JPH1139102A - Magnetic disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic device capable of accelerating disk access and improving the reliability of the entire device. SOLUTION: The (n) pieces of the heads of respective head parts 1a-1l are disposed corresponding to the (n) pieces of the tracks of respective disk surfaces 2a-2l. A write/read circuit 5 sends out parallel data, sent from a data width conversion circuit 7 through a data modulation/demodulation circuit 6 to the head parts 1a-1l through a selector circuit 3 and sends out the parallel data sent from the head parts 1a-1l through the selector circuit 3 to the data width conversion circuit 7 through the data modulation/demodulation circuit 6. The data width conversion circuit 7 converts the data width of data from a host into the data width corresponding to the number of the (n) pieces of the heads of the respective head parts 1a-1l to be sent out to the data modulation/ demodulation circuit 6 and converts the data width of the data from the data modulation/demodulation circuit 6 to the data width for the host, to be sent out to the host.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a magnetic disk drive, and more particularly to a data access method in a magnetic disk drive.

[0002]

2. Description of the Related Art Conventionally, in a magnetic disk device, a plurality of disk surfaces are provided in the device, and one head is provided for each of those disk surfaces.
In this case, when writing data to the disk surface, the parallel data sent from the host device is converted into serial data, and the data is recorded on the disk surface by a corresponding head.

When reading data from the disk surface, serial data is read from the disk surface using a corresponding head, and the serial data is converted into parallel data before being transferred to a host device.

In the parallel access method, data sent in parallel to each disk surface is described as parallel data. However, when reading / writing data, data is always accessed after seeking. .

In such a magnetic disk device, when accessing data at an arbitrary location on the disk surface, the head is sought to a location where the data is located to access the data. The seek takes an average of 40-60m
s is much longer than the average rotation waiting time (8.3 ms), which accounts for most of the time required for the host device to access the disk surface, and is a bottleneck in improving the data transfer speed.

With respect to the magnetic disk device as described above, the technology disclosed in Japanese Patent Application Laid-Open No. 03-084706 and the technology disclosed in Japanese Patent Application Laid-Open No. 04-061071 have been proposed.

[0007]

In the above-mentioned conventional magnetic disk drive, in the case of the method of accessing the disk surface in the parallel system, the data is always accessed after seeking when reading / writing data. The loss time of the seek time that occurs at the time of data transfer becomes very large.

In the above-mentioned magnetic disk drive, when the parallel data is converted into serial data at the time of writing and written, and when the serial data is converted to parallel data at the time of reading and transferred to the host, the parallel data is converted from the serial data to the data at the time of data transfer. , Or conversion from serial data to parallel data, which is very inefficient.

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic disk drive which can solve the above-mentioned problems, can speed up disk access, and can improve the reliability of the entire apparatus.

[0010]

A magnetic disk drive according to the present invention is a magnetic disk drive comprising a disk surface having a plurality of tracks, wherein the magnetic disk device is provided corresponding to each of the plurality of tracks on the disk surface. The plurality of heads and the data width of data from the host device are changed according to the number of tracks on the disk surface, and then the plurality of heads simultaneously write on the disk surface and the plurality of heads simultaneously write from the disk surface. Means for changing the read data to the data width of the host device and transferring the read data.

In another magnetic disk drive according to the present invention, when performing data transfer between a plurality of disk surfaces each having a plurality of tracks and a host device, one of the plurality of disk surfaces is selected. A plurality of heads arranged corresponding to each of the plurality of tracks on each of the plurality of disk surfaces, and a data width of data from the host device. After changing according to the number of tracks on the surface, the data simultaneously written to the disk surface by the plurality of heads and simultaneously read from the disk surface by the plurality of heads are changed to the data width of the host device and then transferred. Means.

Another magnetic disk drive according to the present invention comprises:
1. A magnetic disk drive comprising a disk surface having a number of tracks (n is a positive integer), comprising: n heads disposed on the disk surface corresponding to each of the n tracks; M bits (m is a positive integer, m
.Ltoreq.n) is changed to n-bit data, and the n-bit data simultaneously written on the disk surface by the n heads and simultaneously read from the disk surface by the n heads is m-bit data. Means for transferring the information to the higher-level device after the change.

Still another magnetic disk drive according to the present invention is a data storage device comprising: a disk device having l (l is a positive integer) tracks each having n (n is a positive integer) data; A selector circuit for selecting one of said l disk surfaces when performing a transfer, wherein said selector circuit is arranged corresponding to each of said n tracks on each of said l disk surfaces. The set n heads and m-bit (m is a positive integer, m ≦ n) data from the higher-level device are changed to n-bit data, and then the n heads are simultaneously applied to the disk surface. Means for changing the n-bit data written and simultaneously read from the disk surface by the n heads to m-bit data, and then transferring the data to the host device.

