JPS623483A - magnetic bubble device - Google Patents

Abstract

PURPOSE:To shorten widely the time needed for reading and to execute a high speed action by providing plural magnetic bubble detecting means on one magnetic bubble transfer path for reading. CONSTITUTION:At a minor loop 4, an ion implantation system magnetic field driving type transfer path is used, and for a major line 12 for writing and a major line 11 for reading, an electric current driving type transfer path is used. The reading action transfers the necessary magnetic bubble to the upper edge of the loop 4 by the rotating magnetic field at 300kHz. Thereafter, the magnetic bubble at the upper edge is shifted to a line 11, and transferred on the line 11 by a pulse electric current at 1.2MHz. When a head magnetic bubble comes to a detecting device D1, pulse electric current impression is stopped and the transfer of the magnetic bubble is stopped. Next, detecting devices D1-D16 are operated, and the presence and the absence of the magnetic bubble are detected. After the completion of the detection, the magnetic bubble on the line 11 is transferred again, and the next magnetic bubble is transferred to the detecting devices D1-D16. thus, the reading time is shortened and the high speed action can be executed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a magnetic bubble detection means for a magnetic bubble memory device, and more particularly to a magnetic bubble device that makes it possible to detect (read) magnetic bubbles at high speed.

[Background of the invention]

Currently, the magnetoresistive effect of magnetic materials is used exclusively to detect magnetic bubbles, but these magnetic bubble detectors can be roughly divided into two types depending on the film thickness of the magnetic material used.
0-500 A thin film type, 3000-5000
Type A is called thick film type. Typical thin-film and thick-film detectors are shown in FIGS. 4 and 5. Permalloy, which is a Ni-Fe alloy, is generally used as the magnetic material. In order to obtain a practically sufficient output in a detector that utilizes the magnetoresistive effect, a magnetic film with a length of about 100 μm is used for a thin film type, and about 1 yen for a thick film type. Therefore, the magnetic bubble must also be stretched to this length.

FIGS. 4 and 5 are diagrams schematically showing conventional thin film type and thick film type magnetic bubble detectors, respectively. Fourth
In the figure, 1 is a magnetic bubble transfer path using a chevron pattern, 2 is a hairpin-shaped conductor for extending magnetic bubbles, and 3 is a magnetic bubble detector using a thin film magnetic wire 31 and a lead wire 32. A current is applied to locally generate a magnetic field within the region surrounded by the hairpins, and the magnetic bubble between the chevrons of the transfer path 1 is expanded within the region to the length of the detector 3. Detected. In addition, in the case shown in FIG. 5, the magnetic bubble transfer path l using a chevron pattern is arranged so that the number of chevrons is sequentially increased in the direction of the detector 3, and the magnetic bubbles are sequentially expanded to the length of the detector 3. is being detected. The biggest problem with the above-mentioned magnetic bubble detector is its detection speed.

The expansion speed of the magnetic bubble is about 20 m/s.

Therefore, like the detector shown in Figure 1, one magnetic bubble can be
It takes 5 μs to stretch to 00 μm. If we convert this into a frequency, it will only be 200kHz at most.

Currently, it uses a magnetic field drive method, and the practical frequency is 200 k.
This is about Hz and is not a problem, but it will become a big problem in the future if the speed is increased by a current drive method or the like.

Regarding thin film magnetic bubble detectors, please refer to "Magnetic Bubble" edited by Yoshifumi Sakurai (September 30, 1980, published by Ohmsha)
210-213, and a thick film magnetic bubble detector is described in U.S. Pat. No. 3,702,995.

[Purpose of the invention]

An object of the present invention is to provide a magnetic bubble detection means suitable for a magnetic bubble memory device operating at high speed.

[Summary of the invention]

A method for driving magnetic bubbles at high speed in a magnetic bubble memory element is described in The Bell System Technical Journal/l/ (The Be1l System
Technical Journal), Vol. 58, No. 6, p. 1453 (1979).
“Current-Access Magnetic Bubble Circuit 7 (Current-Ac
cess Magnetic Bubble Circu
The current drive method is said to be the most promising.

In addition, an attempt to shorten the access time by using this current drive method only in a part of the magnetic bubble memory element was also proposed by 'IEE Transactions on Magnetics'.
ctions on Magnetics)', No. M
AG-13, No. 5, pp. 1261-1263 (
6 Combinations of Field and Current Access Magnetic Bubble Circuits (COMBINATION OF FIELDA) by E. H. L. Scheputka et al. (1977)
ND CURRENT ACCESS MAGNET
"ICBUBBLE CI RCUI TS)".

However, these documents do not contain any descriptions directly related to the present invention.

The major feature of the current drive method is that it is possible to drive the magnetic bubble at high speed, and at the same time, it is easy to start and stop driving the magnetic bubble, and even change the driving speed.

The present invention focuses on such characteristics of the current drive method, and provides a magnetic bubble memory device that operates at high speed by providing a plurality of magnetic bubble detectors on the read transfer path and operating these detectors simultaneously. This is what I am trying to do.

FIG. 2 is a diagram showing the configuration of a magnetic bubble detection section of a magnetic bubble memory device according to the present invention.

