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Global interconnects in VLSI complexity single flux quantum systems

Published: 14 December 2020 Publication History

Abstract

On-chip signal routing has become an issue of growing importance in modern VLSI complexity single flux quantum (SFQ) systems. In this paper, different routing methods for these systems are described. The routing methods include either passive transmission lines (PTLs) or Josephson transmission lines (JTLs) as interconnects. Driving multiple SFQ gates is also a challenging issue in automated layout and clock tree synthesis (CTS) due to the limited fanout of SFQ gates. To support multiple fanout, splitters are used to distribute multiple SFQ pulses. These splitters require significant area, delay, and power. In this paper, several area and power efficient splitters are proposed for large scale SFQ integrated circuits. A primary issue within a long SFQ interconnect is resonance effects due to the imperfect match between the PTLs and Josephson junctions. A repeater insertion methodology for long interconnect to reduce and manage these resonance effects is also described. Summarizing, guidelines and tradeoffs appropriate for automated layout and synthesis are described for driving long and short interconnect in VLSI complexity SFQ systems.

References

[1]
K. K. Likharev and V. K. Semenov, "RSFQ Logic/Memory Family: A New Josephson-Junction Technology for Sub-Terahertz-Clock-Frequency Digital Systems," IEEE Transactions on Applied Superconductivity, vol. 1, no. 1, pp. 3--28, March 1991.
[2]
V. K. Semenov, Y. A. Polyakov, and S. K. Tolpygo, "New AC-Powered SFQ Digital Circuits," IEEE Transactions on Applied Superconductivity, vol. 25, no. 3, pp. 1--7, June 2015.
[3]
K. Gaj, Q. P. Herr, V. Adler, A. Krasniewski, E. G. Friedman, and M. J. Feldman, "Tools for the Computer-Aided Design of Multigigahertz Superconducting Digital Circuits," IEEE Transactions on Applied Superconductivity, vol. 9, no. 1, pp. 18--38, March 1999.
[4]
C. J. Fourie, "Digital Superconducting Electronics Design Tools - Status and Roadmap," IEEE Transactions on Applied Superconductivity, vol. 28, no. 5, pp. 1--12, August 2018.
[5]
W. Chen, A. V. Rylyakov, V. Patel, J. E. Lukens, and K. K. Likharev, "Rapid Single Flux Quantum T-Flip Flop Operating up to 770 GHz," IEEE Transactions on Applied Superconductivity, vol. 9, no. 2, pp. 3212--3215, June 1999.
[6]
D. K. Brock, "RSFQ Technology: Circuits and Systems," International Journal of High Speed Electronics and Systems, vol. 11, no. 1, pp. 307--362, March 2001.
[7]
T. Jabbari, G. Krylov, S. Whiteley, E. Mlinar, J. Kawa, and E. G. Friedman, "Interconnect Routing for Large Scale RSFQ Circuits," IEEE Transactions on Applied Superconductivity, vol. 29, no. 5, August 2019.
[8]
S. K. Tolpygo, V. Bolkhovsky, T. J. Weir, A. Wynn, D. E. Oates, L. M. Johnson, and M. A. Gouker, "Advanced Fabrication Processes for Superconducting Very Large-Scale Integrated Circuits," IEEE Transactions on Applied Superconductivity, vol. 26, no. 3, pp. 1--10, April 2016.
[9]
A. Shukla, D. Kirichenko, A. Sahu, B. Chonigman, and A. Inamdar, "Investigation of Passive Transmission Lines for the MIT-LL SFQ5EE Process," IEEE Transactions on Applied Superconductivity, vol. 29, no. 5, pp. 1--7, February 2019.
[10]
"Predictive Technology Model (PTM)." [Online]. Available: http://ptm.asu.edu/
[11]
T. Jabbari, G. Krylov, S. Whiteley, J. Kawa, and E. G. Friedman, "Repeater Insertion in SFQ Interconnect," IEEE Transactions on Applied Superconductivity, vol. 30, no. 8, December 2020.
[12]
D. E. Kirichenko, S. Sarwana, and A. F. Kirichenko, "Zero Static Power Dissipation Biasing of RSFQ Circuits," IEEE Transactions on Applied Superconductivity, vol. 21, no. 3, June 2011.
[13]