That is, the magnetic disk drive of the present invention comprises:
On each disk surface having n (n is a positive integer) tracks, n heads are provided corresponding to each of the n tracks. In this magnetic disk drive, at the time of writing to each disk surface, an m-bit width (m
Is a positive integer, m ≦ n), converts parallel data into n-bit width and sends it to n heads. When reading data from each disk surface, n-heads simultaneously read n-bit width data and read n-bit data. The width data is converted into m bits and transferred to the host.

As a result, the write / read time in the magnetic disk drive can be greatly reduced, and high-speed access to data can be realized. Also, by using this method, the seek of the head is eliminated, the access can be performed only by the rotation waiting time, and the precision mechanical parts used conventionally can be deleted, so that the failure rate is reduced and the magnetic disk is reduced. It is possible to improve the reliability of the entire device.

[0016]

Next, an embodiment of the present invention will be described with reference to the drawings. 1A is a sectional view of a disk surface according to an embodiment of the present invention, FIG. 1B is a plan view of the disk surface according to an embodiment of the present invention, and FIG. 2 is an embodiment of the present invention. FIG. 2 is a block diagram illustrating a configuration of a magnetic disk device according to an example.

In these figures, a magnetic disk drive according to an embodiment of the present invention has head units 1a to 1l each having n (n is a positive integer) heads 1a0 to 1an,.
A disk medium 2 having l (1 is a positive integer) disk surfaces 2a to 2l; a selector circuit 3;
, Write / read circuit 5, data modulation / demodulation circuit 6
And a data width conversion circuit 7. Note that l
Each of the disk surfaces 2a to 2l is provided with n tracks in advance.

N heads 1 in each of the head portions 1a to 1l
a0 to 1an,... are arranged corresponding to n tracks on each of the disk surfaces 2a to 2l. The selector circuit 3 selects one of the head sections 1a to 11 according to the switching signal 101 from the write / read circuit 5, and transfers the data (D0 to Dn) from the write / read circuit 5 to the head sections 1a to 1n. 1l is output in parallel to the head 1
The parallel data (D0 to Dn) from a to 11 are sent to the write / read circuit 5. The motor 4 rotationally drives the respective disk surfaces 2a to 2l of the disk medium 2.

The write / read circuit 5 sends the parallel data (D0 to Dn) from the data modulation / demodulation circuit 6 to the selector circuit 3, and outputs the parallel data (D0 to Dn) from the selector circuit 3 to the data modulation / demodulation circuit. Send to 6.

The data modulation / demodulation circuit 6 modulates the parallel data (D0 to Dn) from the data width conversion circuit 7 and sends the modulated data to the write / read circuit 5, and the parallel data (D0 to Dn) from the write / read circuit 5. ) Is demodulated and sent to the data width conversion circuit 7.

The data width conversion circuit 7 outputs a data width [m bits (m is a positive integer, m ≦ m) of data 8 from a host (not shown).
n)] is replaced with n heads 1a0 of each of the head portions 1a to 1l.
The data is converted into a data width corresponding to the number of .about.1an,... And transmitted to the data modulation / demodulation circuit 6. The data width conversion circuit 7 converts the data width of the data from the data modulation / demodulation circuit 6 into the data width of the data 8 from the host, and sends it to the host.

FIG. 3 is a diagram showing a relationship among a head, a track, and a sector in one embodiment of the present invention. These figures 1
The operation of the magnetic disk drive according to one embodiment of the present invention will be described with reference to FIGS.

First, a case where the data width of the host and the data write / read width (the number of tracks) on the disk medium 2 are the same (m = n) will be described. In this case, the data width conversion circuit 7 does not convert the data width.

First, when writing data from the host to the disk medium 2, m-bit parallel data (Dm = Dn) 8 from the host is sent from the data width conversion circuit 7 to the data modulation / demodulation circuit 6 as it is. . The data modulation / demodulation circuit 6 simultaneously modulates the data D0 to Dn sent in parallel at the same time and sends the data D0 to Dn to the write / read circuit 5.

The write / read circuit 5 determines which of the plurality of disk surfaces 2a to 2l is to be recorded on, and
Switching signal 101 and modulated parallel data D0 to D0
n to the selector circuit 3. The selector circuit 3 receives the parallel data D0 to
Dn is sent to each of the heads 1a0 to 1an of the head section 1a corresponding to the recording surface (disk surface 2a).

At this time, the parallel data D0 to Dn are sent in such a relationship that the 0th bit data D0 is sent to the head 1a0 and the nth bit data Dn is sent to the head 1an.
When the sector to be written comes under the heads 1a0 to 1an, the data D0 to Dn are simultaneously recorded on the disk surface 2a.

That is, the data D0 to Dn are as shown in FIG.
As shown in (b), data is written on the same sector of the track corresponding to each of the heads 1a0 to 1an. For example, 1
The fourth to fourth data are written on the same sector of each of the different tracks.

Next, the data to the host is transferred to the disk medium 2.
When data is read from the host, when a data request is input from the host, the write / read circuit 5 outputs a switching signal 101, and the data surface (the disk surface 2) on which data is recorded is output.
Search for a). When the disk surface 2a on which data is written is found, a sector of the data to be read is searched for, and the head 1a0
When the data comes to the heads 1a0-1a
An simultaneously reads data D0 to Dn from the disk surface 2a.

Data D0 read from disk surface 2a
.About.Dn are sent to the write / read circuit 5 through the selector circuit 3 in parallel. The write / read circuit 5 sends the data D0 to Dn read from the disk surface 2a to the data modulation / demodulation circuit 6 in parallel. Data modulation /
The demodulation circuit 6 receives the data D0 read from the disk surface 2a.
.. Dn are simultaneously demodulated in parallel and sent to the host through the data width conversion circuit 7.

Next, the case where the data sent from the host is smaller than the write / read width of the disk surfaces 2a to 2l (m <n) will be described. Here, for the sake of explanation, n
/ 2> m.

First, when writing data from the host to the disk medium 2, when parallel data (Dm <Dn) having a data width of m bits is transmitted from the host, the data width conversion circuit 7 is transmitted first. Latched data and read the next data from the host. The data width conversion circuit 7 sends the read data (the first data and the next data) to the data modulation / demodulation circuit 6 as 2m-bit width data.

The data modulation / demodulation circuit 6 modulates the data whose data width has been converted by the data width conversion circuit 7 and writes / modulates the data.
It is sent to the reading circuit 5. Thereafter, data is written to the disk surfaces 2a to 2l through the same process as described above.

At this time, as shown in FIG. 3, the positional relationship between the data written on the disk surfaces 2a to 2l is such that the first data and the second data are written on the first track, The third data and the fourth data are written to the track No. 5, and the fifth data and the sixth data are further written to the adjacent track. The bit width actually sent is 2m bits, and the 2m bits are n
Since the number of bits is smaller than the number of bits, an invalid data sector is generated in each track.

Next, the data to the host is transferred to the disk medium 2.
When a data request is input from the host, the write / read circuit 5 searches for data from the disk surfaces 2a to 21 and reads the data in n widths in the same manner as in the above process. Disk surface 2 by write / read circuit 5
The data read from a to 2l is demodulated by data modulation / demodulation circuit 6 and sent to data width conversion circuit 7. The data width conversion circuit 7 deletes invalid high-order bit data from the data demodulated by the data modulation / demodulation circuit 6, divides the remaining data into lower-order m bits and upper-order m bits, and sends the resulting data to the host with an m-bit width. .

FIG. 4A is a diagram showing an example of data sent from the host to the magnetic disk device according to one embodiment of the present invention, and FIG. 4B is a diagram showing the data sequence of the disk shown in FIG. It is a figure showing the example of writing on a surface. The specific operation of the embodiment of the present invention will be described with reference to FIG. 1, FIG. 2, and FIG. In FIG. 4, the disk surfaces 2a to 2l
Has 8 (= n) tracks, and 3 bits (=
m) shows an example in which data of a width is sent.

First, when writing data from the host to the disk surface 2a of the disk medium 2, the host sends parallel data (D00, D01, D02, D10, D11,
(D12, D20, D21, D22, D30, D31, D32,...) Are sent, the data width conversion circuit 7 latches the first sent data and reads the next data from the host.

The data width conversion circuit 7 sends the read data (the first data and the next data) to the data modulation / demodulation circuit 6 as 6-bit data. In this case, the data width conversion circuit 7 calculates 2 × data width (= 6) <the number of tracks (= 8)
Since the data width is doubled, there are still two extra bits, so that the first data D00 and the next data D01 have a 2-bit dummy value (=
0) is added and sent to the data modulation / demodulation circuit 6.

As a result, the 3-bit parallel data (D00, D01, D02, D10, D11, D1) from the host can be obtained.
2, D20, D21, D22, D30, D31, D32, ...)
The first data string (D00, D01, D02, D10, D11, D1
2, 0, 0), the second data string (D20, D21, D22, D3)
(0, D31, D32, 0, 0).

The data modulation / demodulation circuit 6 modulates the data whose data width has been converted by the data width conversion circuit 7 and writes / modulates the data.
It is sent to the reading circuit 5. Thereafter, data is written to the disk surface 2a through the same steps as described above. In this case, the head 1a0 outputs D00, D20,... And the head 1a1 outputs D01, D20.
.., The head 1a2 is D02, D22,..., The head 1a3 is D10, D30,.
.., The head 1a5 is D12, D32,..., The head 1a6 is 0,0,.
.. Are simultaneously written to the disk surface 2a, respectively (see FIG. 4B).

