JPS5927031B2 - magnetic bubble storage device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic bubble storage device, and more particularly to a magnetic bubble storage device having a major-minor configuration.

BACKGROUND OF THE INVENTION Supported by the remarkable development of electronic technology including semiconductor integrated circuit technology, electronic computers are rapidly becoming smaller and faster.

Furthermore, the reliability has been significantly improved by making the circuit elements solid-state.

Furthermore, as the use of electronic computers progresses, the storage capacity of storage devices continues to increase year by year, and there is a strong demand for lower unit costs and shorter access times for storage.
In order to reliably store and retain large amounts of information, a highly reliable non-volatile large-capacity memory device is required, but this is impossible to achieve with volatile semiconductor memory.
Furthermore, although non-volatile, magnetic tape devices and magnetic disk devices have a fatal flaw in that they have moving parts, and it is difficult to say that these are memory devices that meet needs in terms of reliability.

Magnetic bubbles were invented in view of the above technical background.

When a bias magnetic field of an appropriate magnitude is applied perpendicularly to a magnetic thin plate such as garnet or orthoferrite having uniaxial magnetic anisotropy, a cylindrical magnetic domain, a so-called magnetic bubble, is generated.

A magnetic bubble utilization device that uses these magnetic bubbles to store information, perform logical operations, etc. must be non-volatile, be an all-solid-state element, have a large capacity, and be relatively fast. For these reasons, its practical application is rapidly progressing in fields that take advantage of these characteristics.

This magnetic bubble utilization device requires various functions such as generating, transferring, dividing, enlarging, detecting, and erasing magnetic bubbles.

Furthermore, there is also a bias magnetic field applying means for making the magnetic bubbles stably exist within the magnetic conductive plate, and a rotating magnetic field for moving the magnetic bubbles within the magnetic conductive plate to the base of the magnetic material pattern formed on the magnetic conductive plate. Requires application means. FIG. 1 shows a typical configuration example of a magnetic bubble chip used in a magnetic bubble utilization device.

The illustrated configuration is a so-called major and minor loop configuration, and in the figure, 1 is a major loop, 2 is a minor loop, 3 is a detector, 4 is a light emitter, 5 is a replicator, 6 is an annihilator, 7 respectively indicate transfer gates.

In the figure, the solid line represents a magnetic bubble transfer path formed by a permalloy pattern formed on a magnetic conductive plate, and the broken line represents a conductive pattern made of gold or the like formed on a thin plate.

The operation is performed as follows.

First, in accordance with the information to be written, a current is supplied within the loop of the conductive pattern constituting the generator 4 in a direction that effectively weakens the bias magnetic field to generate a magnetic bubble within the loop.

The generated magnetic bubble is transferred over the major loop 1 by the driving magnetic field rotating in the in-plane direction of the magnetic thin plate, and one piece of information (for example, one piece of information) is transferred to the opposing position of each minor loop 2.
words) are sorted. At this time, transfer gate 7
A current is supplied to the conductor pattern constituting the magnetic bubble group on the major loop 1 into each minor loop 2. The magnetic bubbles sent into each minor loop 2 begin to circulate within the minor loop 2 due to the driving magnetic field, and storage of information is completed. Next, information is read out when the magnetic bubble group in each minor loop 2 to be read reaches a position facing the transfer gate 7, and the conductor pattern is energized to transfer the information onto the major loop 1. The magnetic bubble array transferred onto the major loop is sequentially transferred by the driving magnetic field and reaches the replicator 5VC. The replicator 5 divides the incoming magnetic bubble into two, sends one bubble along the permalloy pattern to the detector 3, and the other via the major loop 1 to the minor loop again. The detector 3 magnifies the magnetic bubbles that arrive one after another in order to increase the detection efficiency, and reads out, for example, a change in magnetoresistance of the magnetoresistive element due to the arrival of the bubbles as a change in voltage. If you want to erase the information and write new information after reading, the divided magnetic bubbles are erased by the annihilator 6 on the major loop and the new information is written to the generator 4. Write by. FIG. 2 shows a magnetic bubble storage device that is an improvement on the embodiment shown in FIG.

This embodiment is a magnetic bubble storage device that is easier to rewrite and has a shorter access time than the embodiment shown in FIG.

