基于CNFET的三值内容寻址存储器单元设计  

Design of Ternary CAM Cell Based on CNFET

作　　者：康耀鹏[1] 汪鹏君[1] 张会红[1] 李刚[1] KANG Yao-peng;WANG Peng-jun;ZHANG Hui-hong;LI Gang(Institute of Circuits and Systems,Ningbo University,Ningbo 315211,Zhejiang,China)

机构地区：[1]宁波大学电路与系统研究所,浙江宁波315211

出　　处：《华东理工大学学报（自然科学版）》2018年第5期724-729,共6页Journal of East China University of Science and Technology

基　　金：浙江省公益性技术应用研究计划项目(2016C31078);国家自然科学基金(61474068;61234002)

摘　　要：通过对三值静态随机存储器(Static Random Access Memory,SRAM)单元和数据比较电路结构以及碳纳米场效应晶体管(Carbon Nanotube Field Effect Transistor,CNFET)的研究,提出了基于CNFET的三值内容寻址存储器单元设计方案。首先利用CNFET阈值可调特性和开关信号理论设计三值缓冲器,采用反馈控制连接技术实现三值SRAM存储;然后结合三值SRAM单元和三值逻辑原理设计三值内容寻址存储器单元;最后实验验证,所设计的三值内容寻址存储器单元具有正确的逻辑功能,且与三态内容寻址存储器单元相比功耗延时积(Power-Delay Product,PDP)降低约83%。Content addressable memory(CAM)is a kind of memory with data search function that provides reading and writing ability by static random-access memory(SRAM),and is usually used in high-speed data search circuits.However,although many works have been recently reported on the ternary SRAM,few results have been obtained about ternary CAM.In nano-scale on CMOS,there are still many problems and challenges,such as short channel effect,increased drain power,and lower gate control ability.Carbon nano tube(CNT)is expecting to become the next important material in integrated circuit design,due to its excellent performance,especially,its ultra high electron mobility and super small size.These features make CNT as an ideal material of the preparation of high-performance field effect tube.Carbon nano tube field-effect transistor(CNFET)is a kind of material with adjustable threshold voltage,so it is suitable for designing multi-valued logic circuits.By researching CNFET,the structure of ternary SRAM cell,and data compare circuit,this paper proposes a design scheme on ternary content addressable memory cell with CNFET.First,the ternary buffer is designed by using switch-signal theory and CNFET.And then,the input and output are connected by transmission gate to achieve the function of SRAM cell.In addition,by combining the SRAM cell with ternary logic circuit,a ternary CAM cell is achieved.Finally,the experiment under Stanford University 32 nm CNFET standard model is made,which shows that the proposed CAM cell has the correct logic function.Moreover,compared with TCAM cell,the designed circuit has lower power-delay product,reducing about 83%.Especially,the TCAM can be only used to search binary data in the circuits,conversely,the proposed ternary CAM unit can be applied to the data lookup of ternary circuit.Hence,this proposed scheme could enrich the three-value memory design field and provide a promising direction for further design of large-capacity addressable memory.

关 键 词：CNFET 三值数据比较 CAM 三值逻辑 

分 类 号：TN334.3[电子电信—物理电子学]