Browse Prior Art Database

Cylindrical Domain Shift Register with Reduced Latency

IP.com Disclosure Number: IPCOM000075805D
Original Publication Date: 1971-Nov-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 53K

Publishing Venue

IBM

Related People

Lin, YS: AUTHOR [+2]

Abstract

In serial memory organization where data is written or read serially, extra delay in accessing time results if the stored information has to be recirculated within the memory. For instance, the stored information may not be in the proper sequence for readout, requiring additional time to shift data to the proper sensing point before readout can occur. In a cylindrical magnetic domain memory, the latency problem can be overcome by interrupting the in-plane rotating field or by reversing the field sequence of the rotating field during alternate cycles in order to move the bubble back and forth, thereby holding it in its position. However, interruption of the in-plane field results in delay due to the response time of the driving coil.

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 61% of the total text.

Page 1 of 2

Cylindrical Domain Shift Register with Reduced Latency

In serial memory organization where data is written or read serially, extra delay in accessing time results if the stored information has to be recirculated within the memory. For instance, the stored information may not be in the proper sequence for readout, requiring additional time to shift data to the proper sensing point before readout can occur. In a cylindrical magnetic domain memory, the latency problem can be overcome by interrupting the in-plane rotating field or by reversing the field sequence of the rotating field during alternate cycles in order to move the bubble back and forth, thereby holding it in its position. However, interruption of the in-plane field results in delay due to the response time of the driving coil. Reversal of the field sequence limits the operating frequency, because the inertia force of the domain tends to slow the speed of response.

Cylindrical domain cells using a local feedback loop at each bit location, eliminates latency time without changing the applied inplane field. This feedback loop is implemented using a permalloy disk circuit or a permalloy T-bar circuit, having both magnetically hard and magnetically soft materials.

In Fig. 1A, a top view of a permalloy disk apparatus is shown in which the disks 10 in solid lines are located on the top of the magnetic sheet 12, while the disks 14 shown in dashed lines are located on the bottom side of the magnetic sheet. Magne...