A Josephson 4 bit RALU for a prototype computer

Author

Nakagawa, Hiroshi ; Kosaka, Shin ; Kawamura, Hiroki ; Kurosawa, Itaru ; Aoyagi, Masahiro ; Hamazaki, Youichi ; Okada, Yoshikuni ; Takada, Susumu

Author_Institution

Electrotech. Lab., Ibaraki, Japan

Volume

24

Issue

4

fYear

1989

fDate

8/1/1989 12:00:00 AM

Firstpage

1076

Lastpage

1084

Abstract

A Josephson 4 bit register/arithmetic logic unit (RALU) which is adaptable to a prototype computer is discussed. The RALU circuit is designed to be composed of ALU, accumulator, registers for 10 bit instructions, 8 bit address, 4 bit data and carry flag, multiplexers, and so on. It consists of a four-junction logic (4JL) gate family of OR, AND, INVERT, and AMP gates. A complete set of photomasks of the RALU has been generated with the computer-aided-design system which performs an automatic standard cell layout, wiring, and logic check. The RALU chip has been fabricated using a 3 μm Nb/AlO_x/Nb tunnel junction technology. Sixteen power voltage regulator junctions and 1273 logic gates are integrated on the 4.3×5 mm² chip. Operations have been confirmed for all 24 kinds of instructions in the RALU chip. Total power dissipation is 1.66 mW. A delay time of 300 ps has been evaluated for generating the SKIP signal to control the program address in the sequence control unit, which is essential to achieve one instruction execution for every high-speed clock cycle

Keywords

aluminium compounds; cellular arrays; logic CAD; logic gates; niobium; superconducting logic circuits; 1.66 mW; 3 micron; 300 ps; AMP gates; AND gates; Nb-AlO_xNb; OR gates; RALU; SKIP signal; accumulator; carry flag; computer-aided-design system; four-junction logic; high-speed clock cycle; instruction execution; inverters; multiplexers; photomasks; power dissipation; power voltage regulator junctions; prototype computer; register/arithmetic logic unit; registers; sequence control unit; standard cell layout; Circuits; Digital arithmetic; Josephson junctions; Logic gates; Multiplexing; Niobium; Prototypes; Pulse inverters; Registers; Wiring;

fLanguage

English

Journal_Title

Solid-State Circuits, IEEE Journal of

Publisher

ieee

ISSN

0018-9200

Type

jour

DOI

10.1109/4.34095

Filename

34095