一种改进的基于Kogge-Stone结构的并行前缀加法器

基于并行前缀算法的Kogge-Stone结构,通过改进其结构层次上的逻辑电路,提出一种改进的并行前缀加法器.与传统电路相比,该加法器不仅可以减小面积、功耗和延时,而且随着位宽的加大其优势更加明显,是适用于宽位的并行前缀加法器.     

改进结构的64位CMOS并行加法器设计与实现

介绍了一个用于高性能的微处理器和DSP处理器的快速64位二进制并行加法器.为了提高速度,改进了加法器结构,该结构大大减少了加法器各级门的延迟时间.基于改进的加法器结构,有效地使用动态复合门、时钟延迟多米诺逻辑和场效应管尺寸缩小技术,可以取得良好的电路性能.该加法器采用UMC 2.5V 0.25μm 1层多晶5层金属的CMOS工艺实现.完成一次加法运算的时间是700ps,比传统结构的加法器快20%;面积和功耗分别是0.16mm2和200mW@500MHz,与传统结构加法器相当.     

一种基于ALU单元的改进的三模冗余结构设计

对于传统的三模冗余结构(TMR),当其中两个模块发生失效时可能出现功能相同的情况,造成三模冗余失效.为了解决这一问题,针对ALU模块的结构特点提出了对操作数编码的方法到达三个模块差异化的效果,采用此方法后能100%的消除TMR同功能失效的问题,同时此方法相对于模块的差异化设计成本更低,效果更明显.     

改进结构的64位CMOS并行加法器设计与实现

介绍了一个用于高性能的微处理器和 DSP处理器的快速 6 4位二进制并行加法器 .为了提高速度 ,改进了加法器结构 ,该结构大大减少了加法器各级门的延迟时间 .基于改进的加法器结构 ,有效地使用动态复合门、时钟延迟多米诺逻辑和场效应管尺寸缩小技术 ,可以取得良好的电路性能 .该加法器采用 U MC 2 .5 V 0 .2 5μm 1层多晶 5层金属的 CMOS工艺实现 .完成一次加法运算的时间是 70 0 ps,比传统结构的加法器快 2 0 % ;面积和功耗分别是0 .16 m m2和 2 0 0 m W@5 0 0 MHz,与传统结构加法器相当 .     

32位稀疏树加法器的设计改进与实现

提出了一种改进进位运算的32位稀疏树加法器。在对现有稀疏树加法器使用的进位运算算子"o"进行深入探讨的基础上,对该算子的表达式做出了适当改进,去除了原算子中进位输入须为0的前提条件,同时保留了原算子适用于稀疏树进位结构的运算特性。采用该改进算子的32位稀疏树加法器可以并行地产生进位输入分别为0和1时的一对"和"输出,并可根据需要选择输出相应的结果。在1.2V130nm典型CMOS工艺条件下,经由HSPICE仿真,改进的32位稀疏树加法器的关键路径延迟为10.8FO4。结果表明,该加法器在运算能力得到扩充的同时,在运算速度方面也具有一定优势。     

一种基于复制码和汉明码的容错加法器

利用复制码(duplicated code)和汉明码(Hamming code)实现了一种新的容错加法器结构,对比之前提出的各种自检测(self-checking)加法器,该结构具有能在不需要重新计算的前提下,同时纠正出现在进位逻辑和求和逻辑上的软错误的特点.另一方面,该结构适用于各种利用基于行波进位的加法器结构,如旁路进位加法器、线性进位选择加法器和平方根进位选择加法器,并适合在汉明码校验的数据通路中工作.仿真结果表明,能有效地修正在进位逻辑上产生的多位软错误(soft error)和产生在求和逻辑上的单个软错误.     

64位超前进位对数加法器的设计与优化

设计一个应用于高性能微处理器的快速64位超前进位对数加法器.通过分析超前进位对数加法器原理,提出了改进四进制Kogge-Stone树算法的64位超前进位对数加法器结构,并结合使用多米诺动态逻辑、时钟延迟多米诺逻辑和传输门逻辑等技术来设计和优化电路.该加法器采用SMIC 0.18 μm CMOS工艺实现,在最坏情况下完成一次加法运算时间为486.1 ps,与相同工艺和相同电路结构采用静态CMOS实现相比,大大减少了加法器各级门的延迟时间,取得良好的电路性能.     

