文摘With the progress of the semiconductor industry,the resistive random-access memory（RAM） has drawn increasing attention.The discovery of the memristor has brought much attention to this study.Research has focused on the resistive switching characteristics of different materials and the analysis of resistive switching mechanisms.We discuss the resistive switching mechanisms of different materials in this paper and analyze the differences of those mechanisms from the view point of circuitry to establish their respective circuit models.Finally,simulations are presented.We give the prospect of using different materials in resistive RAM on account of their resistive switching mechanisms,which are applied to explain their resistive switchings.
文摘铁电存储器(ferroelectric random access memory,FRAM)是利用铁电材料可以自发极化,并且极化强度可以随外电场的作用而重新取向的特性为存储机制的一种非易失性存储器,它以其功耗低、读写速度快、耐久度高、抗辐射能力强等优点,成为存储器领域最具潜力的产品之一。首先设计了一种1 kbit铁电存储芯片的整体架构,其次对其不同的工作时序进行了分析,再次对铁电存储器外围译码电路、驱动电路以及灵敏放大电路等电路模块进行了设计,每个设计过程包括电路设计、电路仿真和版图设计。由仿真结果可以看出,电路的选取均适用于铁电存储器的要求,为以后大容量、产品化的铁电存储器设计起到了基础性的指导作用。
文摘存储器是现代电子系统的核心器件之一,常用于满足不同层次的数据交换与存储需求.然而频率提高、时钟抖动、相位漂移以及不合理的布局布线等因素,都可能导致CPU对存储器访问稳定性的下降.针对同步动态随机读写存储器(synchronous dynamic random access memory,SDRAM)接口的时钟信号提出了一种自适应同步的训练方法,即利用可控延迟链使时钟相位按照训练模式偏移到最优相位,从而保证了存储器访问的稳定性.在芯片内部硬件上提供了一个可通过CPU控制的延迟电路,用来调整SDRAM时钟信号的相位.在系统软件上设计了训练程序,并通过与延迟电路的配合来达到自适应同步的目的:当CPU访问存储器连续多次发生错误时,系统抛出异常并自动进入训练模式.该模式令CPU在SDRAM中写入测试数据并读回,比对二者是否一致.根据测试数据比对结果,按训练模式调整延迟电路的延迟时间.经过若干次迭代,得到能正确访问存储器的延迟时间范围,即"有效数据采样窗口",取其中值即为SDRAM最优时钟相位偏移,完成训练后对系统复位,并采用新的时钟相位去访问存储器,从而保证读写的稳定性.仿真实验结果表明,本方法能迅速而准确地捕捉到有效数据采样窗口的两个端点位置,并以此计算出最佳的延迟单元数量,从而实现提高访问外部SDRAM存储器稳定性的目的.