In the figure, 11 is a major transfer path, 12 is a minor loop, 13 is a detector, 14 is a generator, 15 is a replicate/transfer gate, 16 is an eraser, and 17 is a circuit that supplies current to the gate 15 and also controls the gate 15. A conductor pattern 18 constitutes a part of the transfer gate, 19 a conductor pattern that supplies current to the transfer gate and constitutes a part of the transfer gate 18, and 20 a guardrail.

Gate 15 in the figure is generally referred to as a replicate/transfer gate, and an enlarged view thereof is shown in FIG. 3a.

In addition, an enlarged view of the transfer gate 18 in the figure is shown in Figure 3b.
Shown below.

The operation is performed as follows.

First, a write operation is performed by the generator 1 according to the information to be written.
Electricity is applied in a direction that effectively weakens the bias magnetic field within the loop of the conductive pattern constituting the conductor pattern 4, thereby generating a bubble within the loop.

The generated bubbles are sequentially transferred onto the first major transfer path 111 by a driving magnetic field rotating in the in-plane direction of the magnetic thin plate, and are aligned by one piece of information at opposing positions of each minor loop 12. Here, the conductor pattern 19 is energized to operate the transfer gate 18, and the major transfer path 11
The bubble group on -1 is sent into each minor loop 12. The magnetic bubbles sent into each minor loop 12 begin to circulate within the minor loop 12 due to the driving magnetic field, and storage of information is completed. The information is read out when the bubble group in each minor loop 12 to be read reaches a position opposite to the gate 15 located on the opposite side to the transfer gate 18 side. The pattern 17 is energized, each bubble is divided into two, and one bubble is returned to the minor loop 12 side, while the other bubble is transferred onto the second major transfer path 11-2.

The bubble train transferred onto the second medium transfer path 11-2 is sequentially transferred by the driving magnetic field and reaches the detector 13. Similar to the embodiment shown in FIG. 1, the detector 13 magnifies the bubbles that arrive one after another and reads out, for example, a change in magnetoresistance of a magnetoresistive element as a change in voltage. The bubble after being read is eraser 1
6 and disappears.

As shown in FIG. 3a, the gate 15 is composed of, for example, a permalloy pattern called a half-disk pattern and a conductor pattern made of gold or the like. All numbers in the figure correspond to those in FIG. 2. Note that the gate shown in X is already publicly known, and a detailed explanation of its operation will be omitted here.
P. if necessary. I. BOny'HardandJ. L
．． Smith: 1976MMM-1ntermagJ0
See intC0nf11A-3 (1976).

Also, when rewriting information, first write each minor loop 12
When the bubble group held at the above address to be rewritten arrives at the gate 15, the conductor pattern 17 is energized with a phase and timing different from that during the division operation, and each gate 1
5 to function, and the bubble group is transferred to the second major transfer path 11-
Transfer on 2.

At this time, the gate 15 does not perform a replicate operation, but performs a transfer operation. Second major transfer path 11-
The bubble group, which is the old information transferred onto 2, is sent to the eraser 16 via the detector 13 and is sequentially erased.

Of course, instead of using the eraser, it is also possible to directly send out the bubble group that is no longer needed to a guardrail (not shown). On the other hand, the vacant addresses of each minor loop from which the bubble group has been removed are sequentially moved by the rotating magnetic field and transferred to the position corresponding to the transfer gate 18.

At this point, current is supplied to the conductor pattern 19 to cause the transfer gate 18 to function. At this time, another new group of bubbles to be written is lined up on the first major transfer path 11-1, and by energizing the conductor pattern 19, the first major bubble is written at the vacant address on each minor loop. New information on one transfer path 11-1 enters, and the rewriting operation is completed.

An embodiment in which the transfer gate 18 is constructed using a half disk pattern is shown in FIG. 3b.

This type of gate was already known before this application, and its operation will be omitted. Now, according to this embodiment, the average access time is shorter than the embodiment shown in FIG.

In other words, the bubble stored in the minor loop 12 can reach the medium-transfer path 11-2 connected to the detector via the gate 15 after going half way around the minor loop 12, so the written information is Reading can be performed in a shorter time than in the configuration shown in FIG. 1, which requires at least one minor loop. However, the first
The configuration shown in FIGS. 2 and 2 requires at least two conductor patterns. Furthermore, since there are a large number of conductor patterns, it is difficult to align them with the magnetic patterns, resulting in a low yield. Furthermore, control of the drive timing of these conductor patterns, etc., cannot help but become complicated.

