Browse Prior Art Database

Redundancy Sharing Between Islands on a Multi-Island Ram

IP.com Disclosure Number: IPCOM000043858D
Original Publication Date: 1984-Oct-01
Included in the Prior Art Database: 2005-Feb-05
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Fitzgerald, BF: AUTHOR [+4]

Abstract

This article describes the concept of redundancy implementation that allows redundant lines to cross an island or array boundary. More specifically, a redundant line can be "borrowed" from another array, significantly increasing the redundancy flexibility. This design requires: 1. The redundant lines in the array. 2. The appropriate line steering circuitry to connect the redundant line and deactivate the line with bad bits. 3. The address compare circuitry, which is programmed to identify the selection of lines to be replaced. The efficiency of the redundancy increases significantly if two redundant lines are put in each array rather than one, and the steering circuitry is altered such that the lines could be electrically shared between two islands.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 99% of the total text.

Page 1 of 1

Redundancy Sharing Between Islands on a Multi-Island Ram

This article describes the concept of redundancy implementation that allows redundant lines to cross an island or array boundary. More specifically, a redundant line can be "borrowed" from another array, significantly increasing the redundancy flexibility. This design requires: 1. The redundant lines in the array.
2. The appropriate line steering circuitry to connect the redundant line and deactivate the line with bad bits. 3. The address compare circuitry, which is programmed to identify the selection of lines to be replaced. The efficiency of the redundancy increases significantly if two redundant lines are put in each array rather than one, and the steering circuitry is altered such that the lines could be electrically shared between two islands. With this design, the compare circuitry and steering circuitry are shared by one redundant line per associated island, thus allowing both lines to be used in one island and none in the other. The extra line is borrowed from one array, to be used in the other array. This significantly increases the efficiency of the redundancy. The additional circuits required in a design having four arrays, each with two redundant lines, is: 1. Redundant lines
. . . . . . . . . . 8 2. Steering Circuits . . . . . . . . . 4 3. Address compare circuits . .
. . . 4 The additional four redundant lines allow for a second failing bit or line in any array to be replaced, which makes the...