Browse Prior Art Database

Double Ended Memory Sensing

IP.com Disclosure Number: IPCOM000091571D
Original Publication Date: 1968-Mar-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 36K

Publishing Venue

IBM

Related People

Koehler, HF: AUTHOR

Abstract

This memory is of the type in which ferrite cores, represented by core 2, are arrayed on a set of row and column wires 3 and 4. X and Y drivers are connected to wires 2 and 4 to provide half-select currents for accessing the cores. A balanced pair of sense windings 5 and 6 is wound through the cores of the plane to receive signals that are produced by one core during a read operation. Windings 5 and 6 are terminated at either end by resistors having the characteristic impedance of such winding.

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 100% of the total text.

Page 1 of 2

Double Ended Memory Sensing

This memory is of the type in which ferrite cores, represented by core 2, are arrayed on a set of row and column wires 3 and 4. X and Y drivers are connected to wires 2 and 4 to provide half-select currents for accessing the cores. A balanced pair of sense windings 5 and 6 is wound through the cores of the plane to receive signals that are produced by one core during a read operation. Windings 5 and 6 are terminated at either end by resistors having the characteristic impedance of such winding.

The terminating resistors prevent reflections on windings 5 and 6 and thus reduce electrical noise which can interfere with signal detection. However, the terminating resistors also act as voltage dividers to reduce the portion of the core signal that appears at the end of the line where signals are sensed. For example, the signal voltage produced by core 2 appears on winding 5 and is divided by resistors 7 and 8. The voltage across either resistor is only one half the voltage produced by core 2.

Differential amplifiers 9 and 10 are connected at the opposite ends of windings 5 and 6. The outputs of amplifiers 9 and 10 are combined and applied to detector circuit 11. The signal from core 2 appears in one polarity at the upper terminal of amplifier 9 and in the opposite polarity at the lower terminal of amplifier 10. The two amplifiers provide an enhanced signal to detector 11.

1

Page 2 of 2

2

[This page contains 3 pictures or other non-text objec...