JPS6338798B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in magnetic bubble memory devices. Magnetic bubble memory devices have various features such as being non-volatile, capable of large-capacity, high-density storage, low power consumption, small size and light weight, and are therefore expected to have a promising future as a large-capacity memory. This magnetic bubble memory device utilizes the fact that magnetic bubbles generated in a magnetic thin film such as magnetic garnet can be moved freely by a magnetic field.As shown in FIG. It is composed of rotating magnetic field generating coils 2, 2' for driving, bias magnetic field generating magnets 3, 3' for stably holding the bubble, etc.

The memory element 1 is made by forming a thin film of magnetic garnet by liquid phase epitaxial growth on, for example, a Gatolinium-Gallium-Garnet (GGG) substrate, and forming a bubble propagation path using a fine pattern of a permalloy thin film on top of the thin film of magnetic garnet. Information is recorded as "1" where there is a bubble and "0" where there is no bubble. The configuration of this propagation path can be roughly divided into a serial loop system and a major-minor system, and the latter is used as a large-capacity memory because of its fast access speed.

FIG. 2 shows the element configuration of an example of the major-minor system. To explain the diagram 4
is a bubble generator, 5 is a major line for writing connected to the bubble generator, 6 _-1 to 6 _-o are minor loops for storing information, 7 is a major line for reading, and 8 is a detector connected to the major line for reading. be. and minor loop 6
_-1 to 6 _-o to write line 5 via transfer gate 9 _-1 to _-o , replicate gate 10 _-1
~10 _-o to the readout line 7, respectively.

Such a major-minor type element configuration has the drawback that as the element capacity increases, the number of minor loops and the number of minor loop bits increase, and the average access time becomes longer. On the other hand, if the number of minor loop bits is decreased and the number of minor loops is increased in an attempt to shorten the access time, the shape of the element becomes vertically or horizontally long as shown in Figure 3, which reduces the number of elements that can be taken from the wafer and increases the number of elements during projection exposure. Problems such as a decrease in resolution and difficulty in packaging arise. The present invention was devised to solve these problems.

Therefore, in the present invention, information writing and
In a magnetic bubble memory element with a major/minor configuration that has a major line for reading and a plurality of minor loops for storing information, the minor loops are divided into two groups, a first and a second group, and arranged in parallel. Each group is equipped with a dedicated bubble generator and a detector that is used in common for both groups, the write line of the first group is longer than the write line of the second group, and the read line of the second group is longer than the read line of the first group. The first and second groups are formed longer than the line, and the first and second groups are
The information strings lined up on the write lines of each group are simultaneously transferred to the minor loop, and the information strings transferred onto the read line by the read pulses at the same timing are the last of the information strings replicated from the first group. The tail is followed by the beginning of the information string replicated from the second group, so that it can be read out continuously by the detector.

Embodiments of the present invention will be described in detail below based on the accompanying drawings.

An example is shown in FIG. In this embodiment, the minor loop groups 6 _-1 to 6 _-o of the vertically long elements shown in FIG. Move to the left side and arrange the first and second groups in parallel as shown in Figure 4.
Each group is provided with a bubble generator 4, 4', and one detector 8 is provided which is used commonly by both groups. The length of the writing line 5 from the entrance point f of the last minor loop B of the first group to the bubble generator 4 is from the entrance h point of the last minor loop D of the second group to the bubble generator 4'. The length of the writing line 5' is longer than the length of the writing line 5' of the minor loops C and D at both ends of the second group by the number of bits between the entrances g and h points + P (where P is the number of bits between adjacent minor loops). The length of the readout line 7' from the detector 8 to the exit point c of the minor loop C at the beginning of the second group is longer than the length from the detector 8 to the exit point a of the minor loop A at the beginning of the first group. Minor loop A at both ends of
It is made longer by the number of bits between the exit points a and b of B+P.

In this embodiment configured in this manner, as is clear from FIG. 5, the length of the write line 5 in the first group is longer than that in the second group by the number of bits between the minor loops at both ends of the second group + P. only longer, readout line 7
The length of the second group is longer than that of the first group by the number of bits between the minor loops at both ends of the first group +P, and Fig. 4 can be considered to be the same element as Fig. 5 in appearance. Can be done. Therefore, the present embodiment shown in FIG. 4 can perform the same operation as the conventional device shown in FIG. Moreover, the vertically long shape of the element is eliminated,
It becomes possible to form the shape into a square or a shape close to the square, and it is possible to obtain effects such as an improvement in the element extraction rate from the wafer, an improvement in the resolution during projection exposure, and an improvement in the ease of patterning.

Next, another embodiment is shown in FIG. This embodiment is formed by arranging two loop configurations shown in FIG. 4 in parallel, and numeral 11 is a bubble generator;
12 is a write line, 13 _-1 to 13 _-o are minor loops, 14 is a read line, and 15 is a detector. By setting the number of bits in each part to the relationship shown in the table below, an odd-even type is achieved, making it possible to achieve twice the capacity and twice the data rate with the same access time. In this loop configuration, the positions of the mean lines of the generator and detector of block 1 and 2 differ by 1 bit from those of block .

Table (-)=(-)+1 or -1 (-2')=(3'-4')+1 or-1 (-)=(-)-1 or-1 (5'-)=(7' −) −1 or −1 ( 1′ − 2′ ) − (−) = (−) ( 3′ − 4′ ) − (−) = (−) (−) − ( 5′ −) = ( 9′ − 5′ ) (−) − ( 7′ −) = ( 10′ − 7′ ) For example, in the above table, (→) represents the number of bits from point to point.

As explained above, in the magnetic bubble memory device of the present invention, by dividing the minor loop group into two groups and arranging them in parallel, it is possible to make the device into a square shape or a shape close to the square shape, thereby improving the yield of devices from wafers. This makes it possible to improve the resolution during projection exposure and the ease of packaging.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an example of a magnetic bubble memory device, FIGS. 2 and 3 are block diagrams showing the major-minor configuration of the device, and FIG. 4 is a magnetic bubble memory according to an embodiment of the present invention. Element configuration diagram, 5th
The figure is a diagram explaining the principle, and FIG. 6 is a configuration diagram of another embodiment. 4, 4', 11... Bubble generator, 5, 5', 1
2...Writing line, 6 _-1 ~ 6 _-o , 13 _-1 ~
13 _-o ...minor loop, 7,14...readout line, 8,15...detector.

Claims (1)

[Claims] 1. In a magnetic bubble memory element with a major-minor configuration that has a major line for writing and reading information and a plurality of minor loops for accumulating information, the minor loop groups are divided into two groups, the first and second groups, and are parallelized. Each group is equipped with a dedicated bubble generator and a detector commonly used for both groups, and the write line of the first group is connected to the second
The read lines of the second group are formed longer than the read lines of the first group, and the read lines of the second group are lined up on the respective write lines of the first group and the second group by write pulses at the same timing. The information strings are simultaneously transferred to the minor loop, and the information strings transferred onto the readout line by the read pulses at the same timing are replicated from the second group after the last of the information strings replicated from the first group. 1. A magnetic bubble memory device characterized in that the beginning of an information string continues and can be read out by a detector.