Next, the data to the host is transferred to the disk medium 2.
When data is read from the host, when a data request is input from the host, the write / read circuit 5 searches for data from the disk surface 2a and reads the data with an 8-bit width in the same manner as in the above process. Disk surface 2 by write / read circuit 5
The data read from a is demodulated by the data modulation / demodulation circuit 6 and sent to the data width conversion circuit 7.

The data width conversion circuit 7 deletes invalid upper bit data (0) from the data demodulated by the data modulation / demodulation circuit 6 and converts the remaining data into lower 3 bits (D00, D00).
D01, D02, D20, D21, D22,...) And the upper three bits (D10, D11, D12, D30, D31, D32,...) And send them to the host in a 3-bit width.

The data width conversion circuit 7 has a head number (head 1a in the above case) corresponding to the dummy value added when the parallel data from the host is converted for writing.
6, 1a7) are held in a holding circuit (not shown), and the contents of the holding circuit are used for conversion when transferring data to the host.

As described above, the data width conversion circuit 7 converts the m-bit width data sent from the host to the disk surfaces 2a to 2l in the magnetic disk device into n-bit width data, and the disk surfaces 2a to 2l By simultaneously writing data to n tracks using n heads 1a0 to 1a7,..., It is possible to speed up access to the disk surfaces 2a to 2l.

The same number of heads 1a0-1a as the number of tracks
a7,..., eliminates the need for seeking and eliminates mechanical parts related to seeking, thereby reducing the failure rate and improving the reliability of the entire magnetic disk drive. Can be done.

[0045]

As described above, according to the present invention, in a magnetic disk drive comprising a disk surface having a plurality of tracks, a plurality of heads are provided on the disk surface in correspondence with the plurality of tracks, respectively. After changing the data width of the data from the higher-level device according to the number of tracks on the disk surface, the data that is simultaneously written to the disk surface by a plurality of heads and simultaneously read from the disk surface by the plurality of heads is adjusted to the data width of the upper-level device By transferring the data after the change, it is possible to increase the speed of disk access and to improve the reliability of the entire apparatus.

[Brief description of the drawings]

1A is a sectional view of a disk surface according to an embodiment of the present invention, and FIG. 1B is a plan view of the disk surface according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a magnetic disk drive according to one embodiment of the present invention.

FIG. 3 is a diagram showing a relationship among a head, a track, and a sector in one embodiment of the present invention.

FIG. 4A is a diagram showing an example of data sent from a host to a magnetic disk drive according to one embodiment of the present invention;
(B) is a diagram showing an example of writing the data sequence of (a) to the disk surface.

[Explanation of symbols]

 1a to 1l Head unit 1a0 to 1an head 2 Disk medium 2a to 2l Disk surface 3 Selector circuit 4 Motor 5 Write / read circuit 6 Data modulation / demodulation circuit 7 Data width conversion circuit

Claims (4)

[Claims] 1. A magnetic disk drive comprising a disk surface having a plurality of tracks, comprising: a plurality of heads disposed on the disk surface corresponding to each of the plurality of tracks; The data width is changed according to the number of tracks on the disk surface, and then the data simultaneously written to the disk surface by the plurality of heads and simultaneously read from the disk surface by the plurality of heads is changed to the data width of the host device. And a means for transferring data after the transfer. 2. A magnetic disk comprising: a plurality of disk surfaces each having a plurality of tracks; and a selector circuit for selecting one of the plurality of disk surfaces when performing data transfer with a host device. A plurality of heads arranged corresponding to each of the plurality of tracks on each of the plurality of disk surfaces, and changing a data width of data from the host device according to the number of tracks on the disk surface. Means for simultaneously writing data on the disk surface with the plurality of heads and simultaneously changing data read from the disk surface with the plurality of heads to the data width of the host device, and transferring the data. Magnetic disk drive. 3. A magnetic disk drive comprising a disk surface having n (n is a positive integer) tracks, wherein the n disks are arranged on the disk surface in correspondence with the n tracks. And n bits of data (m is a positive integer, m ≦ n) from the host device are changed to n bits of data, and then simultaneously written to the disk surface by the n heads and the n Means for changing the n-bit data read simultaneously from the disk surface by the head to m-bit data and transferring the data to the host device. 4. When data transfer is performed between l (l is a positive integer) disk surfaces each having n (n is a positive integer) tracks and the upper device, A magnetic disk drive comprising: a selector circuit for selecting one of the disk surfaces; n heads disposed corresponding to each of the n tracks on each of the l disk surfaces; M bits (m is a positive integer,
m ≦ n) is changed to n-bit data, then n is simultaneously written to the disk surface by the n heads and n is simultaneously read from the disk surface by the n heads
Means for changing bit data to m-bit data and transferring the data to the higher-level device.