Title :
A subnanosecond Josephson 16-bit ALU
Author :
Kotani, Seigo ; Fujimaki, Norio ; Imamura, Takeshi ; Hasuo, Shinya
Author_Institution :
Fujitsu Ltd., Atsugi, Japan
fDate :
4/1/1988 12:00:00 AM
Abstract :
The design and characteristics of a Nb based Josephson 16-bit arithmetic logic unit (ALU) for use as a major component of a practical Josephson microprocessor are discussed. The ALU has 900 gates and uses dual-rail logic to perform 12 functions. One of the simplest algorithms, the ripple-carry method, is used. Experiments confirmed that ALU functions operated correctly. The critical path delay time was 860 ps for a 10.1-mW power dissipation. Average values estimated from experiments are 9.2 ps for the gate delay and 113 μW for the gate power dissipation. The results demonstrate that development of a Josephson microprocessor is feasible
Keywords :
Josephson effect; microprocessor chips; superconducting logic circuits; 10.1 mW; 113 muW; 12 functions; 16 bit; 860 ps; 9.2 ps; Josephson 16-bit ALU; Nb junctions; arithmetic logic unit; critical path delay; dual-rail logic; gate delay; gate power dissipation; gates; power dissipation; practical Josephson microprocessor; ripple-carry method; subnanosecond; Arithmetic; Delay effects; Delay estimation; Equivalent circuits; Josephson junctions; Logic design; Logic gates; Microprocessors; Niobium; Power dissipation; Resistors;
Journal_Title :
Solid-State Circuits, IEEE Journal of