N. K. Katam and M. Pedram, "Timing Characterization for Static Timing Analysis of Single Flux Quantum Circuits," IEEE Transactions on Applied Superconductivity, vol. 29, no. 6, p. 1--8, September 2019.
[14]
B. Dimov, V. Todorov, V. Mladenov, and F. H. Uhlmann, "The Josephson Transmission Line as an Impedance Matching Circuit," WSEAS Transactions on Circuits and Systems, vol. 3, no. 5, p. 1341--1346, December 2003.
[15]
S. N. Shahsavani, A. Shafaei, and M. Pedram, "A Placement Algorithm for Superconducting Logic Circuits based on Cell Grouping and Super-cell Placement," Proceedings of the IEEE Design, Automation Test in Europe Conference, vol. 29, pp. 1465--1468, March 2018.
[16]
R. N. Tadros and P. A. Beerel, "A Robust and Tree-Free Hybrid Clocking Technique for RSFQ circuits---CSR Application," Proceedings of the International Superconductive Electronics Conference, pp. 1--4, June 2017.
[17]
N. Kito, K. Takagi, and N. Takagi, "A Fast Wire-Routing Method and an Automatic Layout Tool for RSFQ Digital Circuits Considering Wirelength Matching," IEEE Transactions on Applied Superconductivity, vol. 28, no. 4, p. 1--5, June 2018.
[18]
N. Katam, A. Shafaei, and M. Pedram, "Design of Multiple Fanout Clock Distribution Network for Rapid Single Flux Quantum Technology," Proceedings of the IEEE Asia and South Pacific Design Automation Conference, pp. 384--389, February 2017.
[19]
S. N. Shahsavani and M. Pedram, "A Minimum-Skew Clock Tree Synthesis Algorithm for Single Flux Quantum Logic Circuits," IEEE Transactions on Applied Superconductivity, vol. 29, no. 8, December 2019.
[20]
Y. Hashimoto, S. Yorozu, Y. Kameda, A. Fujimaki, H. Terai, and N. Yoshikawa, "Design and Investigation of Gate-to-Gate Passive Interconnections for SFQ Logic Circuits," IEEE Transactions on Applied Superconductivity, vol. 15, no. 3, pp. 3814--3820, September 2005.
[21]
M. Tanaka, N. N. T. Kondo, T. Kawamoto, Y. Yamanashi, Y. Kamiya, A. Akimoto, A. Fujimaki, H. Hayakawa, N. Yoshikawa, and H. Terai, "Demonstration of a Single-Flux-Quantum Microprocessor using Passive Transmission Lines," IEEE Transactions on Applied Superconductivity, vol. 15, no. 2, pp. 400--404, June 2005.
[22]
S. Razmkhah and A. Bozbey, "Design of the Passive Transmission Lines for Different Stripline Widths and Impedances," IEEE Transactions on Applied Super-conductivity, vol. 26, no. 8, pp. 1--6, December 2016.
[23]
Y. Hashimoto, S. Yorozu, Y. Kameda, and V. K. Semenov, "A Design Approach to Passive Interconnects for Single Flux Quantum Logic Circuits," IEEE Transactions on Applied Superconductivity, vol. 13, no. 2, pp. 535--8, June 2003.
[24]
T. Jabbari, G. Krylov, S. Whiteley, J. Kawa, and E. G. Friedman, "Global Signaling for Large Scale RSFQ Circuits," Proceedings of the Government Microcircuit Applications and Critical Technology Conference, pp. 1--6, March 2019.
[25]
J. Bardeen, L. N. Cooper, and R. Schrieffer, "Theory of Superconductivity," Physical Review, vol. 108, no. 5, pp. 1175--1204, December 1957.
[26]
B. D. Josephson, "Possible New Effects in Superconductive Tunneling," Physics Letters, vol. 1, no. 7, pp. 251--253, July 1962.
[27]
T. Orlando and K. Delin, Foundations of Applied Superconductivity. Addison-Wesley, 1991.
[28]
"Niobium Process - Hypres, Inc." [Online]. Available: https://www.hypres.com/foundry/niobium-process/
[29]
T. V. Duzer, L. Zheng, X. Meng, C. Loyo, S. Whiteley, L. Yu, N. Newman, J. Rowell, and N. Yoshikawa, "Engineering Issues in High-Frequency RSFQ circuits," Physica C: Superconductivity, vol. 372, no. 1, pp. 1--6, August 2002.
[30]
O. Mukhanov, V. Semenov, and K. Likharev, "Ultimate Performance of the RSFQ Logic Circuits," IEEE Transactions on Magnetics, vol. 23, no. 2, pp. 759--762, March 1987.
[31]
T. V. Duzer and C. W. Turner, Principles of Superconductive Devices and Circuits, 2nd Edition, 1981.
[32]
