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Non-destructive Readout Memory Element

IP.com Disclosure Number: IPCOM000096960D
Original Publication Date: 1962-Feb-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 40K

Publishing Venue

IBM

Related People

Booth, RR: AUTHOR

Abstract

The core 10 is used in a high speed memory which features non-destructive readout.

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Non-destructive Readout Memory Element

The core 10 is used in a high speed memory which features non-destructive readout.

The current, passing through the CLEAR winding through hole 16, places the core substantially at -BR on the hysteresis loop. When storing a 1, the WRITE pulse reverses the state of saturation of each of the four legs and moves the core from -BR to +BR. To read out the 1 so stored, a READ pulse is applied so that some of domains around hole 16 are switched. The net flux is reduced or slides to point G of hysteresis loop. The READ pulse is sufficiently wide to switch all the reversible and irreversible domains. It attempts to create a net flux distribution around hole 17 in a counterclockwise direction and around hole 15 in a clockwise direction. This is achieved by switching the direction of flux in legs 11 and 13, since direction of flux in legs 12 and 14 is already in the proper direction as seen by the READ pulse. Upon removal of the READ pulse, the net flux around hole 16 relaxes to point H on the hysteresis loop. This is due to the switching of the reversible domains. Successive READ pulses cause the core to shift back to point G as a result of the switching of these reversible domains to achieve nondestructive readout. The SENSE winding then detects a negative flux change -Phi.

Relative to storing and reading of a 0, following CLEAR and INHIBIT pulses cause the core to shift from point -BR to point K of hysteresis loop. The switching of b...