학술논문

Results From the ColdFlux Superconductor Integrated Circuit Design Tool Project
Document Type
Periodical
Source
IEEE Transactions on Applied Superconductivity IEEE Trans. Appl. Supercond. Applied Superconductivity, IEEE Transactions on. 33(8):1-26 Nov, 2023
Subject
Fields, Waves and Electromagnetics
Engineered Materials, Dielectrics and Plasmas
Libraries
Microprocessors
Fabrication
Computer architecture
Layout
Superconducting integrated circuits
Solid modeling
Compact model
electronic design automation tools
flux trapping
inductance extraction
moats
superconductor electronics (SCE)
Language
ISSN
1051-8223
1558-2515
2378-7074
Abstract
In five and a half years, the ColdFlux project under the IARPA SuperTools program pushed the boundaries of digital and analog superconductor electronic design automation (S-EDA) tools. The SuperTools program demanded significant beyond-state-of-the-art deliverables in four main areas: RTL synthesis, architectures, and verification; analog design and layout synthesis; physical design and test; and technology CAD and cell library design. Through the work of academic groups scattered over four continents, the ColdFlux effort forged into a powerful set of open-source and commercial S-EDA tools unlike any before, rivaled only by a commercial toolchain from Synopsys under the same SuperTools umbrella. We present an overview of the tools from where we started to the eventual project deliverables. These include powerful simulation and extraction engines, magnetic field and flux trapping analysis, advanced clocking methods, multi-chip interface extraction and verification, unified multi-layer design-rule compliant track blocks for automated place and route of both rapid single flux quantum (RSFQ) and adiabatic quantum-flux-parametron (AQFP) cells, models and tools for validation and test, multi-bit single flux quantum (SFQ) cells, architecture innovations for full CPU designs and more. Comprehensive cell libraries and a process design kit (PDK) were developed with the ColdFlux tools. The AQFP cell library features a logically rich collection of 80+ cells, including 3- and 5-input logic gates, signal-driving boosters, and refined RSFQ-to-AQFP interfaces, while the RSFQ library has 30+ cells. Finally, we discuss how the full toolchain enables and enhances the superconductor IC design process.