H. Suhl, B. T. Matthias, and L. R. Walker, "Bardeen-Cooper-Schrieffer Theory of Superconductivity in the Case of Overlapping Bands," Physical Review Letters, vol. 3, no. 12, pp. 552--554, December 1959.
[33]
"Stony Brook RSFQ Cell Library." [Online]. Available: http://www.physics.sunysb.edu/Physics/RSFQ/Lib/PB/msl.html
[34]
T. Jabbari, G. Krylov, J. Kawa, and E. G. Friedman, "Splitter Trees in SFQ Circuits," IEEE Transactions on Applied Superconductivity (in submission).
[35]
O. A. Mukhanov, S. V. Rylov, D. V. Gaidarenko, N. B. Dubash, and V. V. Borzenets, "Josephson Output Interfaces for RSFQ Circuits," IEEE Transactions on Applied Superconductivity, vol. 7, no. 2, pp. 2826--2831, June 1997.
[36]
H. Suzuki, S. Nagasawa, K. Miyahara, and Y. Enomoto, "Characteristics of Driver and Receiver Circuits with a Passive Transmission Line in RSFQ Circuits," IEEE Transactions on Applied Superconductivity, vol. 10, no. 3, pp. 1637--1641, September 2000.
[37]
Y. Yamanashi, M. Tanaka, A. Akimoto, H. Park, Y. Kamiya, N. Irie, N. Yoshikawa, A. Fujimaki, H. Terai, and Y. Hashimoto, "Design and Implementation of a Pipelined Bit-Serial SFQ Microprocessor, CORE1β," IEEE Transactions on Applied Superconductivity, vol. 17, no. 2, pp. 474 -- 477, June 2007.
[38]
S. K. Tolpygo, V. Bolkhovsky, T. J. Weir, C. J. Galbraith, L. M. Johnson, M. A. Gouker, and V. K. Semenov, "Inductance of Circuit Structures for MIT LL Super-conductor Electronics Fabrication Process with 8 Niobium Layers," IEEE Transactions on Applied Superconductivity, vol. 25, no. 3, pp. 1--5, June 2015.
[39]
H. Suzuki, S. Nagasawa, K. Miyahara, and Y. Enomoto, "Characteristics of Driver and Receiver Circuits with a Passive Transmission Line in RSFQ Circuits," IEEE Transactions on Applied Superconductivity, vol. 10, no. 3, pp. 1637 -- 1641, September 2000.
[40]
L. Schindler, P. l. Roux, and C. J. Fourie, "Impedance Matching of Passive Transmission Line Receivers to Improve Reflections Between RSFQ Logic Cells," IEEE Transactions on Applied Superconductivity, vol. 30, no. 2, pp. 1--7, March 2020.
[41]
Y. Hashimoto, S. Yorozu, Y. Kameda, A. Fujimaki, H. Terai, and N. Yoshikawa, "Development of Passive Interconnection Technology for SFQ Circuits," IEICE Transactions on Electronics, vol. E88-C, no. 2, p. 198--207, Febuary 2005.
[42]
T. Ortlepp and F. H. Uhlmann, "Impedance Matching of Microstrip Inductors in Digital Superconductive Electronics," IEEE Transactions on Applied Superconductivity, vol. 19, no. 3, pp. 644 -- 648, June 2009.
[43]
V. Adler and E. G. Friedman, "Uniform Repeater Insertion in RC Trees," IEEE Transactions on Circuits and Systems I: Fundamental Theory and Applications, vol. 47, no. 10, pp. 1515 -- 1523, October 2000.
[44]
Y. I. Ismail, E. G. Friedman, and J. L. Neves, "Repeater Insertion in Tree Structured Inductive Interconnect," IEEE Transactions on Circuits and Systems II: Analog and Digital Signal Processing, vol. 48, no. 5, pp. 471 -- 481, May 2001.
[45]
V. Adler, C.-H. Cheah, K. Gaj, D. K. Brock, and E. G. Friedman, "A Cadence-Based Design Environment for Single Flux Quantum Circuits," IEEE Transactions on Applied Superconductivity, vol. AS-7, no. 2, pp. 3294--3297, June 1997.
[46]
S. R. Whiteley and J. Kawa, "Progress Toward VLSI-Capable EDA Tools for Superconductive Digital Electronics," Proceedings of the IEEE International Super-conductive Electronics Conference, pp. 1--3, February 2019.
[47]
E. S. Kuh and M. Marek-Sadowska, Global Routing in Layout Design and Verification. T. Ohtsuki, Ed., Amsterdam: North Holland, 1986.
[48]
Y. Kameda, S. Yorozu, and Y. Hashimoto, "A New Design Methodology for Single Flux-Quantum (SFQ) Logic Circuits Using Passive-Transmission-Line (PTL) Wiring," IEEE Transactions on Applied Superconductivity, vol. 17, no. 2, p. 1--5, June 2007.
[49]
