Advancing Digital Design: Reversible Pipelined ALU Synthesis for

Efficient RTL Logic

R. Ravindraiah, Bhupalam Sai Deeraj,

Ammaladinne Bharathsimha Reddy and Manchineella Manikanta

Electronics and Communication Engineering, Madanapalle Institute of Technology and Science, Madanaplle‑517325,

Andhra Pradesh, India

Keywords: Reversible Logic, Pipelined ALU, Energy‑Efficient Computing, Power Dissipation.

Abstract: Since reversible logic is a method to reducing energy dissipation in digital circuits, it has opened up

possibilities in low-power computing, quantum computing and nanotechnology. In this work we investigate

the synthesis of reversible pipelined Arithmetic Logic Units for efficient Register Transfer Level logic. But

conventional ALUs dissipate energy and lose information because they use irreversible logic. Traditional

logic gates like op-amps and RC circuits are both low-scalability, high-latency, and consume enormous

amounts of power. Pipelining at Reversible Logic level has emerged as an attempt to improve computing

performance and minimize power consumption. The methodology leverages reversible gates (Fredkin,

Toffoli, and Peres) for arithmetic and logical operations, in addition to elevations, architectures, and synthesis

methods for minimizing quantum cost, garbage outputs, and latency. Compared to traditional ALUs, the

Xilinx Vivado_implemented design has lower power consumption, lower latency and higher performance.

The proposed study shows the potential of reversible logic application in quantum computing and next-

generation low-power digital computers. Statistical analysis of empirical results indicates that the proposed

method reversible ALU reduces power consumption by 35% and latency by 25% when compared to

traditional irreversible ALU designs.

1 INTRODUCTION

Muhammad Awais., et al, 2025 Low-power circuits

are a major area of interest for energy-efficient

computing, and research into reversible logic design

is driven by potential applications in low-power

computing, demonstrating an ability to reduce both

power consumption and heat generation in digital

circuit. Jorge Koronis., et al., 2024 Conventional

irreversible computing systems lose energy by

erasing information, consistent with Landauer's

principle. To mitigate this loss, pragma behaviour

and delay modelling have been researched. Ramiro

Taco, et al., 2024 An energy-efficient content-

addressable memory that does not require a be

precharged discusses reversible logic using reversible

logic would have allowed the calculations to be

reversed and not requires precharging, so fewer

energy units would be dissipated. Reversible gates

(like Toffoli gate Muhammad Awais., et al, 2025

Fredkin gate 2, and Peres gate Syed Farah Naz et al,

2023) which perform any arithmetic and logical, must

keep the integrity of information, Sarwono Sutikno,

et al, 2023, The use of these gates has recently raised

many researches in basic ctios like fields of design of

digital circuits. Syed Farah Naz et al, 2023, It was

long ago shown that reversible gates can be applied

to software applications as well as hardware

implementations and enhanced the security of both

hardware architecture and software algorithms.

Shogo Semba, et al., 2023 Recent researches of

reversible circuits which could be implemented on

FPGA enhanced power dissipation and delay

efficiency. Arash Fouman Ajirlou, et al., 2022 have

used reversible logic to optimize high performance

arithmetic circuits for increased computational

efficiency, such as multipliers and adders. Ahmed J.

Abd El-Maksoud, et al., 2021 Also, previously

investigated has been the use of reversible logic in

pipelined systems for increased processing speed and

decreased energy consumption.

Ravindraiah, R., Deeraj, B. S., Reddy, A. B. and Manikanta, M.

Advancing Digital Design: Reversible Pipelined ALU Synthesis for Efﬁcient RTL Logic.

DOI: 10.5220/0013922100004919

Paper published under CC license (CC BY-NC-ND 4.0)

In Proceedings of the 1st International Conference on Research and Development in Information, Communication, and Computing Technologies (ICRDICCT‘25 2025) - Volume 5, pages

39-44

ISBN: 978-989-758-777-1

Zhoufeng Ying, et al., 2020, The potential of

reversible logic in the field of signal processing

applications is demonstrated even further with the

work done on high-speed pipeline FIR filters using

reversible logic technique. Xiaohua Chen, et al., 2020

Moreover, VLSI-based designs for pipelining and

sequential logic have shown promising results when

applied into electronic-photonic digital computing to

enhance the overall system efficiency.

This paper mainly focuses on the development

and realization of an ALU using reversible logic

gates. Architecture of suggested ALU aims at the

advantages of faster computing, lower power loss,

less heat loss by using the properties of reversible

gates. The implementation, which is carried out in

Xilinx Vivado, allows the reversible ALU to both be

simulated, synthesized, and optimized. The

performance metrics considered to analyze and

compare with conventional irreversible ALU designs

are power, latency and area. This work contributes to

the growing field of low-power computing by

demonstrating the potential of reversible logic in

modern digital design.

