一种新型低冗余抗多节点翻转的加固D锁存器设计

在航空航天等高辐射领域中,电荷共享效应引起的多节点翻转(Multiple-Node Upset,MNU)在D锁存器中愈发频繁,其可严重影响电子系统的功能。虽然目前现有的抗MNU加固D锁存器能够对MNU进行容错恢复,但是其硬件开销非常大。为解决这一问题,本文设计了一种新型低冗余抗MNU的加固D锁存器。在TSMC 65nm CMOS工艺下对该锁存器时序及容错功能进行的仿真验证结果表明,与现有抗MNU锁存器相比,本文构造的加固锁存器不仅可恢复MNU,而且具有面积更小、功耗更低、传输时间更短的优点。     

SEU加固存储单元中的多节点翻转

使用3D器件模拟了SEU加固单元的多节点翻转(multiple node upset,MNU)问题.结果表明瞬时悬空节点和电荷横向扩散是MNU的关键原因.对比了MNU和不同存储单元之间的MBU(multiple bit upset),发现它们之间的特点存在较大差异.最后讨论了避免MNU的方法.     

两个低开销抗单粒子翻转锁存器

提出了两个抗单粒子翻转(SEU)的锁存器电路SEUT-A和SEUT-B。SEU的免疫性是通过将数据存放在不同的节点以及电路的恢复机制达到的。两个电路功能的实现都没有特殊的器件尺寸要求,所以都可以由小尺寸器件设计完成。提出的结构通过标准的0.18μm工艺设计实现并仿真。仿真结果表明两个电路都是SEU免疫的,而且都要比常规非加固的锁存器节省功耗。和传统的锁存电路相比,SEUT-A只多用了11%的器件数和6%的传输延时,而SEUT-B多用了56%的器件数,但获得了比传统电路快43%的速度。     

一种新型的抗辐射加固锁存器

Due to aggressive technology scaling, radiation-induced soft errors have become a serious reliability concern in VLSI chip design. This paper presents a novel radiation hardened by design latch with high single-eventupset （SEU） immunity. The proposed latch can effectively mitigate SEU by internal dual interlocked scheme. The propagation delay, power dissipation and power delay product of the presented latch are evaluated by detailed SPICE simulations. Compared with previous SEU-hardening solutions such as TMR-Latch, the presented latch is more area efficient, delay and power efficient. Fault injection simulations also demonstrate the robustness of the presented latch even under high energy particle strikes.     

一种双节点翻转加固的RS触发器

随着IC集成度的不断提高,电路中单粒子引起的多节点翻转现象愈加频繁。为了解决该问题,提出了一种可对两个电压节点翻转完全免疫的RS触发器电路。基于双互锁存储单元结构,设计了一个冗余度为4的前置RS触发器。将不相邻的两个输出节点连接到一个改进型C单元电路中,屏蔽了错误电压,最终输出电压不受单粒子翻转的影响。该RS触发器采用0.25 μm 2P4M 商用标准CMOS工艺实现。对RS触发器中任意两个电路节点同时分别注入两个单粒子事件,进行了抗单粒子翻转的可靠性验证。Spectre仿真结果表明,该RS触发器能完全对两个单粒子事件免疫。与已发表的辐射加固触发器相比,该触发器采用的晶体管个数减少了20.8%,功耗降低了21.3%。     

SEU 加固存储单元中的多节点翻转

使用3D器件模拟了SEU加固单元的多节点翻转(multiple node upset,MNU)问题.结果表明瞬时悬空节点和电荷横向扩散是MNU的关键原因.对比了MNU和不同存储单元之间的MBU(multiple bit upset),发现它们之间的特点存在较大差异.最后讨论了避免MNU的方法.     

