JPH0636442B2 - Storage device - Google Patents

Description

The present invention relates to a storage device, and more particularly to a storage device that constitutes a digital storage device.

<< Prior Art >> As a memory element that is widely used, for example,
Binary information is stored in the annular magnetic core made of ferrite in correspondence with the direction of the residual magnetic flux, and is detected by using electromagnetic induction. Core memory, information is stored by the amount of charge accumulated in the IC pattern. There are an IC memory for storing information by a flip-flop circuit and a magnetic valve memory for using a bubble generated in a wafer of a thin magnetic storage medium as a storage medium.

Then, these various storage elements have been developed and researched for numerical calculation processing used in connection with the transmission of a computer. As a result, the development purpose is to increase the speed and to correspond to the use of numerical calculation processing.
It was intended to achieve high integration.

<< Problems to be Solved by the Invention >> As described above, in various conventional memory elements, the purpose is to achieve high speed, etc., and although the object is being achieved, various elements have It has a common drawback that it is small and is particularly vulnerable to external electromagnetic noise. This drawback has not been a big problem in terms of malfunction because the conventional memory element is used in a relatively light noise environment called a computer, but it is still a special problem for blocking external magnetic fields. There was a problem such as requiring a large computer room.

In recent years, the use of storage devices (elements) has been expanded with the computerization of various devices, and even in the factory where various noises are generated, especially in the vicinity of devices that generate (use) large power and high voltage. In some cases, an element is used, and in such a case, a disadvantage that it is weak against external noise appears remarkably and cannot be put to practical use. Further, in order to prevent this, the periphery of the storage element can be shielded, but still it cannot be used sufficiently stably.

And in particular, among the above-mentioned memory elements, an IC memory,
The magnetic valve memory is more susceptible to noise, which is even more so. On the other hand, among the various conventional memory elements, the core memory, which is relatively resistant to noise, may be used in the presence of noise by performing the above-mentioned shielding, but in the case of this core memory, each time information is read In order to destroy the stored data, operations such as reading are performed under complicated storage timing, and the storage timing may be erroneous due to the influence of external noise.In such a case, accurate data cannot be read, This causes a problem that stable driving cannot be achieved.

The present invention has been made in view of the above-mentioned various problems, and an object thereof is to be strong against external noises, the use place of the element is not limited, and a device that generates a large power / high voltage, etc. (EN) Provided is a memory device which can be used in the vicinity of the memory device and can be driven stably without causing malfunction.

<< Means for Solving the Problems >> In order to achieve the above-mentioned object, in a storage device according to the present invention, a magnetoresistive effect pattern, a magnetic field generating coil that surrounds the magnetoresistive effect pattern, and a magnetic field generating coil are provided. The coil is provided with driver means capable of passing a current of a predetermined direction and a predetermined magnitude.

Also, a plurality of magnetoresistive effect patterns are arranged on the substrate,
A magnetic field generating coil may be arranged around each of the magnetoresistive effect patterns, and driver means capable of independently supplying an arbitrary current to each magnetic field generating coil may be arranged.

<Operation> When a magnetic field in a predetermined direction is applied to the magnetoresistive effect pattern, its resistance value increases or decreases. Therefore, the magnetic field generating coil provided around the magnetoresistive effect pattern is energized to generate a magnetic field in a predetermined direction to change (for example, increase) the resistance value of the MR pattern. This allows information to be written.

On the other hand, erasing the written information (inputting other data) can be easily performed by supplying an alternating attenuation current to the magnetic field generating coil.

That is, when the direction of the magnetic field is alternately changed by 180 °, the resistance value of the pattern repeatedly increases and decreases. Then, the strength of the magnetic field generated by passing the increased / decreased current gradually weakens, and the resistance value in the non-excited state decreases. Therefore, it finally becomes "small" and the data is erased.

The data can be erased by applying a magnetic field in the direction opposite to that at the time of writing the information "1" and turning off the magnetic field at a proper timing.

<Example> Hereinafter, a preferred example of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows an embodiment of the present invention.

As shown in the drawing, a plurality of narrow strip-shaped magnetoresistive effect patterns (hereinafter, referred to as MR patterns) 2 are formed on the upper surface of a flat plate-shaped substrate 1 which is formed of ceramic or glass or the like and has a substantially rectangular plane. In this embodiment, 5 pieces are arranged in parallel. Then, the magnetic field generating coil 3 is wound around the sides of the substrate 1 in the longitudinal direction so as to cover the MR patterns 2. Then, in the state where each magnetic field generating coil 3 is wound, the magnetic field generating coils 3 are arranged concentrically, and the radial direction of each magnetic field generating coil 3 and the direction of each MR pattern 2 are substantially on the same line. Is done. Further, these magnetic field generating coils 3 are connected to a driver device (not shown) so that a predetermined current can be passed through any magnetic field generating coil 3.

Explaining the MR pattern 2 here, as shown in FIG. 2, when a magnetic field is applied in the same direction as the MR pattern 2, the resistance decreases (see FIG. 2A). On the contrary, when a magnetic field is applied in the direction orthogonal to the MR pattern 2, the resistance increases (see (B) and (C) in the figure). Further, even if the magnetic field is cut once after the magnetic field is applied in a predetermined direction, the residual magnetic flux has a property that the resistance value is maintained at “large” or “small”. Therefore, it can be used as a memory device by changing the direction of the magnetic field facing the binary information and detecting the magnitude of the resistance value of the MR pattern 2 at that time.

Further, the directions orthogonal to the MR pattern 2 are two directions in the two-dimensional direction. Since the resistance value increases in either direction when a magnetic field is applied, there is no problem in using it in either direction when reading and writing information, but the internal spin direction is 180 ° opposite, that is, It is different when looking at the internal structure.

Next, a specific operation of this embodiment will be described. For convenience of explanation, description will be made based on one MR pattern. First, binary information “1” is written in the MR pattern 2 having a small resistance value (corresponding to binary information “0”). First, the driver device (not shown) energizes the magnetic field generating coil 3.
Then, the magnetic field generating coil 3 generates a magnetic field in a direction orthogonal to the MR pattern 2, and this magnetic field causes the pattern 2
Resistance value increases (→ in FIG. 3). Even if the magnetic field is turned off and the magnetic field is not excited, the resistance value is maintained only slightly as shown by → in FIG. As a result, the memory can be retained even after the power is turned off, and it becomes a non-volatile positive memory element.

Next, a case where “0” is stored (rewritten) from this state will be described. In this case, an alternating damping current can be applied to the magnetic field generating coil 3. That is, as shown in FIG. 4, M when the current having a slightly lower peak value in the opposite direction to that when the information “1” is written is applied for half a cycle.
Considering the influence on the R pattern 2, since the direction of the current is reversed, the magnetic field generated from the magnetic field generating coil 3 is also MR.
Although it is orthogonal to the pattern 2, the direction is opposite to the magnetic field when "1" is written. Then, although this direction is also a method of increasing the resistance value, the spin in the MR pattern 2 is reversed as described above.

Therefore, MR when a reverse current is applied for half a cycle
As shown in FIG. 4 (B), the change in the resistance value of the pattern 2 is such that the initial resistance value decreases and becomes “0” once (→
), When it rises again and the instantaneous value of the current reaches the peak value ((a) in the figure), the resistance value of the MR pattern also becomes maximum (→). After that, when the current gradually decreases and becomes a non-excitation state, that is, the current is maintained at a value slightly smaller than the resistance value when the information "1" was written in the previous step. (→).

Thereafter, by applying an alternating damping current as shown in FIG. 5 (A) to the magnetic field generating coil 3, the magnetic field generated from the magnetic field generating coil 3 changes its direction alternately by 180 ° and its strength gradually increases. To decrease. Then, the resistance value of the MR pattern 2 also gradually increases and decreases, and the resistance value in the non-excited state gradually decreases as shown in FIG. Therefore, finally, the resistance value becomes "small", and binary information "0" can be stored (erased).

In this way, by performing the above-mentioned rewriting operation of "1" and "0" to an arbitrary magnetic field generating coil, desired information can be stored in a predetermined MR pattern.

On the other hand, in order to read the information stored in the MR pattern 2, for example, tester means may be connected to both ends of the MR pattern 2 and directly detected (FIG. 6 (A)). Also, MR
A constant voltage V is applied to the pattern 2 and the current flowing in the circuit is measured ((B) in the figure), or the fixed resistor R and the MR pattern 2 are connected in series, and the voltage between the terminals of the MR pattern 2 at that time is It can be performed by various means such as indirectly measuring and detecting by measuring.

It should be noted that, as described above, the reason why the alternating damping current is applied is because the operability is taken into consideration. For example, if the current is cut off when the position shown in FIG. You can also do it. That is, for example, the resistance value (instantaneous value) may be managed and the magnetic field generating coil 3 may be deenergized at a timely timing.

Further, in the above-described embodiment, the radial direction of each magnetic field generating coil 3 and the MR pattern 2 are arranged so as to substantially coincide with each other, but the present invention is not limited to that shown in that embodiment, and for example, both may be used. The directions orthogonal to each other, that is, the MR pattern 2 and the magnetic field generating coil 3 may be positioned concentrically.

<< Effects of the Invention >> As described above, the storage device according to the present invention is a storage element having a new structure that has never existed in the related art, and one of the data is stored by applying a current in one direction to the magnetic field generating coil. Data can be written, and the other data can be written (erased) with simple operability such as passing an alternating decay current or an appropriate current in the opposite direction. In the present invention, one magnetic field generating coil is used for each MR pattern.
Data of progress information can be written (written and erased).

Therefore, higher information, smaller size and cost reduction can be achieved.

Further, since the resistance value of the MR pattern can be checked to detect the storage state, the storage data is not destroyed by reading the data unlike the conventional core memory. Therefore, by sampling a plurality of times when reading data, correct stored data can be surely read even if electromagnetic noise or the like is mixed from the outside at the time of reading.

Further, since it is necessary to apply a relatively large magnetic field in order to rewrite the stored information, there is no risk that the data will be erroneously rewritten at the time of storing and holding the electromagnetic noise generated near the installation location.

[Brief description of drawings]

FIG. 1 is a plan view showing a preferred embodiment of the present invention, FIG. 2 is a view showing characteristics of an MR pattern, FIG. 3 is a graph showing a relation between a magnetic field and an output voltage, FIG. 4, FIG. Is a diagram showing an erasing action on an MR pattern, and FIG. 6 is a diagram showing an example of a method of reading stored information. 1 ... Substrate, 2 ... MR pattern 3 ... Magnetic field generating coil

Claims (4)

[Claims] 1. A magnetoresistive effect pattern, a magnetic field generating coil that covers the periphery of the magnetoresistive effect pattern, and driver means capable of supplying a current of a predetermined direction and a predetermined magnitude to the magnetic field generating coil. A storage device comprising: 2. A plurality of magnetoresistive effect patterns are provided on a substrate, magnetic field generating coils are respectively provided around the respective magnetoresistive effect patterns, and the magnetic field generating coils are independently provided. A storage device provided with driver means capable of supplying an arbitrary current. 3. When one of the binary information is stored in the magnetoresistive effect pattern by the driver means, a current in one direction is passed through the magnetic field generating coil, and when the other information is stored, the coil is alternating. The storage device according to claim 1, wherein an attenuation current is supplied. 4. When the driver means stores one piece of binary information in the magnetoresistive effect pattern, a current in one direction is passed through the magnetic field generating coil, and when the other piece of information is stored, it is stored in the coil. 3. The storage device according to claim 1, wherein a predetermined small current flows in the opposite direction to the one-direction current.