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On Chip Column Selection in Bubble Lattice Devices

IP.com Disclosure Number: IPCOM000088519D
Original Publication Date: 1977-Jun-01
Included in the Prior Art Database: 2005-Mar-04
Document File: 2 page(s) / 38K

Publishing Venue

IBM

Related People

Calhoun, BA: AUTHOR [+2]

Abstract

A column-accessed bubble lattice organization is shown schematically in Fig. 1. To access a column of bubbles the lattice is translated left or right until the column to be accessed is positioned within one of the access channels. The column is then read out by translating the column of bubbles along the access channel. A large number of access channels is desirable to reduce the buffer area required and also the amount of lattice translation, and hence the time required to position the desired column in an access channel. One factor which limits the number of access channels is the number of conductor connections.

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On Chip Column Selection in Bubble Lattice Devices

A column-accessed bubble lattice organization is shown schematically in Fig. 1. To access a column of bubbles the lattice is translated left or right until the column to be accessed is positioned within one of the access channels. The column is then read out by translating the column of bubbles along the access channel. A large number of access channels is desirable to reduce the buffer area required and also the amount of lattice translation, and hence the time required to position the desired column in an access channel. One factor which limits the number of access channels is the number of conductor connections. Typically, each access channel requires eight conductor connections: two for the translation of bubbles within the access channel, two for the translation of isolated bubbles in the read and write areas, two for the generation of "one" and "zero" type bubbles, and two for detection of bubbles by a magnetoresistive sensor. The required number of conductors can be drastically reduced by an "on-chip" column selection design.

The write regions are organized as shown in Fig. 2. All bubble generators are connected in parallel so that a bubble of the desired type ("zero" or "one") is generated in every channel. On-chip decoding is used to annihilate the bubbles in all but one of the channels. If conductor A is pulsed when the bubbles are at position a, bubbles in parts 1, 2, 3 and 4 will be annihilated. If conductor A is pulsed when the bubbles are at position a'...