一种抗单粒子多节点翻转的存储单元

为解决纳米CMOS工艺下单粒子多节点翻转的问题,提出了一种加固存储单元(RH-12T)。在Quatro-10T存储单元基础上对电路结构进行改进,使存“0”节点不受高能粒子入射的影响,敏感节点对的数目是晶体管双立互锁(DICE)存储单元的一半。基于敏感节点对分离和SET缩减原理,进行了加固存储单元版图设计。在相同设计方法下,该存储单元的敏感节点间距是DICE存储单元的3倍。抗SEU仿真结果表明,该存储单元具备单节点翻转全加固能力。全物理模型单粒子瞬态仿真结果表明,该存储单元的线性能量转移 (LET)翻转阈值为DICE存储单元的2.8倍,能有效缓解单粒子多节点翻转的问题。     

一种低开销加固锁存器的设计

针对单粒子翻转问题,设计了一种低开销的加固锁存器。在输出级使用钟控C单元,以屏蔽锁存器内部节点的瞬态故障;在输出节点所在的反馈环上使用C单元,屏蔽输出节点上瞬态故障对电路的影响;采用了从输入节点到输出节点的高速通路设计,延迟开销大幅降低。HSPICE仿真结果表明,相比于FERST,SEUI,HLR,Iso-DICE锁存器,该锁存器的面积平均下降23.20%,延迟平均下降55.14%,功耗平均下降42.62%。PVT分析表明,该锁存器的性能参数受PVT变化的影响很小,性能稳定。     

SEU加固存储单元多节点翻转的准三维数值模拟

为了深入了解SEU加固存储单元中多节点翻转的内部电荷收集及电压变化机制,采用准三维模拟工具MEDICI,对DIED加固单元进行器件/ 电路的混合模拟.结果表明,瞬时浮制节点和电荷的横向扩散是多节点翻转的关键原因.还研究其他加固单元多节点翻转的特点,并给出了避免多节点翻转的方法.     

A four-interleaving HBD SRAM cell based on dual DICE for multiple node collection mitigation

A 4-interleaving cell of 2-dual interlocked cells (DICE) is proposed, which reduces single event induced multiple node collection between the sensitive nodes of sensitive pairs in a DICE storage cell in 65 nm technology. The technique involves the 4-interleaving of dual DICE cells at a layout level to meet the required spacing between sensitive nodes in an area-efficient manner. Radiation experiments using a 65 nm CMOS test chip demonstrate that the LETth of our 4-interleaving cell of dual DICE encounters are almost 4× larger and the SEU cross section per bit for our proposed dual DICE design is almost two orders of magnitude less compared to the reference traditional DICE cell.     

High performance energy efficient radiation hardened latch for low voltage applications

Energy efficiency is considered to be the most critical design parameter for IoT and other ultra low power applications. However, energy efficient circuits show a lesser immunity against soft error, because of the smaller device node capacitances in nanoscale technologies and near-threshold voltage operation. Due to these reasons, the tolerance of the sequential circuits to SEUs is an important consideration in nanoscale near threshold CMOS design. This paper presents an energy efficient SEU tolerant latch. The proposed latch improves the SEU tolerance by using a clocked Muller- C and memory elements based restorer circuit. The parasitic extracted simulations using STMicroelectronics 65 nm CMOS technology show that by employing the proposed latch, an average improvement of ∼40% in energy delay product (EDP), is obtained over the recently reported latch. Moreover, the proposed latch is also validated in a TCAD calibrated PTM 32 nm framework and PTM 22 nm CMOS technology nodes. In 32 nm and 22 nm technologies, the proposed latch improves the EDP ∼12% and 59% over existing latches respectively.     

Modeling and simulation of single-event effect in CMOS circuit

This paper reviews the status of research in modeling and simulation of single-event effects (SEE) in digital devices and integrated circuits. After introducing a brief historical overview of SEE simulation, different level simulation approaches of SEE are detailed, including material-level physical simulation where two primary methods by which ionizing radiation releases charge in a semiconductor device (direct ionization and indirect ionization) are introduced, device-level simulation where the main emerging physical phenomena affecting nanometer devices (bipolar transistor effect, charge sharing effect) and the methods envisaged for taking them into account are focused on, and circuit-level simulation where the methods for predicting single-event response about the production and propagation of single-event transients (SETs) in sequential and combinatorial logic are detailed, as well as the soft error rate trends with scaling are particularly addressed.     

