US 2020/0028512 A1 · JTL-BASED SUPERCONDUCTING LOGIC ARRAYS AND FPGAS

Abstract

Superconducting logic arrays (SLAs) and field-programmable gate arrays (FPGAs) that are based on Josephson transmission lines (JTLs) accommodate reciprocal quantum logic (RQL) compliant binary input signals and provide RQL-compliant output signals that are evaluations of generalized logic functions. Each JTL-based superconducting FPGA (JTLBSFPGA) incorporates multiple JTL-based SLAs (JTLBSLAs) connected together. Each JTLBSLA includes an array of software-programmable and/or mask-programmed logic cells that output products of inputs and cell states, such that the JTLBSLAs output evaluations of sum-of-products functions. New JTLBSLA logic cells are described, including some that provide programmable cell states via magnetic Josephson junctions (MJJs). JTLBSFPGAs provide area efficiency and clock speed advantages over CMOS FPGAs. Unlike SLAs based on Josephson magnetic random access memory (JMRAM), JTLBSLAs do not require word line drivers, flux pumps, or sense amplifiers. Because JTLBSLAs and JTLBSFPGAs are RQL-compliant, they can also include RQL gates connected within or between them, without signal conversion circuitry.

Claims20

Dependent claims

A Josephson-junction-based superconducting reciprocal quantum logic (RQL) cell circuit comprising:

a logic evaluation loop comprising:
a secondary inductor of a selection input transformer through which an RQL-compliant read selection signal is provided to the logic evaluation loop from a read selection Josephson transmission line (JTL);
a read data input from which an RQL-compliant read data signal is provided to the logic evaluation loop from a read data JTL;
and
an escape Josephson junction (JJ) configured to trigger or not to trigger so as to block the read data signal from propagating to an output JTL or to act as a superconducting short to pass the read data signal to the output JTL, respectively, based on bias conditions established by the read selection signal,
wherein the logic evaluation loop is configured to readout an RQL-compliant logical output signal based on the read selection signal and the read data signal.

3 more elements

A mask-programmable Josephson-transmission-line-based superconducting reciprocal quantum logic (RQL) cell circuit comprising:

a read data line comprising a first Josephson transmission line (JTL) arranged between a read data input and a read data output;
and
a read selection line arranged orthogonally to the read data line and comprising a second JTL arranged between a read selection input and a read selection output,
wherein the mask-programmable cell circuit is a pass-through cell configured to force a cell state of logical “0” such that a signal provided to the read data input is always propagated to the read data output.

1 more element

Dependencies are inferred from the claim text.

Jtl-based superconducting logic arrays and fpgas

Life of this patent

Jtl-based superconducting logic arrays and fpgas

Life of this patent

Abstract

Claims20