Furthermore, these embodiments are extremely vulnerable to unexpected power failures such as power outages. In other words, when rewriting information,
Old information is always erased before new information is written, and new information is written after that, but if a power failure occurs during this time, the information content to be erased and the address to be erased, that is, to be rewritten, are monitored. Since the contents of peripheral circuits such as counters are lost, the control order for sending new information to vacant addresses cannot be maintained normally. Incidentally, as a countermeasure against power outage, a converter as shown in FIG. 3c has already been announced and is well known. That is, by arranging the exchanger shown in FIG. 3c in the position of the transfer gate 18 of the embodiment shown in FIG. 2, the above-mentioned problem, that is, the problem of managing the exchange timing of old information and new information, can be solved to a certain extent. I can do it. However, even with the exchanger placed, the conductor pattern still does not decrease.

The present invention has been made in view of the above-mentioned drawbacks, and its object is to realize a magnetic bubble storage device with a small number of conductor patterns.

Another object of the present invention is to obtain a magnetic bubble storage device that requires fewer terminals. Another object of the present invention is to obtain a magnetic bubble memory device having a pattern structure in which pattern alignment is easy during manufacturing and, therefore, yield is high.

Still another object of the present invention is to realize a magnetic bubble storage device that is easy to control and does not require erasing operations when rewriting information. Still another object of the present invention is to realize a magnetic bubble storage device that has an extremely low probability of malfunction even in the event of a power outage such as a power outage.

The object of the present invention is to provide one medium transfer path having a magnetic bubble generator and a magnetic bubble detector, and a plurality of medium transfer paths each having one end connected to the medium transfer path for holding and accumulating magnetic bubbles. In a magnetic bubble storage device having one major and one minor loop, the magnetic bubble is divided by forming a single hairpin-shaped conductor pattern in a connection area between the major transfer path and the minor loop. An exchange circuit is provided, and an exchange operation pulse consisting of a long flat pulse over one cycle of the driving magnetic field and a division operation pulse consisting of a step-like short pulse are energized to write, read, and rewrite the magnetic bubble. This can be achieved by providing a magnetic bubble storage device characterized in that the magnetic bubble division and exchange circuit performs the following.

The present invention will be explained below using the drawings.

FIG. 4 shows an embodiment of a magnetic bubble storage device according to the present invention.

In the figure, 31 is a major transfer path, 32 is a minor loop, 33 is a detector, 34 is a generator, 35 is a division exchange circuit, and 36 is a conductor pattern.

As can be seen from the figure, the transfer control conductor pattern of this example is as follows:
It is composed only of a division switching circuit 35 placed between the minor loop 32 and the major transfer path 31. Split exchange circuit 3
FIG. 5 shows an enlarged pattern configuration diagram of No. 5.

All figures are numbered to correspond to those in Figure 4.
Further, HR indicates a driving magnetic field, and the illustrated embodiment shows the case of triangular wave driving. FIGS. 6a to 6e are diagrams for explaining particularly the switching operation of this divisional switching circuit.

As shown in FIG. 6a, when the drive magnetic field HR is 120, current begins to flow through the conductive pattern 36.

At this time, the bubbles 1a to 1d in the major transfer path 31 are in the positions as shown in the figure, while the bubbles 2a to 2d in the minor loop 2 are in the positions as shown in the figure. The bubbles to be exchanged are 1c and 2c shown with diagonal lines.

Next, when the driving magnetic field HR rotates to the 00 position shown in FIG. Move toward pattern 62.

At this time, the major transfer path 31 and the minor loop 32
The other bubbles 1b, 1c, 1d, 2b, and 2d move within their respective transfer paths or (1) loops, and are located at positions as shown in the figure. Next, the driving magnetic field HR is 1 as shown in Fig. 6c.
When it rotates to 200 degrees, the bubble 1 in the medium transfer path 31
c is moved to the position of the permalloy pattern 61 by the current in the conductor pattern 36 in the same manner as described above, and the bubble 2c from the minor loop 32 is transferred into the major transfer path 31 instead.

At this time, the other bubbles 1b, 1d, 2b, and 2d are in positions as shown in the figure. At this point, the current in the conductor pattern 36 is cut off, and although not shown, the drive magnetic field HR is set to 00.
When rotated to the position, bubble 1c becomes minor loop 32
transferred within.

Through this series of operations, the bubble 1c in the major transfer path 31 and the bubble 2c in the minor loop 32 are exchanged, and the bubble 1c is transferred to the minor loop 32 by the bubble 2c.
is transferred to the major transfer path 31.

