JPS6330718B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for driving a magnetic bubble memory device in which detection of magnetic bubbles is synchronized with transfer bubbles.

The circuit configuration of magnetic bubble memory uses the major/minor loop method, and magnetic bubbles (hereinafter referred to as bubbles) are used.
An odd-even configuration (hereinafter referred to as "odd-even") is often used, which processes information at high speed by dividing it into odd number sequences and corner number sequences.

FIG. 1 is a block diagram of a device having an odd-even configuration. By adopting such a configuration, the writing and reading speed of bubble information is increased.

In other words, the bubble information is divided into an odd number sequence (Odd) and a corner number sequence (Even), and each of these is processed in the device by an odd number block that handles the bubble information of the odd number sequence and a corner number block that handles the corner number sequence. Each block has a bubble generator and detector.

Now, in Fig. 1, if the blocks on the left are odd-numbered blocks and the blocks on the right are corner-numbered blocks, then the bubble signals of the same configuration, in which the electric signals are converted into bubble signals in generators 1 and 2, are generated on the major lines 3 and 4 of the respective blocks. are propagated and aligned at write positions 7 and 8 opposite to the minor loop groups 5 and 6 of each block.

Here, the number of bits in the transfer path constituting the major lines 3 and 4 is made so that the odd number block and the corner number block are different by one bit, and each minor loop group 5 and 6 is made at every other bit of each major line 3 and 4. Therefore, when the odd numbered columns of bubble information are lined up at opposing positions 7 of each minor loop group 5 of an odd numbered block, the corner numbered columns of bubble information are lined up at opposing positions 8 of each minor loop 6 of the corner numbered blocks. By the action of the transfer gate 9, the bubble signals on the write major lines 3 and 4 are transferred to the write positions 10 and 11 of the opposing minor loops,
The driving magnetic field circulates within the minor loops 5 and 6.

Next, as for the reading method, when the bubble information to be read is transferred to the reading positions 14 and 15 of the minor loop group facing the reading major lines 12 and 13, it is transferred to the major lines 12 and 13 by the action of the transfer gate 16, and thereafter by the driving magnetic field. The signals are transferred along the measure lines 12 and 13 and detected by the detectors 17 and 18.

Here, even in the readout major lines 12 and 13, the number of constituent bits is made to differ by 1 bit between the odd-numbered block and the corner-numbered block, so the bubble information of the odd-numbered block and the bubble information of the corner-numbered block are detected alternately, and the result is It appears as the original electrical signal.

The present invention relates to synchronization of a stretching current and a driving magnetic field for bubble detection in a bubble memory device detector having such an odd-even configuration.

That is, bubble information consisting of odd number columns is transferred to the readout major line 12 in FIG. 1, and bubble information consisting of corner columns is transferred to the readout major line 13 every other bit.

A case will be described below in which the measure line is formed by a continuous transfer pattern formed by ion implantation, and bubble detection is performed by current stretching the bubble and detecting it using a magnetoresistive element.

FIG. 2 shows a state in which a signal consisting of an odd number column or a corner number column is transferred along a readout major line and detected by a detector. In this case, it is assumed that the bubble signal consists of 111 continuous signals.

Here, the bubbles 22 and 23 that are being transferred along the continuous transfer pattern 21 in accordance with the rotation of the driving magnetic field shown in FIG. 3 are located one bit apart from each other in the transfer pattern.

Here, the detector consists of a bubble stretcher 24 made of a hairpin-shaped conductor pattern and a magnetoresistive element 25, and the curved part inside the tip of the bubble stretcher 24 has a pattern with the cusp 26 of the connected transfer pattern 21 in the center. A magnetoresistive element 25 is provided in the gap between the conductive patterns constituting the bubble stretcher 24, with the conductive intersections insulated with a silicon oxide (SiO ₂ ) layer or the like.

Note that a region 27 surrounded by parallel broken lines is a non-ion implanted region formed similarly to the connected transfer pattern 21.