对数跳跃加法器的静态CMOS实现

介绍了一种32位对数跳跃加法器结构.该结构采用ELM超前进位加法器代替进位跳跃结构中的组内串行加法器,同ELM相比节约了30%的硬件开销.面向该算法,重点对关键单元进行了晶体管级的电路设计.其中的进位结合结构利用Ling算法,采用支路线或电路结构对伪进位产生逻辑进行优化;求和逻辑的设计利用传输管结构,用一级逻辑门实现"与-民或"功能;1.0μm CMOS工世实现的32位对数跳跃加法器面积为0.62mm2,采用1μm和0.25μm 工世参数的关键路径延迟分别为6ns和0.8ns,在100MHz下功耗分别为23和5.2mW.     

DSP芯片中全加器电路的优化设计

全加器在DSP芯片中是一个非常重要的逻辑器件,在DSP芯片内部存在着大量的加法器,通过对加法器的优化设计,可以使DSP芯片的性能得到提高.在本文中以CPL结构(Complementary pass transistor logic)加法器为基础提出了一种优化的加法器结构.并且通过HSPICE仿真,对28个晶体管的CMOS加法器、传统的CPL加法器和改进型的CPL加法器进行了比较.仿真的结果表明:改进型CPL加法器在功耗和延时等特性上比传统的28-T CMOS结构加法器和一般的CPL结构加法器有较大的提高.     

对数跳跃加法器的算法及结构设计

本文介绍一种新型加法器结构——对数跳跃加法器,该结构结合进位跳跃加法器和树形超前进位加法器算法,将跳跃进位分组内的进位链改成二叉树形超前进位结构,组内的路径延迟同操作数长度呈对数关系,因而结合了传统进位跳跃结构面积小、功耗低的特点和ELM树形CLA在速度方面的优势.在结构设计中应用Ling's算法设计进位结合结构,在不增加关键路径延迟的前提下,将初始进位嵌入到进位链.32位对数跳跃加法器的最大扇出为5,关键路径为8级逻辑门延迟,结构规整,易于集成.spectre电路仿真结果表明,在0.25μmCMOS工艺下,32位加法器的关键路径延迟为760ps,100MHz工作频率下功耗为5.2mW.     

Time redundancy and gate sizing soft error-tolerant based adder design

In this paper, we propose an efficient and promising soft error tolerance approach for arithmetic circuits with high performance and low area overhead. The technique is applied for designing soft error tolerant adders and is based on the use of a fault tolerant C-element connecting a given adder output to one input of the C-element while connecting a delayed version of that output to the second input. It exploits the variability of the delay of the adder output bits, in which the most significant bits (MSBs) have longer delay than the least significant bits (LSBs), by adding larger delay to the LSBs and smaller delay to the MSBs to guarantee full fault tolerance against the largest pulse width of transient error (soft error) for the available technology with minimum impact on performance. To guarantee fault protections for transistors feeding outputs with smaller added delay, the technique utilizes transistor scaling to ensure that the injected fault pulse width is less than the added delay of the second output of the C-element. Simulation results reveal that the proposed technique takes precedence over other techniques in terms of failure rate, area overhead, and delay overhead. The evaluation experiments have been done based on simulations at the transistor level using HSPICE to take care of temporal masking combined with electrical masking. In comparison to TMR, the technique achieves 100% reliability with 31% reduction in area overhead without impacting performance in the case of a 32-bit adder, and 42% reduction in area overhead and 5% reduction in performance overhead in the case of a 64-bit adder. While our proposed technique achieves area reduction of 4.95% and 9.23% in comparison to CE-based DMR and Feedback-based DMR techniques in the case of a 32-bit adder, it achieves area reduction of 19.58% and 23.24% in the case of a 64-bit adder.     

量子三值全加器设计

量子多值加法器是构建量子多值计算机的基本模块.通过认真分析三元域上加法的运算规则及带进位加法的真值表,通过设置扩展三值Toffoli门的控制条件有效实现一位加法在各种情况下的进位,利用三值Feynman门实现一位加法的求和运算,由此设计出一位量子三值全加器,再利用进位线将各位量子全加器连接起来构造出n位量子三值全加器.与同类电路相比,此量子全加器所使用的辅助线及量子代价都有所减少.     

全加器功能及应用的仿真设计分析

加法运算是数字系统中最基本的算术运算.为了能更好地利用加法器实现减法、乘法、除法、码制转换等运算,提出用Multisim虚拟仿真软件中的逻辑转换仪、字信号发生器、逻辑分析仪,时全加器进行功能仿真设计、转换、测试、分析,强化Multisim的使用,并通过用集成全加器74LS283实现两个一位8421码十进制数的减法运算,...     

Majority Logic Mapping for Soft Error Dependability

This work proposes the use of analog majority gates to implement combinational circuits that are intrinsically tolerant to transient faults. A new type of voter circuit, that uses some knowledge from the analog design arena is proposed, together with a new mapping approach to implement circuits given their input/output table. This new mapping approach is shown to compare favorably against a classic mapping. The implementation and validation of an adder circuit, using conventional triple modular redundancy (TMR), the classic mapping, and the proposed solution are analyzed, in order to confirm that the shown technique is indeed fault tolerant, and has advantages in terms of area and performance when compared to TMR. Finally, implementations of a subset of the ISCAS 85 benchmark circuits using TMR with the analog voter and the proposed approach are compared and the results analyzed.     

Self-repairing adder using fault localization

In this paper we propose an area-efficient self-repairing adder that can repair multiple faults and identify the particular faulty full adder. Fault detection and recovery has been carried out using self-checking full adders that can diagnose the fault based on internal functionality, independent of a fault propagated through carry. The idea was motivated by the common design problem of fault propagation due to carry in various approaches by self-checking adders. Such a fault can create problems in detecting the particular faulty full adder, and we need to replace the entire adder when an error is detected. We apply our self-checking full adder to a carry-select adder (CSeA) and show that the resulting self-checking CSeA consumes 15% less area compared to the previously proposed self-checking CSeA approach without fault localization. After observing fault localization with reduced area overhead, we utilize the self-checking full adder in constructing a self-repairing adder. It has been observed that our proposed self-repairing 16-bit adder can handle up to four faults effectively, with an 80% probability of error recovery compared to triple modular redundancy, which can handle only a single fault at a time.     

一种新型全加器结构的设计

全加器是算术运算的基本单元，设计结构简单的全加器有利于缩小数字自理芯片的面积。根据最新的ＸＯＲ门结构设计了一种新的全加器，这种结构的一位全加器只用２０只ＭＯＳ管，对这种新的全加器，用ＰＳＰＩＣＥ进行了晶体管级模拟。结果显示，这种新的全加器能正确完成加法器的逻辑功能。     

DLPA: Discrepant Low PDP 8-Bit Adder

This paper presents a new 8-bit adder circuit, called discrepant low PDP 8-bit adder (DLPA) based on three new full adder cells, which have been designed based on requirements of different positions in each 8-bit adder circuit. In order to design the full adder cells, a new and general method has been proposed aiming to achieve full-swing output and low number of transistors. The proposed adder along with several state-of-the-art adders from the literature have been extensively analyzed and compared together. The results revealed that the power-delay product of DLPA is almost more than 20 % less than that of other compared circuits.     

高性能全加器设计技术研究

文章讨论几种全加器的设计,并设计了一种基于数据选择器的全加器。通过HSPICE仿真,与其他结构的全加器进行比较,结果表明基于数据选择器的全加器在功耗与速度上比其他结构的全加器有较大提高。     

A novel multiplexer-based low-power full adder

The 1-bit full adder circuit is a very important component in the design of application specific integrated circuits. This paper presents a novel low-power multiplexer-based 1-bit full adder that uses 12 transistors (MBA-12T). In addition to reduced transition activity and charge recycling capability, this circuit has no direct connections to the power-supply nodes, leading to a noticeable reduction in short-current power consumption. Intensive HSPICE simulation shows that the new adder has more than 26% in power savings over conventional 28-transistor CMOS adder and it consumes 23% less power than 10-transistor adders (SERF and 10T ) and is 64% faster.