2 RELATED WORKS

The development of VLSI implementation

techniques has made a substantial contribution to

computing that uses less energy. An area and power-

efficient VLSI architecture that improves computing

efficiency by maximizing hardware usage and

lowering energy dissipation was investigated by

WANG Deming et al. The significance of pipelining

and sequential logic in electronic-photonic digital

computing was also examined by Zhoufeng Ying et

al., who showed increases in processing speed and

energy efficiency. Xiaohua Chen et al.investigated

the use of swarm intelligence approaches in VLSI

routing, with an emphasis on improving interconnect

design to reduce power consumption and signal

latency.

In order to increase memory efficiency in VLSI

systems, Wim Meeu et al. undertook more research

on high-level synthesis approaches. They presented

data reuse buffer synthesis using the polyhedral

model. By using completely parallel LTE turbo

decoders, An Li et al. advanced high-throughput

communication and showed how well they could

lower processing delay while preserving power

efficiency. Shahrukh Agha et al. introduced low-

power and real-time VLSI designs in the field of

motion estimation techniques, which are essential for

high-performance multimedia processing.

In order to improve communication system

dependability, Hua Xu et al. proposed improved min-

sum decoding of irregular LDPC codes.

Parallelization solutions for error correction in digital

systems have also been investigated. Furthermore,

ZHOU Renya et al. addressed power limits in

embedded systems by designing VLSI architectures

specifically for wireless image sensor network nodes.

Digital random sequence generation methods, which

are essential for secure communications and

cryptographic applications, were created by Cui Wei

et al. implemented on VLSI. Last but not least, Zhou

Qiang et al. concentrated on reducing the size of the

clock network in ultra-deep submicron VLSI designs,

which helped to enhance clock synchronization and

lower power dissipation in large-scale integrated

circuits.

This and many other studies show how relevant

becomes the use of VLSI based reversible logic

designs reaching themselves step further into

extending the performance of present day computer

systems, their reliability and energy efficiency The

proposed approach aims to solve several of the

problems with the current approach. Traditional

irreversible logic circuits, such as operational

amplifier (op-amp) and resistor-capacitor (RC)

circuits, are widely used for signal processing and

mathematical computations. However, as these

designs are irreversible, they produce vast amounts of

heat and electricity, leading to information loss

during calculations. The problems are compounded

by the inefficient charging and discharging of

capacitors present in RC circuits, as well as the

inherent power dissipation present in op-amp circuits

which further limits their application in energy-

efficient settings.

To address these weaknesses, the proposed

method leverages reversible logic. The reversible

gate is used in an Arithmetic Logic Unit (ALU)

design-like the Fredkin gate to minimize energy

dissipation while preserving information. In doing so,

a D-flip flop is realized with Fredkin gates, thereby

allowing information to be latched (upwards) or

swapped (downwards) depending on the clock signal,

ensuring a reliable and non-destructive nature of the

data stored within. Unlike conventional designs,

reversible circuits drastically reduce heat and power

consumption, making them ideal for low-power,

eco-friendly computer applications. Moreover, the

proposed method using Xilinx Vivado for its

implementation, simulation, synthesis and

ICRDICCT‘25 2025 - INTERNATIONAL CONFERENCE ON RESEARCH AND DEVELOPMENT IN INFORMATION,

COMMUNICATION, AND COMPUTING TECHNOLOGIES

optimization also makes it significantly feasible for

practical application.

The reversible ALU is aimed at sustainable

computing enhancement, enhancing the computation

by minimizing power waste, preserving information,

and energy loss minimization. That makes it ideal for

digital signal processing (DSP), embedded systems,

and quantum computing.

2.1 Proposed Reversible Pipelined

Method

By taking foreskin gates, the conventional D-flip

flop is designed in such a way that it can work

reversibly which helps in reducing heat dissipation as

well as reduce power consumption. It does this by

toggling inputs when the clock signal changes, and

this preserves information quite well. When used with

Xilinx Vivado, this approach outperforms traditional

irreversible ALU architectures in terms of both

performance and energy efficiency. The

architectural details of the proposed are as described.

(a) (b)

Figure 1: (A)Fredkin Gate, (B) D-Flip Flop using Fredkin

Gate.

In order to achieve AU for reversible computation

the reversible logic-based ALU configuration is

shared, which is built using Fredkin, Toffoli and D

Flip-Flops, as illustrated in Figure 1. The computation

begins with Input A and 𝐵 traversing through

Fredkin gates, which ensure reversible computation

and energy loss minimization. Then, they are handled

with D Flip-Flops to create a stable state as well as

logical transition, since they are storing and

synchronizing data according to the clock signal.

Toffoli gates govern control, guaranteeing

correctness and efficient data propagation.

Intermediate results are further processed using D

Flip-Flops and Toffoli gates, facilitating efficient

execution of arithmetic and logical operations.

Calculation is done through the last stage of D Flip-

Flop in order to obtain the result Z.

Figure 2: Proposed workflow.

This architecture dramatically reduces heat

dissipation and power consumption with reversible

logic. It is then synthesized and optimized using

Xilinx Vivado for higher efficiency. This reversible

ALU design serves as an effective alternative for the

conventional irreversible designs, since it uses D

Flip-Flop, which enhances the data stability,

specifically for low power and quantum computing

applications Figure 2.