On the reading magnetic bubble transfer path 11, there are N magnetic pull detectors connected in parallel. Assume now that the number of bits of information to be read at one time is nxN. Here, n is preferably an integer, but does not necessarily have to be an integer. The information transferred through the reading magnetic bubble transfer path 11, ie, the array of magnetic bubbles, enters the magnetic bubble detection section. At this time, the interval between the magnetic bubble detectors is adjusted to the interval between the magnetic bubbles. Then, the beginning of the information (
When the address, O) reaches the detector Dr, the Nth information (address, N-1>) reaches the magnetic bubble detector.Here, at least the transfer of the magnetic bubble in the readout transfer path 11 is This can be easily accomplished by stopping the application of the current for magnetic bubble transfer or by increasing the period of the series of pulsed current applications required for magnetic bubble transfer. In this way, enough time is created to detect the magnetic bubble, and during that time the magnetic bubble is detected.When the detection is completed, the magnetic bubble is transferred again at the normal speed,
The transfer continues until the N+1st information (address, N) reaches the detector, and then it is stopped again or the transfer rate is converted. In this way, magnetic bubbles are detected in units of N pieces. FIG. 3 shows the voltage sequence for magnetic bubble transfer and detection as described above. Figure fa) shows a clock for magnetic bubble transfer, and figure b shows the timing of magnetic bubble detection. In this example, the transfer is stopped during magnetic bubble detection. Although not shown in FIG. 3, processing necessary for magnetic bubble detection is performed at the timing of magnetic bubble detection. For example, in the case of a magnetic bubble detector as shown in FIG. 4, a pulse current is applied to the hairpin-shaped conductor 2 for expanding the magnetic bubble, and a voltage change appearing at both ends of the magnetic wire 31 of the detector 3 is detected. 32 is a lead wire.

Since this series of processing usually ends within 10 μs, it is sufficient to stop magnetic bubble transfer in about 10 μs. Moreover, since this detection process is performed simultaneously for all detectors 1 to N and -DN, the hairpin-shaped conductors 2 do not need to be independent from each other (they may be connected in series or in parallel).

[Embodiments of the invention]

The present invention will be explained in detail below using examples.

FIG. 1 shows an example in which the present invention is applied to a magnetic bubble memory element that has a major line/minor loop configuration, and in which only the major line part is current-driven and the minor loop is magnetic field-driven in order to shorten access time. Explain using.

In the figure, the dotted line portion is the minor loop 4, and in this embodiment, an ion implantation type magnetic field driven transfer path is used to increase the recording density. The solid line portions are major lines for writing 12 and reading 11, which are current-driven transfer paths. Major line 11.12 and minor loop 4
Since the transfer methods are different, both can be driven completely independently. That is, the magnetic bubbles on the noja line 11, 12 can be transferred while the magnetic bubbles on the liner loop 4 remain stopped. Moreover, if necessary, the writing major line 12 and the reading major line 11
The readout measure line 11 has 16 detectors as shown in the figure.
~D+6 is the arrangement. Here, a thin film type detector as shown in FIG. 1, which occupies a small area, was used. Transfer within the final loop 4 is performed by a rotating magnetic field generated by a pair of coils installed around the chip, and its frequency is 3.
00kHz. Transfer within the normal line 12 is performed by applying a current directly to a conductor provided on the chip, and its frequency is set to 4 of the minor loop 4.
The frequency was doubled to 1.2 MHz.

The read operation is performed as follows. The required magnetic bubble is transferred to the upper end of the minor loop 4 by a rotating magnetic field (300 kHz). Thereafter, the magnetic bubble at the upper end is transferred to the reading measure line 11, and transferred on the same measure line 11 by a pulse current (1.2 MH
z). When the first magnetic bubble reaches the detector, the pulse current application is stopped and the transfer of the magnetic bubble is stopped.

Next, the detector operates %DI to detect the presence or absence of magnetic bubbles. When the magnetic and -able detection is completed, the magnetic bubbles on the major line are transferred again, and the next 16 bits worth of magnetic bubbles are transferred to the detectors D1 to I)+a. Thereafter, magnetic bubbles on the reading measure line are detected by the same procedure.

Compare the access time with the prior art. The number of minor loops is 512, that is, there are 512 magnetic bubbles on the major line, and there are 512 magnetic bubbles from the first magnetic bubble to the detector.
Suppose there is a bit. Then, to read out the entire magnetic bubble, 512+512=1024 bits must be transferred. Therefore, in the conventional technology, 300kHz
It takes about 5.1 mS to transfer and detect the data. According to the present invention, assuming that transfer is performed at 1.2 MHz and detection is approximately 3.3 μs (300 kHz) as in the prior art, approximately 853 μS is required for transfer and 211 μS is required for detection, resulting in a total of 1.06 m5. , it is 1/3 of the conventional technology.

〔Effect of the invention〕

As explained above, according to the present invention, the detection speed of magnetic bubbles can be substantially increased compared to the conventional technology, the time required for reading can be significantly shortened, and a magnetic bubble memory device that operates at high speed can be realized. It can be realized.

[Brief explanation of drawings]

Figure 4 is a schematic diagram of a conventional thin film magnetic bubble detector.
The figure is a schematic diagram of a conventional thick-film magnetic knob/L and a detector. Figure 3 is an explanatory diagram of a magnetic bubble detection unit according to the present invention. Figure 2 is an explanation of transfer and detection of magnetic bubbles according to the present invention. Figure, 1st
The figure is an explanatory diagram of an embodiment of the present invention. In fig. 1... Magnetic bubble transfer path 2... Hairpin-shaped conductor 3... Magnetic bubble detector 4... Minor loop (ion implantation transfer path) 5...
magnetic bubble generator

Claims (1)

[Scope of Claims] 1. A magnetic bubble device comprising at least a write magnetic bubble transfer path and a read magnetic bubble transfer path and a storage magnetic bubble transfer path connecting both of the magnetic bubble transfer paths, wherein the one read magnetic bubble transfer path A magnetic bubble device comprising a plurality of magnetic bubble detection means on a bubble transfer path. 2. The magnetic bubble device according to claim 1, wherein at least the reading magnetic bubble transfer path near the magnetic bubble detection means is of a current-driven type.