S. N. Shahsavani, T. Lin, A. Shafaei, C. J. Fourie, and M. Pedram, "An Integrated Row-Based Cell Placement and Interconnect Synthesis Tool for Large SFQ Logic Circuits," IEEE Transactions on Applied Superconductivity, vol. 27, no. 4, p. 1302008, June 2017.
[50]
G. Krylov and E. G. Friedman, "Globally Asynchronous, Locally Synchronous Clocking and Shared Interconnect for Large Scale SFQ Systems," IEEE Transactions on Applied Superconductivity, vol. 29, no. 5, August 2019.
[51]
K. Gaj, Q. P. Herr, V. Adler, D. K. Brock, E. G. Friedman, and M. J. Feldman, "Towards a Systematic Design Methodology for Large Multi-Gigahertz Rapid Single Flux Quantum Circuits," IEEE Transactions on Applied Superconductivity, vol. 9, no. 13, pp. 4591--4606, September 1999.
[52]
K. Gaj, E. Friedman, M. Feldman, and A. Krasniewski, "A Clock Distribution Scheme for Large RSFQ Circuits," IEEE Transactions on Applied Superconductivity, vol. AS-5, no. 2, pp. 3320--3324, June 1995.
[53]
K. Gaj, E. Friedman, and M. Feldman, "Two-Phase Clocking for Medium to Large RSFQ Circuits," Proceedings of the International Superconductive Electronics Conference, pp. 302--304, June 1997.
[54]
K. Gaj, E. G. Friedman, and M. J. Feldman, "Choice of the Optimum Timing Scheme for RSFQ Digital Circuits," Proceedings of the International Workshop on High-Temperature Superconducting Electron Devices, pp. 39--40, May 1997.
[55]
T. Jabbari, J. Kawa, and E. G. Friedman, "H-Tree Clock Synthesis in RSFQ Circuits," Proceedings of the IEEE Baltic Electronics Conference, October 2020.
[56]
E. G. Friedman, "Clock Distribution Design in VLSI Circuits - an Overview," Proceedings of the IEEE International Symposium on Circuits and Systems, pp. 1475--1478, May 1993.
[57]
J. L. Neves and E. G. Friedman, "Topological Design of Clock Distribution Networks based on Non-Zero Clock Skew Specifications," Proceedings of the IEEE Midwest Symposium on Circuits and Systems, pp. 468--471, August 1993.
[58]
E. G. Friedman, "Clock Distribution Networks in Synchronous Digital Integrated Circuits," Proceedings of the IEEE, vol. 89, no. 5, pp. 665 -- 692, May 2001.
[59]
D. Velenis, E. G. Friedman, and M. C. Papaefthymiou, "A Clock Tree Topology Extraction Algorithm for Improving the Tolerance of Clock Distribution Networks to Delay Uncertainty," Proceedings of the IEEE International Symposium on Circuits and Systems, pp. 4.422--4.425, May 2001.
[60]
J. Rosenfeld and E. G. Friedman, "Design Methodology for Global Resonant H-Tree Clock Distribution Networks," IEEE Transactions on Very Large Scale Integration Systems, vol. 15, no. 2, pp. 135--148, February 2007.
[61]
L. Zheng, "High-Speed Rapid-Single-Flux-Quantum Multiplexer and Demultiplexer Design and Testing," University of California at Berkeley, pp. 13--24, August 2007.
[62]
R. S. Bakolo, "Design and Implementation of a RSFQ Superconductive Digital Electronics Cell Library," University of Stellenbosch, pp. 82--84, November 2011.
[63]
S. S. Meher, C. Kanungo, A. Shukla, and A. Inamdar, "Parametric Approach for Routing Power Nets and Passive Transmission Lines as Part of Digital Cells," IEEE Transactions on Applied Superconductivity, vol. 29, no. 5, pp. 1--7, August 2019.

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    cover image ACM Conferences
    SLIP '20: Proceedings of the Workshop on System-Level Interconnect: Problems and Pathfinding Workshop
    November 2020
    66 pages
    ISBN:9781450381062
    DOI:10.1145/3414622
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    • Andrew Kahng
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    Published: 14 December 2020

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    Author Tags

    1. single flux quantum
    2. super-conductive digital electronics
    3. superconductive integrated circuits

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