MEMORY DEVICE

Japanese Patent JP2774243

B2

PURPOSE: To improve the performance and reliability by a method wherein, in accordance with the state A or B of an input datum, a magnetic field in a direction corresponding to A or B is applied to an MR device for writing and the written data are read by applying a bias magnetic field whose intensity is lower than the intensity of the magnetic, field for writing.
CONSTITUTION: When the sate A of an input datum for instance '1' is stored, a writing current I is made to flow in the direction of an arrow in Fig. (A) and a magnetic field H which is approximately equal to a magnetic field by which the magnetization of an MR device 6 is saturated is applied to the MR device 6. If the current I is cut off, the datum '1' is stored by residual magnetism. When the state B, i.e., '0', is stored, a writing current-I whose direction is shown in Fig. (B) is made to flow and a magnetic field-H whose intensity is the same as the magnetic field H and whose direction is opposite to that of the magnetic field H is applied to the MR device 6. If the current-I is cut off, the datum '0' is stored by residual magnetism. In order to read the stored datum, a bias magnetic field whose intensity is lower than the intensity of the writing magnetic field (H or -H) is applied to the device 6. It is decided in accordance with the magnitude of the MR ratio of the device 6 at that time whether the stored datum is '1' or '0' and the datum is read out. With this constitution, a memory device which is nonvolatile, can be under a room temperature can be obtained.

Fairness
Kikuchi Hideyuki

JP11556494A

July 09, 1998

May 27, 1994

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富士通株式会社

G11C11/14; G11C11/16; H01L43/08; G11C5/04; (IPC1-7): G11C11/14; H01L43/08

JP330181A
JP2143980A
JP1199390A
JP1198085A
JP5144783B1

Matsumoto

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