JPH0283865A - magnetic disk device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic disk drive equipped with a multiple write function for protecting important data from data destruction due to abnormal operations.

[Prior Art] In recent years, magnetic disk drives have been developed using S, which is a peripheral device interface for small computers, in order to improve added value and reduce overall system costs.
CS I (Small Computer 5ys
Tea Interface, ) is available.

In this type of magnetic disk device, basic data, such as BAD information (data indicating defective locations on the data recording surface of the magnetic disk) and various parameters indicating drive specifications, are generally used to set the format of the device. It is written every time you do . Furthermore, when a new bad sector occurs, it is necessary to rewrite the BAD information, so each of the parameters described above is rewritten. And one tiger, since these parameters are important data.

It is now written not only in one track, but also in multiple tracks. In this way, important and fundamental data is protected from data corruption due to abnormal operations.

Conventional multiple write processing will be explained below.

For example, there are three magnetic disks with data recording areas on both sides, and one vertical disk facing each side of these magnetic disks.
In a magnetic disk device configured with six magnetic heads arranged in a row, the outermost trunk (0th track) of each of the six data recording areas is used as a set (6 tracks). The 0th cylinder is configured. Then, data of the same content is multiple-written in the 0th cylinder by each magnetic head. At this time, whether or not multiple writing of data has been successfully performed is confirmed by the following processing procedure.

FIG. 6 shows a conventional multiple write confirmation processing routine (hereinafter referred to as confirmation processing routine) performed by a central processing unit (hereinafter referred to as CPLI).

First, in step SPI, the CPU instructs the first magnetic head to read data in the 0th cylinder. Here, the first magnetic head can be any one of the six magnetic heads. The same applies to the second, third, . . . magnetic heads.

In step SPI, the first magnetic node that receives the data read command reads data from a corresponding track among the six tracks constituting the 0th cylinder.

Next, in step SP2, the CPU determines whether the data has been read normally by the first magnetic head. If it is determined that the data has been read normally, the confirmation processing routine ends. On the other hand, in step SP2,
If it is determined that the data has not been read normally, step SP
3, increments the head count by 1, and instructs the second magnetic node to read the data in the 0th cylinder. Upon receiving the read command, the second magnetic head reads data in the corresponding track.

After that, the CPU again performs the second
It is determined whether or not data is successfully output one after another by the magnetic head. At this time, if it is determined to be rYESJ, the confirmation processing routine ends, but if it is determined to be "NO", the process proceeds to step SP3, the head count is incremented by 1, and the third magnetic head is Commands reading in the 0th cylinder. Thereafter, the above processing procedure is repeated.

In this way, if data is normally read out from even one of the six multiplex-written tracks, the confirmation process ends.

[Problems to be Solved by the Invention] By the way, due to the occurrence of an unexpected situation, the data written in the 6 tracks in the 0th cylinder, which should originally be the same, may become inconsistent. For example, if an instantaneous NR interruption occurs during writing by the third magnetic head, the recorded contents of the three tracks written by the first to third magnetic heads and the remaining three tracks will be changed from now on. It will remain as it is. In this situation, 0
When data is destroyed due to an abnormal operation on one of the tracks of the cylinder, the next time data is read from another track of the 0 cylinder, different or incorrect data may be read. .

For this reason, the reliability of the device and data could not be said to be sufficient.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a magnetic disk device that prevents the occurrence of mismatch between multiple written data and improves reliability.

[Means for Solving the Problems] The present invention has a plurality of magnetic heads for writing and reading data, and each of the magnetic heads writes the same data multiple times in a preset cylinder. In the disk device, whether or not a number data addition means for adding write number data indicating the number of times of multiple writing to the data matches all of the write number data in the data read by each of the magnetic heads. and when it is determined that there is a discrepancy by the determining means,
The above problem is solved by providing a rewrite control means that performs multiple writing again using the latest data.

[Operation] The multiple written data includes write count data. If a mismatch occurs in the write count data read by each magnetic head, data including the latest write count data is automatically written multiplexed again.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

FIGS. 1 and 2 schematically show the configuration of a magnetic disk device that is an embodiment of the present invention.

In these figures, reference numeral 1 denotes a case, and the bottom of this case l serves as a base la.

A spindle motor 2 is fixed to the base 1a, and the spindle of the spindle motor 2 has three magnetic disks DK, . . . , DK, 4DK, . . . from the top in the figure.

is fixed via a spacer. magnetic disk dk
. Similarly, magnetic disk DK3.
．． Both sides are data recording surfaces D3. D4, magnetic disk D
Both sides of Ks and e have data recording surfaces D5 and D6. Also, magnetic disk DK.

DK5. , ,DK, , are adapted to rotate in the direction of arrow A as the spindle motor 2 rotates. I]1 is a magnetic head for writing and reading data to and from the data recording surface D1, and is arranged opposite to the data recording surface D1. Similarly, magnetic heads 82 to H6 write and read data to and from the data recording surfaces D2 to D6, respectively, and are arranged opposite to the data recording surfaces D2 to D6, respectively.

In addition, since these magnetic nodes H1 to H6 are arranged in a single vertical line, any of the six tracks can be accessed at will by simply switching the magnetic nodes H1 to H6. One cylinder is composed of six tracks gathered together.