At this time, the bubbles 1c, which are exchanged as shown in the figure,
2c are each transferred to their original bit positions.

That is, the bubble 1c is transferred to the bit position where the bubble 2c was located, and the bubble 2c is transferred to the bit position where the bubble 1c was located.

This can be easily understood by comparing the relationship between the front and rear bubbles between FIG. 6a before the exchange and FIG. 6c after the exchange. The above conversion operation will be explained using the time chart shown in FIG.

Figure a shows the driving magnetic field HR waveform, and the current waveform is a triangular wave.

In addition, FIG. 3B shows the waveform and timing of the current supplied to the conductor pattern 36 forming a part of the split exchange circuit 35 during the exchange operation, and FIG. FIG. 3 is a diagram showing the waveform and timing of a current supplied to the device. In the replacement operation, as is clear from the explanation of FIG. 6 and FIG. 6, the drive magnetic field HR is supplied at 1200, and the supply is stopped at 120 of the next cycle.

In the case shown in FIG. 5, the current supply direction is a direction that effectively strengthens the bias magnetic field within the hairpin-shaped region. Also, although the division operation is not shown, as can be seen from figure c, the driving magnetic field HR
When the drive magnetic field HR reaches 200, it starts supplying a current with the same direction and value as during the replacement operation, and when the drive magnetic field HR reaches a value of 220, it starts supplying a current in the same direction and with approximately twice the current value as during the replacement operation for a predetermined period of time. do.

Thereafter, the same current value as when the current supply was started is continued again for a predetermined period of time, and the current supply is stopped when the drive magnetic field HR reaches approximately 00. By supplying such a current to the conductor pattern 36, the bubble stretched out by the driving magnetic field HR on the minor loop is split, and one of the split bubbles is directly sent into the X minor loop 32, while the other bubbles can be sent into the medium transfer path 31 via the permalloy pattern 62 shown in FIG.

In this way, the major transfer path 31 and each minor loop 32
By arranging the division exchange circuit 36 between them, it becomes possible to write, read, and rewrite information using a single conductor pattern.

That is, writing and rewriting of information is performed by operating the above-mentioned division exchange circuit in a switching operation, and reading information is carried out by operating the above-mentioned division exchange circuit in division operation.
In the above-mentioned embodiment, the minor loop 32 is folded back, but this allows the conductor pattern width to be sufficiently widened by ensuring a sufficient area for forming the split switching circuit without reducing the storage density. This type of configuration was adopted to ensure the following, and the present invention does not necessarily require this type of configuration.

As explained above, according to the present invention, it is possible to realize a magnetic bubble storage device that has a small number of conductor patterns, and therefore a small number of terminals, and also allows for easy pattern alignment in manufacturing, and can be expected to improve yield. I can do it.

Further, according to the present invention, it is possible to realize a magnetic bubble storage device that is easy to control, such as eliminating the need for erasing operations, and has sufficient reliability guaranteed even against unexpected power failures such as power outages.

[Brief explanation of drawings]

Fig. 1 shows an example of a conventional magnetic bubble storage device, Fig. 2 shows an example of a magnetic bubble storage device improved from Fig. 1, Fig. 3 shows a conventional gate configuration, and Fig. 4 shows an example of a conventional magnetic bubble storage device. One embodiment of the magnetic bubble storage device according to the present invention, FIG. 5 is an embodiment of the split switching circuit applied to the present invention, and FIGS. 6 and 7 show the operation of the split switching circuit of FIG. 5. It is an explanatory diagram. In the figure, 31 is a major transfer path, 32 is a minor loop, 33 is a detector, 34 is a generator, and 35 is a division switching circuit.

Claims (1)

[Claims] 1. A major transfer path including a magnetic bubble generator and a magnetic bubble detector, and a plurality of minor loops each having one end connected to the major transfer path and holding and accumulating magnetic bubbles. In a magnetic bubble storage device with a major/minor configuration, a magnetic bubble splitting and switching circuit formed with a single hairpin-shaped conductor pattern is provided in the connection area of the major transfer path and the minor loop, and the conductor pattern is driven. An exchange operation pulse consisting of a flat long pulse over one period of the magnetic field and a division operation pulse consisting of a stepped short pulse are energized to write, read, and rewrite the magnetic bubble in the magnetic bubble division exchange circuit. A magnetic bubble storage device characterized by: