Superconducting Technology Assessment - nitrd

1.3.2 RSFQ ATTRIBUTES
Important attributes of RSFQ digital circuits include:
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■ Fast, low-power switching devices that generate identical single-flux-quantum data pulses.
■ Loss-less superconducting wiring for power distribution.
■ Latches that store a magnetic-flux quantum.
■ Low loss, low dispersion integrated superconducting transmission lines that support
“ballistic” data and clock transfer at the clock rate.
■ Cryogenic operating temperatures that reduce thermal noise and enable low power operation.
■ RSFQ circuit fabrication that can leverage processing technology and computer-aided design
(CAD) tools developed for the semiconductor industry.
Additional discussion of RSFQ technology basics can be found in Appendix D.
1.4 SUMMARY OF PANEL’S EFFORTS
The ITRS has identified RSFQ logic as the lowest risk of the emerging logic technologies to supplement CMOS
for high-end computing. The panel’s report:
■ Provides a detailed assessment of the status of RSFQ circuit and key supporting technologies.
■ Presents a roadmap for maturing RSFQ and critical supporting technologies by 2010.
■ Estimates the investment required to achieve the level of maturity required to initiate
development of a high-end computer in 2010.
TABLE 1-1. THE PANEL’S CONCLUSIONS:
– Although significant risk items remain to be addressed, RSFQ technology is an excellent candidate
for the high-speed processing components of petaflops-scale computers.
– Government investment is necessary because private industry has no compelling financial reason
to develop this technology for mainstream commercial applications.
– With aggressive federal investment (estimated between $372 and $437 million over five years),
by 2010 RSFQ technology can be brought to the point where the design and construction of an
operational petaflops-scale system can begin.