Browse Prior Art Database

Nonvolatile NDRO Array Logic Memory Cell in Josephson Technology

IP.com Disclosure Number: IPCOM000081880D
Original Publication Date: 1974-Aug-01
Included in the Prior Art Database: 2005-Feb-28
Document File: 2 page(s) / 29K

Publishing Venue

IBM

Related People

Terlep, KD: AUTHOR

Abstract

The figure shows a "read-mostly" superconducting memory cell for array logic use. Basic cell definition is described adjacent to the figure. Cell operation and characteristics are described below: Cell Personalization Write "1" (Clockwise Circulating Current approx. Io/2) 1) Apply currents Io and Iw to switch Josephson device Jw. 2) Remove current Iw. 3) Remove current Io. Write "0" (Eliminate Circulating Current) 1) Apply current Iw of magnitude sufficient to switch device Jw with Io/2 circulating current.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 58% of the total text.

Page 1 of 2

Nonvolatile NDRO Array Logic Memory Cell in Josephson Technology

The figure shows a "read-mostly" superconducting memory cell for array logic use. Basic cell definition is described adjacent to the figure. Cell operation and characteristics are described below: Cell Personalization Write "1" (Clockwise Circulating Current approx. Io/2) 1) Apply currents Io and Iw to switch Josephson device Jw. 2) Remove current Iw. 3) Remove current Io. Write "0" (Eliminate Circulating Current) 1) Apply current Iw of magnitude sufficient to switch device Jw with Io/2 circulating current.

In practice all cells in a row would be reset to 0 and those cells requiring 1's would then be written. Use With Array Logic

Array logic's potential for electronically implementing engineering changes should prove to be very important for Josephson technology used in a large- scale integrated (LSI) environment. Speed of operation should be high, due to the transmission line system used and the large fanout characteristics of the technology.

The described cell provides a high-density approach which implements the following logical function between data and cell personality:

(Image Omitted)

Referring to the figure, the cell output is described by device Js switching "1" if a 1 has been previously stored and if data is a 1 (To). Thus device Js switches for total control current Io but not for Io/2. Total control current for device Js is the superposition of stored circulating current and data curren...