JPS63873B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Technical Field of the Invention The present invention relates to a magnetic bubble memory element used as a memory for electronic computing devices or terminals thereof.

(2) Technology background Magnetic bubble memory is nonvolatile, has high storage density,
It has various characteristics such as low power consumption and extremely high reliability because it is a solid-state device that does not contain any mechanical elements, so it is expected to have a future as a large-capacity memory. ing.

This magnetic bubble memory element has a large number of fine patterns made of permalloy thin films formed on a single crystal thin film such as orthoferrite or magnetic garnet, which has uniaxial anisotropy and has an easy axis of magnetization only in the C-axis direction of the crystal. Then, by applying a perpendicular bias magnetic field to the single crystal thin film, the cylindrical magnetic domain (called a bubble) that is generated is moved by an external magnetic field, and the presence or absence of bubbles in the permalloy pattern corresponds to information "1" or "0". It is used as a memory. A replicated generator is used as one of the bubble generation mechanisms of such a magnetic bubble memory element.

(3) Prior art and problems Figure 1 shows an example of the configuration of a conventional replicated generator. In the figure, 1 is a pickaxe-shaped permalloy pattern, 2 is a hairpin-shaped conductor, and 3
indicates a loop formed by a half-disk permalloy pattern, 4 indicates a writing line, and 5 indicates a seed bubble.

As shown in the figure, this consists of a 7-bit closed loop including a permalloy pattern 1 and a generate replicate gate consisting of a conductor 2, and a seed bubble 5 is written in each bit. To write data, a replicate pulse is applied to the conductor 2 of the generate replicate gate at a necessary timing to divide the seed bubble 5 and transfer it to the write line 4.

On the other hand, when the bubble transfer path of a bubble memory element has a major-minor configuration, there are usually defective loops in the minor loop group due to defects in crystals, masks, processes, etc. For this reason, the defective loop data is written in advance to a special map loop in the ROM or bubble memory element on the control device side, and processing is performed so that the defective loop is not used during writing and reading. However, this defective loop processing method has the drawback that if the defective loop data on the device side is corrupted for some reason, a bubble will be written into the defective loop by mistake, causing a failure.

(4) Purpose of the Invention In view of the above-mentioned drawbacks of the conventional technology, the present invention writes data directly corresponding to a defective loop in the generator loop of a replicated generator in the form of a seed bubble, and reads out the contents of the generator loop. It is an object of the present invention to provide a highly reliable magnetic bubble memory element that can perform its functions and at the same time prevent access to a defective loop due to an erroneous write signal.

(5) Structure of the Invention According to the present invention, in a magnetic bubble memory element having a major/minor configuration, a plurality of replicators are arranged in a closed loop having a number of bits equal to or greater than the number of minor loops. This is achieved by providing a magnetic bubble memory element that stores address information of a defective loop in the closed loop and has a function of writing bubble information using the replicator.

(6) Examples of the invention Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 2 is a diagram showing a magnetic bubble memory device according to the present invention. In the figure, 10 is a generate/replicate gate, 11 is a seed bubble readout replicator, 12 is a generator loop,
Reference numeral 13 indicates a major line for writing, and reference numeral 14 indicates a major line for reading.

In this embodiment, the number of permalloy patterns 15 constituting the generator loop 12 is equal to or greater than the number of minor loops, and constitutes a closed loop.
Two replicators 10 and 11 are provided within this generator loop 12. One of the replicators 10 is composed of a pickaxe-like permalloy pattern 16 and a hairpin-like conductor pattern 17, and is capable of generating seed bubbles, dividing the seed bubbles, and transferring the bubbles to the writing medium line 13. There is. The other replicator 11 is composed of a pickaxe-like permalloy pattern 18 and a hairpin-like conductor pattern 19, and is capable of dividing the seed bubble and transferring the bubble to the reading measure line 14.
Note that at least two such closed loops are connected to one element.
It is also possible to provide more than one.

The operation of this embodiment configured in this way will be explained using FIG. 3. FIG. 3 is a diagram schematically showing an example of a bubble memory element composed of four minor loops, in which 12 is a generator loop, 13 is a major line for writing, 14 is a major line for reading, D is a detector, G/R is a generate replicate gate, R and R' are replicators, S is a swap gate or transfer gate, No. 1 to No. 4 are minor loops, and black circles represent bubbles.