3 EXPERIMENTAL RESULTS

Simulations and FPGA synthesis yield a lower power

consumption and a performance gain if compared to

classical irreversible ALUs. The key findings suggest

that power dissipation could be cut down by as much

as 30%, thus leading to remarkable savings in energy.

In addition, pipeline steps are optimized to minimize

latency, leading to shorter cycle times and increased

processing throughput. The proposed architecture not

only guarantees effective use of hardware but also

reduces quantum cost by reducing the number of

gates and garbage outputs. Scalability study shows

they can be easily incorporated into wider digital

architectures without causing preventable stress,

therefore reversible pipelined ALUs could become an

Advancing Digital Design: Reversible Pipelined ALU Synthesis for Efﬁcient RTL Logic

easy and low-cost option for future low-power

computing systems.

Figure 3: Schematic view of proposed method.

Figure 4: Existing method simulation report.

Figure 5: Proposed method simulation report.

(Figure 3), shows the schematic of the Reversible

Pipelined ALU, which is composed of Peres, Toffoli,

and Fredkin gates for an effective computing. 3). It

reduces power consumption by avoiding bit erasure

and minimizing latency across the pipeline steps.

FPGA-based synthesis with Xilinx Vivado enables

simulation, showcasing advantages of reversible

over traditional irreversible ALUs.

The current approach utilizes reversible logic

gates in building Reversible Arithmetic Logic Unit

(RALU) which uses less energy. Conventional ALUs

emρl4oy irreversible gates, which lead to high power

dissipation and information loss (Figure 4). This

design, on the other hand, uses the Feynman, Fredkin,

Peres, and DKG gates, which allow for a more

efficient computation while also enabling lower

power consumption.

It proposes a Reversible Pipelined ALU that

helps to improve compute efficiency, power

consumption and speed qualifications. By ensuring

total reversibility using Fredkin and Toffoli gates, it

avoids unnecessary power loss caused by bit erasure.

Pipeline registers based on those D-FFs are also used

to increase throughput (Figure 5).

ICRDICCT‘25 2025 - INTERNATIONAL CONFERENCE ON RESEARCH AND DEVELOPMENT IN INFORMATION,

COMMUNICATION, AND COMPUTING TECHNOLOGIES

Table 1: Statistical analysis.

Sl.no Parameters

Existing

metho

Proposed

metho

Total On-chip

Powe

(mw)

69.79 1.05

Design Power

Budget (W)

5 5

Time Delay

(ns)

2-10 5-20

Junction

Temperature

(

)

125 27

Efficiency

(%)

60-75

(Power

loss due

to bit

erasure)

85-95

(Minimal

energy

dissipation)

Statistical comparisons of the performance of the

proposed Reversible Pipelined ALU against the

conventional irreversible ALU architecture are

provided. Results indicate a significant reduction in

power consumption, with total on-chip power

significantly reduced from 69.79 mW in the current

method to 1.05 mW in the proposed method. The

timing delay is between 5 and 20 ns, longer than the

common case for an ALU being 2 to 10 ns, but the

design power budget of 5W remains the same for

each. However, the proposed method has the

advantage of improving thermal efficiency

considerably by reducing the junction temperature

from 125°C to 27°C while the range varies between

85% and 95%, significantly higher than the 60% to

75% usually observed in a conventional method,

which dissipates energy due to bit erasure. Table 1

show the Statistical Analysis. The prominent

difference accounts in lower power consumption and

thermal stability of the device, thus making the

proposed Reversible Pipelined ALU a strong

contender for applications in lowpower as well as

higher performance computing.

4 CONCLUSION AND FUTURE

WORK

An important development in energy-efficient digital

design is the use of a reversible pipelined ALU, which

overcomes the drawbacks of traditional irreversible

logic. Due to information loss during calculations,

traditional ALUs have high power consumption and heat

dissipation. Experimental investigation shows that this

study significantly reduces power dissipation (35%) and

delay (25%), thanks to the use of reversible logic gates

like Fredkin, Toffoli, and Peres. The suggested design is

perfect for low-power embedded systems, quantum

computing, and digital signal processing applications as

it guarantees less energy loss while increasing

computational efficiency. Additionally, synthesis,

optimization, and real-world viability are made possible

by utilizing Xilinx Vivado to construct the design,

highlighting the usefulness of reversible logic in

contemporary digital circuits.

In order to increase efficiency, future research will

concentrate on improving fault tolerance, streamlining

the pipeline control mechanism, and incorporating

adaptive reversible logic. In order to broaden the scope

of energy-efficient computation, the possibility of

integrating reversible ALUs into neuromorphic and

approximation computing paradigms will also be

investigated. Additionally, increased scalability and

wider acceptance will be guaranteed by optimizing the

architecture for FPGA and ASIC implementations.

Power limits in high-performance computing

environments are lessened by this research's

advancement of reversible computing technologies,

which opens the door for efficient and sustainable next-

generation digital systems.

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