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Summary: A multiplier, as a key component in many different applications, is a time‐consuming, energy‐intensive computation block. Approximate computing is a practical design paradigm that attempts to improve hardware efficacy while keeping computation quality satisfactory. A novel multicolumn 3,3:2 inexact compressor is presented in this paper. It takes three partial products from two adjacent columns each for rapid partial product reduction. The proposed inexact compressor and its derivatives enable us to design a high‐speed approximate multiplier. Then, another ultra‐fast, high‐efficient approximate multiplier is achieved by utilizing a systematic truncation strategy. The proposed multipliers accumulate partial products in only two stages, one fewer stage than other approximate multipliers in the literature. Implementation results by the Synopsys Design Compiler and 45 nm technology node demonstrate nearly 11.11% higher speed for the second proposed design over the fastest existing approximate multiplier. Furthermore, the new approximate multipliers are applied to the image processing application of image sharpening, and their performance in this application is highly satisfactory. It is shown in this paper that the error pattern of an approximate multiplier, in addition to the mean error distance and error rate, has a direct effect on the outcomes of the image processing application. [ABSTRACT FROM AUTHOR]

The history of ternary adders goes back to more than 6 decades ago. Since then, a multitude of ternary full adders (TFAs) have been presented in the literature. This article conducts a review of TFAs so that one can be familiar with the utilised design methodologies and their prevalence. Moreover, despite numerous TFAs, almost none of them are in their simplest form. A large number of transistors could have been eliminated by considering a partial TFA instead of a complete one. According to our investigation, only 28.6% of the previous designs are partial TFAs. Also, they could have been simplified even further by assuming a partial TFA with an output carry voltage of 0 V or VDD. This way, in a single‐VDD design, voltage division inside the Carry generator part would have been eliminated and less power dissipated. As far as we have searched, there are only three partial TFAs with this favourable condition in the literature. Additionally, most of the simulation setups in the previous articles are not realistic enough. Therefore, the simulation results reported in these papers are neither comparable nor entirely valid. Therefore, the authors got motivated to conduct a survey, elaborate on this issue, and enhance some of the previous designs. Among 84 papers, 10 different TFAs (from 11 papers) are selected, simplified, and simulated in this article. Simulation results by HSPICE and 32 nm carbon nanotube FET technology reveal that the simplified partial TFAs outperform their original versions in terms of delay, power, and transistor count. [ABSTRACT FROM AUTHOR]

This study presents a new scalable mathematical approach for designing compressors with any arbitrary number of inputs using multi‐input threshold gates, behaving as exclusive‐OR (XOR). This study relates the theoretical concept to hardware implementation. The methodology is exploited for 3:2, 7:3, and 15:4 compressors, and then implemented by using input capacitors (or resistors) and threshold detectors. The transistor‐level realisation of 3:2 and 7:3 compressors is simulated by using Synopsys HSPICE and 32 nm Carbon Nanotube Field Effect Transistors technology. The proposed methodology benefits from the parallel operation of threshold detectors. Therefore, by increasing the number of inputs, the delay parameter does not increase dramatically. The layout views are also provided in order to be able to compare area for the 3:2 compressors with both capacitor and resistor networks. [ABSTRACT FROM AUTHOR]

In this paper, a new voltage mirror circuit by using carbon nanotubes (CNTs) technology is presented. This circuit is specifically proposed for the application of duplicating multiple‐valued and fuzzy dynamic random access memories. The given structure prevents any voltage drop for the capacitor inside the memory cell. As a result, any fanout circuit can be driven. The new structure can be utilised for different multiple‐valued logic systems without a change. The unique characteristics of carbon nanotube field effect transistor (CNFET) technology are exploited in this paper to meet the desired design goals. It demonstrates the potentials of CNFET technology in a realistic very large‐scale integration application. The proposed design is highly tolerant to DCNT variation and it is also immune to misaligned CNTs. Simulation results demonstrate that it provides sufficient driving capability with reasonable accuracy. [ABSTRACT FROM AUTHOR]