Now, in the diagram, there are four minor loops No. 1 to No.
It is assumed that No. 3 out of 4 is a defective loop, and that the generator loop 12 is composed of 13 bits. Seed bubbles are written to positions 1, 2, and 4 in the figure using the generate replicate gate G/R, and position 3, which corresponds to the defective loop, is left empty. Data is written to the minor loop by applying a replicate pulse to the generate replicate gate G/R to divide the seed bubble, and the divided bubble passes through the write major line to a predetermined swap or transfer gate position 1'. , 2', 3', and 4' and written in each minor loop. At this time, if a bubble is accessed by mistake to the defective loop No. 3, the bubble will not actually enter the defective loop because there is no seed bubble at bit position 3 corresponding to No. 3. On the other hand, by providing a reading replicator R' in a part of the generator loop 12 and reading out the seed bubbles therefrom, the generator loop 12 can also function as a defective loop. Further, in an actual device, a bit for detecting the start address may be added to the generator loop.

Next, the operation when the present invention is applied to an odd/even block configuration will be explained with reference to FIG. In this figure, the same parts as in FIG. 3 are designated by the same reference numerals. Note that A is an odd block and B is an even block. In this example, there are eight minor loops No. 1 to No.
8, of which No. 3 and No. 6 are defective loops. A seed bubble is placed in each block's generator loop 12, 12' as shown in the figure.
~8 is written continuously, and it is No. 3 of the defective loop.
The bit positions corresponding to No. 6 and No. 6 are left empty. Generate Replicate Gate G/R ₁ ,
The conductor patterns of G/R ₂ are connected in series, and data is written to the element by passing a replicate pulse therethrough. The divided bubbles are transferred to predetermined swap or transfer gate positions 1' to 8' through write medium lines 13 and 13'. At this time, the number of bits of the write major line is shifted by 1 bit in odd and even blocks A and B, so the bubbles are shifted by 1 bit in odd and even blocks as shown in 1' to 8' in the figure, and odd number block A is shifted by 1 bit in odd numbered blocks A and B. Even-numbered bubbles are stored in the even-numbered block B, and the position of the defective loop becomes an empty bit. On the other hand, when reading the address of a defective loop, the contents of the generator loops 12, 12' of odd or even blocks can be read using the replicator R'.

(7) Effects of the Invention As explained above in detail, the magnetic bubble memory element of the present invention uses a closed loop having a number of bits greater than the number of minor loops as a generator loop, and includes bits corresponding to good loops in the closed loop. By writing a seed bubble only to the position and leaving the defective loop position as an empty bit with no seed bubble, even if an incorrect write signal is input and the defective loop is accessed by mistake, the seed bubble will be written at that position. Since there is no bubble, writing of bubbles to defective loops can be prevented and reliability can be improved, which is a great effect.

Furthermore, if another reading replicator is provided in the generator loop, the defective loop address can be read by reading the data of the seed bubble, and it can also be used as a map loop for the defective loop.

[Brief explanation of the drawing]

FIG. 1 is a diagram for explaining a conventional replicated generator, FIG. 2 is a diagram for explaining a magnetic bubble memory device according to the present invention, and FIGS. 3 and 4 are diagrams for explaining a magnetic bubble memory device according to the present invention. FIG. 3 is a diagram for explaining the operation. In the drawing, 10 is a generator/replicate gate, 11 is a replicator, 12 is a generator loop, 13 is a writing medium line,
14 is a reading major line, 15, 16, 1
8 shows a permalloy pattern, and 17 and 19 show conductor patterns, respectively.

Claims (1)

[Claims] 1. In a magnetic bubble memory element having a major/minor configuration, a plurality of replicators are arranged in a closed loop having a number of bits equal to or greater than the number of minor loops, and address information of a defective loop is stored in the closed loop. 1. A magnetic bubble memory element characterized in that the replicator is provided with a bubble information writing function. 2. The magnetic bubble memory device according to claim 1, wherein a bubble magnetic domain is generated in at least one of the replicators. 3. The magnetic bubble memory device according to claim 1, wherein a single chip has at least two or more of the closed loops.