Here, the method for detecting and erasing bubbles is to transfer the bubble to the bubble stretcher 24 in a direction in which the bias magnetic field inside the hairpin weakens when the bubble is transferred and reaches the cusp position 26 of the connected transfer pattern 21 where the bubble stretcher 24 is located. When a pulse current is applied, the bubble 22 at the cusp position 26 is stretched to the inner surface of the bubble stretcher 24, and the magnetic field from the stretched bubble changes the resistance value of the magnetoresistive element 25, which performs detection. Erasing is performed by applying a pulse current to the stretcher 24 in the opposite direction.

Now, the bubble is transferred by following the rotation of the driving magnetic field from about 135° to 225° as shown in Figure 3, and from about 225° to 225°.
The 270° movement range from 135° remains at the cusp position, and bubble detection and elimination must be performed during this period.

Detection and erasure performed during one rotation of this driving magnetic field poses no problem if the driving frequency is low, but becomes more difficult as the driving frequency increases.

For example, in Figure 2, the effective length of the magnetoresistive element is
If the bubble is 100 μm and the bubble expansion speed Vs is 60 m/sec, it takes 1.7 μsec just for the bubble to expand to 100 μm.

Here, when the driving frequency is 100 KHz, the time the bubble stays at the cusp position of the continuous transfer pattern is 7.5 μs, but when it is 300 KHz, it is shortened to 2.5 μs, and during this time, the bubble is expanded, detected, and It is difficult to perform erasure.

As a solution to this problem, the inventors focused on the fact that in the odd-even configuration, the bubble signals transferred along the concatenated transfer pattern are arranged every other bubble signal, and the bubble signals are transmitted at a rate of once every 2 bits of transfer. proposed a detection method in which a pulsed current is applied to a stretch conductor.

In this method, bubble expansion, detection, and erasure can be performed alternately in two transfer cycles, so that it is possible to cope with an increase in the driving frequency.

However, when bubble detection is performed every two bits of transfer in this way, it is necessary to synchronize the application of pulse current to the bubble stretcher and bubble transfer.

The purpose of the present invention is to synchronize the two, and as a method for this purpose, the bubble memory device is started or stopped so that the bubble exists at a position several corner bits away from the detected bit position.

The present invention will be explained below with reference to the drawings.

In a bubble memory device having an Odd-EVen configuration, bubbles transferred along the concatenated transfer pattern 21 are always present at every other position.

On the other hand, the repetition period of the pulse current flowing through the bubble stretcher 24 for expanding and erasing the bubble is once every two transfer periods. If the bubble signal array consists of 111 continuous signals, a necessary condition for bubble detection is that a pulse current be applied to the bubble stretcher 24 when the signal bubbles are at positions 22 and 23 in FIG. If the signal bubbles are at positions 28 and 29, and the bubble stretcher 24 is energized in this case, no bubbles will be detected, and when the next bubble stretcher is energized, the bubbles at positions 28 and 29 will be 30. and 28, and no detection is performed at all.

As a method to prevent such malfunctions, the present invention, when starting or stopping a memory device, always stops the device when the bubble arrives at a position several corner bits away from the detection bit position of the concatenated transfer pattern. The main idea is to synchronize the drive and the pulse current energization of the bubble stretcher.

In this embodiment, a case has been described in which detection is performed once every two transfer cycles, but the present invention can be similarly implemented in a method in which detection is performed once every two or more cycles.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram of a bubble memory device with an odd-even configuration, Figure 2 is an explanatory diagram of the operation of a magnetic bubble detector provided in a connected transfer pattern, and Figure 3 is a diagram of the rotating magnetic field method and bubble It is a relationship diagram with transfer. In the figure, 21 is a concatenated transfer pattern, 24
is a bubble stretcher, 25 is a magnetoresistive element, 2
6 is cusp position, 22, 23, 28, 29, 30
is a magnetic bubble.

Claims (1)

[Claims] 1 It has an odd-even configuration, and the detector consists of a bubble stretcher and a magnetoresistive element, and detects and erases magnetic bubbles transferred along the continuous transfer pattern formed by ion implantation every two bubble transfer cycles. In the magnetic bubble memory device to be used, the magnetic bubbles detected by the detector stop at a position several corner bits away from the detection bit position where the detector is located on the transfer pattern, and the magnetic bubble is driven. A method for driving a magnetic bubble memory device characterized by synchronizing detection with and.