基于常规原理图方式的可逆逻辑描述与综合方法

发布时间：2018-01-29 09:15

本文关键词： 可逆逻辑电路经典逻辑门功能性描述和验证可逆算术运算单元等功能代换　出处：《东华大学》2016年硕士论文　论文类型：学位论文

【摘要】：随着众多学者日渐认可Landauer提出的计算过程的能量消耗与计算的可逆性有必然联系的理论,可逆逻辑电路因而被视为降低集成电路功耗和延续相关技术、产业发展的必由之路,吸引着科学界越来越多的关注。但由于可逆逻辑电路“诞生”不久,相关经验和知识奇缺,而且特点突出(即与常规电路差异较大),国内外有关研究尚于起步阶段,有关的理论体系和技术平台均远未成熟甚至空白。另一方面,常规(非可逆)逻辑设计经过长期发展,已形成相当成熟的理论体系和技术平台,特别是功能强大、使用方便的EDA(电子设计自动化)技术和工具。因此论文着重研究将常规逻辑设计移植,复用于可逆逻辑设计的方法,并依赖于成熟的EDA技术和工具实现基于常规原理图方式的可逆ALU算术运算单元的可逆描述验证。鉴于除“非门”外的传统逻辑门均不可逆,大多数可逆逻辑门均系重新定义、设计。其中常用的有CNOT门、Toffoli系列门和Fredkin门等。受可逆性约束,可逆逻辑电路和可逆门具有输入和输出在个数上相同,在组合上双射的特点,其对应功能表也是相互映射的可逆真值表。因为常规逻辑与可逆逻辑之间最大的差异具体体现在计算的可逆性上,但它们逻辑表达式所实现的功能本质上是相同的,因此,文中提出两种可逆逻辑电路的设计方法,第一种是利用常规逻辑门的组合,等功能地表达和替换可逆逻辑电路中的各种可逆逻辑门,进而利用EDA工具(Quaruts II)对可逆逻辑电路进行功能仿真验证;第二种是利用可逆逻辑门的组合,等功能地表达和替换常规逻辑电路中的各种常规逻辑门,进而根据成熟的、经过充分验证的常规逻辑电路(如利用EDA工具设计的多位ALU单元电路),转化成为等功能的可逆逻辑电路,从而实现较大规模、较复杂可逆逻辑电路的功能设计。运用上述两种方法结合人工修正,论文完成了可逆加法器、可逆减法器、可逆乘法器及可逆除法器的设计,从而完成了最基本的可逆ALU算术运算单元的功能设计。由于可逆加法器和可逆减法器皆是在全加器的基础上设计的,把原本两个独立设计的模块合并有效地兼顾实现加法和减法的功能。最终的仿真结果显示该可逆算术运算单元能够实现多位数的加法、减法和乘法功能,以及除法功能。在一定程度上,该论文的成果可为实现从现行常规逻辑到未来可逆逻辑的成果继承和平稳过渡提供研究资料和参考。
[Abstract]:With the increasing acceptance of Landauer's theory that the energy consumption of computing process is related to the reversibility of computation, many scholars have accepted that there is an inevitable relationship between the energy consumption and the reversibility of calculation. As a result, reversible logic circuits are regarded as reducing the power consumption of integrated circuits and extending related technologies. The only way to develop industry is attracting more and more attention from the scientific community. However, the reversible logic circuits are not long since the birth of reversible logic circuits. The relevant experience and knowledge are extremely scarce, and the characteristics are outstanding (that is, the difference with the conventional circuit is big, the domestic and foreign related research is still in the initial stage, the relevant theoretical system and technical platform are far from mature or even blank. On the other hand. After a long period of development, conventional (non-reversible) logic design has formed a quite mature theoretical system and technical platform, especially the powerful function. The paper focuses on the method of transplanting the conventional logic design to reversible logic design by using the convenient EDA (Electronic Design Automation) technology and tools. The reversible description verification of reversible ALU arithmetic unit based on conventional schematic diagram is realized based on mature EDA technology and tools. In view of the fact that the traditional logic gates except "non-gate" are not reversible. Most reversible logic gates are redefined and redesigned. Among them, CNOT gates, Toffoli series gates, Fredkin gates, etc., are subject to reversibility constraints. The reversible logic circuit and the reversible gate have the same number of inputs and outputs and bijection in combination. The corresponding function list is also a reversible truth table mapped to each other, because the biggest difference between conventional logic and reversible logic is the reversibility of calculation. However, the functions of their logical expressions are essentially the same. Therefore, two design methods of reversible logic circuits are proposed in this paper, the first is the combination of conventional logic gates. The reversible logic gates in reversible logic circuits are expressed and replaced with equal functions, and the reversible logic circuits are verified by EDA tools. The second is to use the combination of reversible logic gates and other functions to express and replace the conventional logic gates in the conventional logic circuits, and then according to the mature. The conventional logic circuit (such as the multi-bit ALU cell circuit designed with EDA tools), which has been fully verified, is transformed into a reversible logic circuit with equal functions, thus realizing a large scale. The design of reversible adder, reversible subtraction, reversible multiplier and reversible divider is completed by using the above two methods combined with manual correction. Thus the function design of the most basic reversible ALU arithmetic unit is completed, because the reversible adder and the reversible subtraction are designed on the basis of the full adder. The original two independently designed modules are combined to effectively realize the functions of addition and subtraction. Finally, the simulation results show that the reversible arithmetic unit can achieve the functions of multi-digit addition, subtraction and multiplication. To a certain extent, the results of this paper can provide research materials and references for the inheritance and smooth transition from the current conventional logic to the future reversible logic.
【学位授予单位】：东华大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TN791

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