PROJECT TITLE :

Three Parallel Generation of a 4-bit M-Sequence Using Single-Flux-Quantum Digital Circuits

ABSTRACT:

Maximum-length sequences (M-sequences) are referred to as pseudo-random numbers generated with relatively simple digital circuits. In this paper, we present one-flux-quantum digital circuit that generated three output bits of a four-bit M-sequence in one clock operation. The circuit comprised 3 clocked exclusive-or gates, one delay flip-flop, three dc/SFQ converters (for set, reset, and low-frequency clock signals), and three SFQ/dc converters (for three parallel outputs), all of which were integrated on a superconducting Nb chip. A 10-GHz clock generator was additionally implemented for high-speed testing. The total range of Nb/AlOx/Nb Josephson junctions was 568. Verilog simulation demonstrated correct circuit operation with a 20-GHz clock, which corresponded to the generation rate of 60 Gb/s. The measurement was disbursed in an exceedingly liquid helium tub. Low-speed testing with a one-kHz clock demonstrated periodic signals of three parallelized four-bit M-sequence. We tend to also confirmed that the outputs were properly shifted when thirteen clock signals of 10 GHz were fed between 2 one-kHz clock signals.