抗辐射高性能SRAM的设计技术研究

发布时间：2018-09-13 12:15

【摘要】：随着航空领域事业的飞速成长,静态随机存储器(Static Random Memory,SRAM)凭借着其功耗低、速度快的优点而被广泛应用到空间环境中,如宇宙飞船和空间卫星的控制系统等。太空环境中充满着多种具有辐射功能的粒子,其产生的辐射作用对电子设备上的存储器件造成不同程度的毁坏,对设备的性能和寿命产生严重影响。随着IC电路特征尺寸的降低和集成度的提高,对处在太空环境中的静态随机存储器提出了更多的要求,即在保证高速低耗的同时,还要具备抗粒子辐射的能力。本文分析了静态随机存储器的基本工作原理以及空间辐射效应对其产生的影响。辐射效应主要分为单粒子效应和总剂量效应,由于本文采用的是0.18um工艺,总剂量效应对器件的影响可以忽略不计。本文关于SRAM的抗辐射加固设计方案主要是对单粒子效应进行讨论的,先是研究分析了工艺级加固、系统级加固和电路级加固的三种加固方案的抗单粒子效应的工作机理,然后讨论方案的可行性及其实施的难易程度。存储单元作为SRAM最重要组成部分,对芯片的面积、稳定性、可靠性、功耗和速度等产生较大的影响,为此SRAM的抗辐射加固设计主要是针对存储单元进行的加固设计。双立互锁存储单元(Dual Interlocked Storage Cell,DICE)因其较强抗单粒子翻转能力而广泛应用于SRAM存储单元的加固中。但在读写状态下,DICE结构存储单元会发生抗单粒子效应失效的情况,为此,本文所设计的SRAM加固方案采用的是改进的DICE结构的存储单元——即采用读写分离的DICE结构;其次对SRAM的行列/译码电路、读/写预充电路、灵敏放大电路、读/写通路进行加固设计,并仿真验证各电路功能的正确性。最后基于0.18um工艺,完成了4K*32位SRAM整体电路读写功能验证、抗辐射性能验证、端口和时序功能验证等;完成存储单元和外围电路的基本功能仿真验证、抗辐射性能验证等。在1.8V电压条件下,仿真结果表明本文加固设计的SRAM能够在75MHz频率下正常工作,并保持良好的性能。
[Abstract]:With the rapid development of aviation industry, static random access memory (Static Random Memory,SRAM) is widely used in space environment, such as spacecraft and space satellite control system, because of its advantages of low power consumption and high speed. The space environment is full of many kinds of particles with radiation function. The radiation effects on the storage devices on electronic devices cause varying degrees of destruction, and have a serious impact on the performance and lifetime of the devices. With the decrease of the characteristic size and the improvement of the integration of IC circuits, the static random access memory in the space environment is required, that is, the ability to resist particle radiation while ensuring high speed and low consumption. In this paper, the basic working principle of static random access memory and the effect of space radiation on it are analyzed. The radiation effect is mainly divided into single particle effect and total dose effect. Since the 0.18um process is used in this paper, the total dose effect on the device can be ignored. In this paper, the single particle effect is mainly discussed in the design of radiation resistant reinforcement of SRAM. Firstly, the working mechanism of the three reinforcement schemes, which are process grade reinforcement, system level reinforcement and circuit level reinforcement, is studied and analyzed. Then the feasibility of the scheme and the degree of difficulty in its implementation are discussed. As the most important part of SRAM, memory cell has a great impact on the area, stability, reliability, power consumption and speed of the chip. Therefore, the design of anti-radiation reinforcement of SRAM is mainly aimed at the reinforcement design of memory cell. Double-stand interlocking memory cell (Dual Interlocked Storage Cell,DICE) is widely used in the reinforcement of SRAM memory cells because of its strong anti-single particle flip ability. However, under the condition of reading and writing, the memory cell of dice structure will fail against single particle effect. For this reason, the SRAM reinforcement scheme designed in this paper adopts the memory cell of the improved DICE structure, that is, the DICE structure which is separated from the read and write structure. Secondly, the column / decode circuit, read / write precharge circuit, sensitive amplifier circuit and read / write path of SRAM are designed, and the correctness of each circuit is verified by simulation. Finally, based on 0.18um process, the 4K*32 bit SRAM integrated circuit reading and writing function verification, anti-radiation performance verification, port and timing function verification, memory cell and peripheral circuit basic function simulation verification, anti-radiation performance verification and so on. At 1.8 V voltage, the simulation results show that the designed SRAM can work normally at 75MHz frequency and maintain good performance.
【学位授予单位】：江南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP333

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