JPS6215950B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control method for a major-minor magnetic bubble memory device having a boot loop.

Recently, devices using magnetic bubbles that use magnetic bubbles to store information, perform logical operations, etc. are nonvolatile, have high storage density, have low power consumption, and are solid-state devices that do not contain any mechanical elements. It has extremely high reliability. The element configuration of such a magnetic bubble memory includes a serial loop system in which the bubble propagation path 1 is an endless loop as shown in FIG. 1, and a major-minor loop system having a major line 2 and a minor loop 3 as shown in FIG. There is a method. As a large-capacity memory, a major-minor loop is advantageous because it can be accessed quickly. However, due to the manufacturing process of the crystal substrate of the magnetic bubble memory, defects in the crystal lattice and defects occurring in the propagation path cannot be avoided. Therefore, in the major minor loop method, a certain number of bad loops are allowed from the beginning, and these bad loops are not used. Information about this defective loop is stored in a specific page of each minor loop, and after reading this information, necessary information is read or written. However, in the reading method of the major minor loop method, as shown in FIG. When the page is read out, the bubbles of the next page are transferred to the major line, and read out in this manner one after another. If reading is performed in this manner, reading may take a long time depending on where on the minor loop the page storing the defective loop information is located.
As a countermeasure against this problem, a boot loop 6 is provided as a special loop for storing defective loop information as shown in FIG. 3, and this loop can be written and read serially. However, writing and reading are normally performed every two bits.
Therefore, if the number of bits in the boot loop is odd,
No matter where the beginning position of the defective loop information is, it can be read by going through the boot loop at least twice. Further, when the number of bits in the boot loop is even, reading becomes impossible if the leading position of the defective loop information is stopped at an odd number of bits away from the transfer gate for reading. Therefore, there is a need to develop a reading method that allows reading even if the number of bits in the boot loop is even, and that allows reading once the beginning of the defective loop information has gone around the boot loop in order to shorten the reading time. has been done. The present invention was devised based on this requirement.

Therefore, in the magnetic bubble memory device control method of the present invention, in a magnetic bubble memory device that has a major-minor loop configuration with one boot loop for storing defective loop information and writes and reads every 2 bits, The starting position of the bad loop information stored in the boot loop is
The rotation of the bubble drive magnetic field is controlled so that when the number of bits in the boot loop is odd, it is stopped at the odd numbered bit from the read replicator, and when the number of boot loop bits is even, it is stopped at the even numbered bit from the read replicator. It is also characterized by the fact that

The system of the present invention will be explained in detail below based on the accompanying drawings.

FIG. 3 shows a magnetic bubble memory device with a boot loop, and reference numeral 6 in the figure shows the boot loop,
7 _-1 to _{7 -o} are minor loops, 8 is a major line for reading, 9 is a major line for writing, 10 is a bubble generator, 11 is a detector, 12 is a replicator for reading the boot loop, 13
is a replicator for reading the minor loop,
14 is a swap gate for writing to the boot loop, and 15 is a swap gate for writing to the minor loop.

FIG. 4 shows a circuit for implementing the method of the present invention in a bubble memory device configured as described above. To explain the figure, the bubble memory device 16 is driven by coil drivers 18, 18' and a function driver 19 controlled by a controller 17 to perform writing and reading. The sense amplifier 20 is used to amplify read data. Here, the drive control circuit 2 according to the present invention
1 is connected to or incorporated into the controller 17 and functions to control the driving magnetic field.

Next, control of a boot loop with an odd number of bits will be explained with reference to FIG. Assuming that the beginning of the defective loop information stops at a position that is an even number of bits ahead of the read replicator (part A) in boot loop 6 as shown in Figure 5a, this beginning position is the bubble propagation indicated by the arrow. Since the number of bits up to replicator A is even when counting in the direction, when reading every two bits, the bits pass through the replicator in the first round and are read out in the second round. In order to eliminate the inconvenience that this readout is performed for the second time, the present invention controls the drive magnetic field so that the leading position of the defective information always stops at a position that is an odd number of bits ahead of the replicator A, as shown in FIG. 5b. By doing this, the beginning of the defective loop information will be an even number of bits up to the replicator A, counting in the bubble propagation direction indicated by the arrow, so that it will always be read within one round.

Next, control of a boot loop with an even number of bits will be explained with reference to FIG. In this case the 6th
If the beginning of the defective loop information stops at a position that is an odd number of bits ahead of replicator A, as shown in Figure a, the distance from that position to replicator A in the direction of bubble propagation indicated by the arrow will be an odd number of bits, no matter how many times it goes around. It is impossible to read. Therefore, in the present invention, the beginning of the defective loop information is always stopped at an even numbered bit from the replicator A. By doing this, the beginning of the defective information is an even number of bits counted in the bubble propagation direction indicated by the arrow, so that it is always read within one round. Note that if two boot loops are used as shown in Figure 6b, and the loop defective loop information is stored in each loop 6 _-1 and 6 _-2 with a shift of 1 bit, it will always be possible to read it within one round, but this In this case, control of the driving magnetic field becomes complicated, which is not preferable.

As explained above, when a boot loop is used, the control method for the magnetic bubble memory device of the present invention reads defective loop information by controlling the drive magnetic field depending on whether the boot loop has an odd or even bit number. This made it possible to do it quickly.

[Brief explanation of the drawing]

Figure 1 is a configuration diagram of an example of a serial loop type magnetic bubble memory, Figure 2 is a configuration diagram of an example of a major-minor type magnetic bubble memory, and Figure 3 is a configuration diagram of an example of a magnetic bubble memory with a boot loop. FIG. 4 is a block diagram of a circuit used in the control method of the magnetic bubble memory device of the present invention, and FIG. 5 is a block diagram of one example.
The figure is an explanatory diagram for explaining control when the boot loop is an odd number of bits, and FIG. 6 is an explanatory diagram for explaining the control when the boot loop is an even number. 6...Boot loop, 7 _-1 to 7 _-o ...Minor loop, 8...Major line for reading, 9...
Major line for writing, 10... Bubble generator, 11... Detector, 12, 13... Replicator, 14, 15... Swap gate, 16... Bubble memory device, 17... Controller, 1
8, 18'...Coil driver, 19...Function driver, 20...Sense amplifier, 21
...Drive control circuit.

Claims (1)

[Claims] 1 In a magnetic bubble memory device that has a major-minor loop configuration with one boot loop that stores defective loop information and writes and reads every 2 bits, the start position of the defective loop information stored in the boot loop is The rotation of the bubble drive magnetic field is controlled so that when the number of bits in the loop is odd, it is stopped at the odd numbered bit from the read replicator, and when the number of boot loop bits is even, it is stopped at the even numbered bit from the read replicator. A control method for a magnetic bubble memory device characterized by: