Majority Gate-Based Feedback Latches for Adiabatic Quantum Flux Parametron Logic

Tsuji, Naoki; Takeuchi, Naoki; Yamanashi, Yuki; Ortlepp, Thomas; Yoshikawa, Nobuyuki

doi:10.1587/transele.e99.c.710

Cited by 10 publications

(4 citation statements)

References 17 publications

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“…In previous studies [16,18,19], we operated AQFP circuits in a three-phase excitation mode using three ac current sources, in which excitation currents are provided with a phase separation of 120°. In this study, we design new AQFP logic cells so that they can operate in a four-phase excitation mode with a fewer number of ac current sources for high-frequency and low-latency implementation.…”

Section: Four-phase Excitation Schemementioning

confidence: 99%

“…In a previous study [16], we built an AQFP cell library using the 2.5 kA cm −2 Nb standard process (STP2) [17] provided by National Institute of Advanced Industrial Science and Technology (AIST). Using this cell library, we designed and demonstrated several AQFP logic circuits, including an 8 bit CLA [16], a feedback latch [18], and a 21k-junction circuit [19], which is the largest AQFP circuit ever fabricated using STP2.…”

Section: Introductionmentioning

confidence: 99%

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Adiabatic quantum-flux-parametron cell library designed using a 10 kA cm⁻²niobium fabrication process

Takeuchi

Nagasawa

China

et al. 2017

Supercond. Sci. Technol.

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103

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Adiabatic quantum-flux-parametron (AQFP) logic is an energy-efficient superconductor logic with zero static power consumption and very small switching energy. In this paper, we report a new AQFP cell library designed using the AIST 10 kA cm−2 Nb high-speed standard process (HSTP), which is a high-critical-current–density version of the AIST 2.5 kA cm−2 Nb standard process (STP2). Since the intrinsic damping of the Josephson junction (JJ) of HSTP is relatively strong, shunt resistors for JJs were removed and the energy efficiency improved significantly. Also, excitation transformers in the new cells were redesigned so that the cells can operate in a four-phase excitation mode. We described the detail of HSTP and the AQFP cell library designed using HSTP, and showed experimental results of cell test circuits.

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Section: Four-phase Excitation Schemementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Adiabatic quantum-flux-parametron cell library designed using a 10 kA cm⁻²niobium fabrication process

Takeuchi

Nagasawa

China

et al. 2017

Supercond. Sci. Technol.

Self Cite

103

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“…Memory structures are needed for the IDI and RFX stages of MANA. We created an adiabatic latch by connecting AQFP logic gates in a short four-phase feedback loop similar to the academic latches composed of NAND or NOR gates [33]. This gate-level implementation of an AQFP latch has an enable input which is asserted on the same clock phase as the input data when we want to write into the latch.…”

Section: Memorymentioning

confidence: 99%

MANA: A Monolithic Adiabatic iNtegration Architecture Microprocessor Using 1.4-zJ/op Unshunted Superconductor Josephson Junction Devices

Ayala

Tanaka

Saito

et al. 2021

IEEE J. Solid-State Circuits

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We conducted the first successful demonstration of an adiabatic microprocessor based on unshunted Josephson junction (JJ) devices manufactured using a Nb/AlO x /Nb superconductor IC fabrication process. It is a hybrid of RISC and dataflow architectures operating on 4-b data words. We demonstrate register file R/W access, ALU execution, hardware stalling, and program branching performed at 100 kHz under the cryogenic temperature of 4.2 K. We also successfully demonstrated a highspeed breakout chip of the microprocessor execution units up to 2.5 GHz. We use a logic primitive called the adiabatic quantumflux-parametron (AQFP), which has a switching energy of 1.4 zJ per JJ when driven by a four-phase 5-GHz sinusoidal ac-clock at 4.2 K. These demonstrations show that AQFP logic is capable of both processing and memory operations and that we have a path toward practical adiabatic computing operating at highclock rates while dissipating very little energy.

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“…However, for the generous use of the advantage of the AQFP circuits, reduction of the energy consumption of the memories is essential. Although flip-flops based on AQFP circuits have been proposed in previous study [15][16][17], their circuit area is not small enough for making high-density large-scale memories. Any RAMs for large-scale memories compatible with AQFP circuits have not been realized yet.…”

Section: Introductionmentioning

confidence: 99%

A random-access-memory cell based on quantum flux parametron with three control lines

Takayama

Takeuchi

Yamanashi

et al. 2018

J. Phys.: Conf. Ser.

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Majority Gate-Based Feedback Latches for Adiabatic Quantum Flux Parametron Logic

Cited by 10 publications

References 17 publications

Adiabatic quantum-flux-parametron cell library designed using a 10 kA cm⁻²niobium fabrication process

Adiabatic quantum-flux-parametron cell library designed using a 10 kA cm⁻²niobium fabrication process

MANA: A Monolithic Adiabatic iNtegration Architecture Microprocessor Using 1.4-zJ/op Unshunted Superconductor Josephson Junction Devices

A random-access-memory cell based on quantum flux parametron with three control lines

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Majority Gate-Based Feedback Latches for Adiabatic Quantum Flux Parametron Logic

Cited by 10 publications

References 17 publications

Adiabatic quantum-flux-parametron cell library designed using a 10 kA cm−2niobium fabrication process

Adiabatic quantum-flux-parametron cell library designed using a 10 kA cm−2niobium fabrication process

MANA: A Monolithic Adiabatic iNtegration Architecture Microprocessor Using 1.4-zJ/op Unshunted Superconductor Josephson Junction Devices

A random-access-memory cell based on quantum flux parametron with three control lines

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Product

Resources

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Adiabatic quantum-flux-parametron cell library designed using a 10 kA cm⁻²niobium fabrication process

Adiabatic quantum-flux-parametron cell library designed using a 10 kA cm⁻²niobium fabrication process