The magnetic nodes H1 to H6 are magnetic disks D K ++
,.

Due to the rotation of D K s,a, D K s,s, the air flow generated on these surfaces causes a minute amount (0,2
They are each supported by spring-like hemlock arms AI-A6 so that they can levitate (0μ to 0.40μ). The head arm AI-A6 is fixed to the carrier 3. This carrier 3 is rotatable in the 13-B direction about the pivot 4 as a rotation axis. 5 is a linear motor that can obtain a driving force proportional to the current, and the carrier 3 is connected to B-
Since it is directly coupled and driven in the B direction, it can run on the base la.

Further, FIG. 3 is a block diagram showing the configuration of a data reproducing circuit related to the magnetic disk device having the above configuration (FIGS. 1 and 2). In the figure, numeral 6 is a first data amplifier that amplifies data read out by the magnetic node H1, and 7 is a second data amplifier.
8 is a data amplifier, 8 is a filter circuit, 9 is a data pulse generator circuit that pulse encodes data and outputs it, IO is an AGC that controls the gain of the second amplifier 7 and keeps its output constant.
It is an amplifier (automatic gain control circuit). Similarly, the magnetic nodes H2 to H6 are also connected to a data reproducing circuit having the same configuration as that in FIG. FIG. 4 is a block diagram showing the configuration of a microcomputer that controls multiple writing. In the figure, reference numeral 10 is a CPU that controls each part of the device, 11 is a RAM in which various data are temporarily stored, 12 is a ROM in which a program that gives commands to the CPU10 is stored, and 13 is an output from the data pulse generation circuit 9. Data CPU10
This is an interface that can be imported into the . 14 is CPU
l0 and RAMII, ROM12, interface 13
It is a path line that connects the

Next, the operation of the magnetic disk device having the above configuration will be explained.

To perform multiple writing of the predetermined data rDATA in the 0th cylinder, if the number of multiple writes corresponds to the Nth time, the CPU l0 writes the predetermined data rDATA.
Data rNJ indicating the number of times of writing is added to AJ, and writing is performed to the magnetic node H1. Next, magnetic head H2
Write the same way as above. Similarly, below,
Writing is performed sequentially by the magnetic heads H3 to H6. In the manner described above, multiple writing of data is completed.

Next, CPtJlo confirms the multiple written data as described above according to the confirmation processing procedure shown in FIG.

CPLIIO first, in step S Pal,
The magnetic head H1 is commanded to read data in the 0th cylinder. The magnetic node H1 that received this command
reads data from the 0th track on the data recording surface DI. Thereafter, the same read operation is sequentially performed on all the magnetic heads H2, H3, . . . H6. Next, the CPU10 proceeds to step 5Pa2, compares the data rNJ included in the six data read by all the magnetic nodes H1 to H6, and compares the six data rNJ.
Determine whether all of J match. If it is determined that they match, the confirmation processing routine ends.

On the other hand, in step 5Pa2, six data rNJ
If it is determined that there is a discrepancy in even one of them (
In this case, at least one of the data rN-IJ is read instead of the data rNJ. ), CPUl0 is
Moving to step 5Pa3, to the magnetic node H1-Ha,
Latest data 1N.

Write DATAJ again using the same procedure as described above. In this way, all magnetic nodes 1-1l-86
After rewriting is performed, the confirmation processing routine ends.

In the above embodiment, a case has been described in which all the data IN and DATAJ written multiplexed are read, but instead of this, only the data rNJ indicating the number of times may be read.

Further, in the above embodiment, the confirmation processing routine is ended after the latest data is written again in step 5Pa3, but the present invention is not limited to this. After that, the confirmation processing routine may be executed again from step 5Pal.

Furthermore, in the above-described embodiment, a case has been described in which reading and rewriting by each magnetic head is performed sequentially from the highest magnetic head downward, but the order is not limited to this. (The magnetic head may be moved upward sequentially from the lowest position, or any other order may be set.

[Effects of the Invention] As explained above, according to the magnetic disk device of the present invention, when a mismatch occurs in the data multiplexed by each magnetic head, the data is automatically replaced with the mismatched data. , the latest data is multiplex-written again.

Therefore, the reliability of the device and data can be further improved.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing a schematic configuration of a magnetic disk device according to an embodiment of the present invention, FIG. 2 is a sectional view showing the internal structure of the same embodiment, and FIG. FIG. 4 is a block diagram showing the configuration of the data reproducing circuit, and FIG. 5 is a block diagram showing the configuration of the microcomputer.
FIG. 6 is a flowchart showing the same multiple write confirmation processing routine, and +2- FIG. 6 is a flowchart showing the conventional multiple write confirmation processing routine. Hl-Ha...Magnetic head, 10...
CPU (number of times data addition means, judgment means, rewrite control means).

Claims (1)

[Scope of Claims] A magnetic disk device having a plurality of magnetic heads for writing and reading data, and in which each of the magnetic heads writes the same data multiple times to a preset cylinder, comprising: a number data adding means for adding write number data indicating the number of times of writing to the data; and a determining means for determining whether all of the write number data in the data read by each of the magnetic heads match. and rewrite control means for performing multiple writing again using the latest data when the determination means determines that there is a discrepancy.