一种提高反熔丝 FPGA 容错能力的新方法

针对反熔丝FPGA中反熔丝单元的开路故障,提出了一种提高反熔丝 FPGA容错能力的新方法．该方法通过对VPR布线算法的改进,在FPGA布线时预留更多的对称布线资源以便在故障发生时用于容错处理．实验结果表明,当FPGA布线资源固定时,该方法在布线阶段有效增加了对称线段的预留量,预留量平均可增加30．4％,最高可达100％;当预留量达到100％时,FPGA的单个反熔丝故障都可以通过容错消除该故障．     

40 nm CMOS工艺下的低功耗容软错误锁存器

为了降低集成电路的软错误率,该文基于时间冗余的方法提出一种低功耗容忍软错误锁存器。该锁存器不但可以过滤上游组合逻辑传播过来的SET脉冲,而且对SEU完全免疫。其输出节点不会因为高能粒子轰击而进入高阻态,所以该锁存器能够适用于门控时钟电路。SPICE仿真结果表明,与同类的加固锁存器相比,该文结构仅仅增加13.4%的平均延时,使得可以过滤的SET脉冲宽度平均增加了44.3%,并且功耗平均降低了48.5%,功耗延时积(PDP)平均降低了46.0%,晶体管数目平均减少了9.1%。     

一种新的适用于算法容错的加权校验和编码方案

基于算法的容错或算法容错是提高实时数字信号处理和其他大规模计算环境中并行系统可靠性的有效方案，本文讨论了一种新的具有高纠错能力的广义加权校验和编码方法，并进一步给出了快速的检测的检错纠错算法，最后讨论了新的编码方案在容错运算中的应用。     

一种65 nm CMOS低功耗加固SRAM单元

提出了12管低功耗SRAM加固单元。基于堆叠结构,大幅度降低电路的泄漏电流,有效降低了电路功耗。基于两个稳定结构,可以有效容忍单粒子翻转引起的软错误。Hspice仿真结果表明,与相关加固结构相比,该结构的功耗平均下降31.09%,HSNM平均上升19.91%,RSNM平均上升97.34%,WSNM平均上升15.37%,全工作状态下均具有较高的静态噪声容限,表现出优秀的稳定性能。虽然面积开销平均增加了9.56%,但是,读时间平均下降14.27%,写时间平均下降18.40%,能够满足高速电子设备的需求。     

面向航空环境的多时钟单粒子翻转故障注入方法

随着新型电子器件越来越多地被机载航电设备所采用,单粒子翻转(Single Event Upset, SEU)故障已经成为影响航空飞行安全的重大隐患。首先,针对由于单粒子翻转故障的随机性,该文对不同时刻发生的单粒子翻转故障引入了多时钟控制,构建了SEU故障注入测试系统。然后模拟真实情况下单粒子效应引发的多时间点故障,研究了单粒子效应对基于FPGA构成的时序电路的影响,并在线统计了被测模块的失效数据和失效率。实验结果表明,对于基于FPGA构建容错电路,采用多时钟沿三模冗余(Triple Modular Redundancy, TMR) 加固技术可比传统TMR技术提高约1.86倍的抗SEU性能;该多时钟SEU故障注入测试系统可以快速、准确、低成本地实现单粒子翻转故障测试,从而验证了SEU加固技术的有效性。     

A New Approach to Software-Implemented Fault Tolerance

A new approach for providing fault detection and correction capabilities by using software techniques only is described. The approach is suitable for developing safety-critical applications exploiting unhardened commercial-off-the-shelf processor-based architectures. Data and code duplications are exploited to detect and correct transient faults affecting the processor data segment, while control flow instruction duplication is used for detecting and correcting faults affecting the code segment. Results coming from extensive fault injection campaigns showed the effectiveness and the limitations of the method.