32 × 32-Bit 4-Bit Bit-Slice Integer Multiplier for RSFQ Microprocessors

A design of a 32 × 32-bit 4-bit bit-slice integer multiplier for rapid single-flux quantum microprocessors is shown. The multiplier carries out both signed and unsigned multiplication. It is designed with synchronous concurrent-flow clocking and target frequency of 50 GHz using the AIST 1.0-μm Nb/AlO
_x
/Nb, nine-layer advanced process 2 fabrication technology with a critical current density of 10 kA/cm
²
. It consists of 56 885 Josephson junctions. The area is 12.00 × 6.65 mm
²
. The simulation results show correct operation with frequency of 50 GHz at the dc bias voltage of 2.5 mV. The throughput is 3.125 × 10
⁹
multiplications per second.