JPH04291005A - Magnetic head selection system for magnetic disk device - Google Patents

Abstract

PURPOSE:To prevent time loss due to the tracking adjustment. CONSTITUTION:Magnetic heads with an even head number are attached to a head arm 16 and the magnetic heads with an odd head number are attached to a head arm 26. The head number assigned by a controller 1 is stored in a head number register 3 and an adder 4 adds '1' to the number. A first gate 10 selects the head number with an even head number from among head numbers A and B outputted by the register 3 and the adder 4, and outputs a signal for selecting the magnetic head to a first head selector 11. The selector 11 gives servo information read out with the magnetic head to a first signal controller 13, and a first servo control part 14 controls a first head driving part 15 based on the information, adjusts the head position and conducts tracking. At the same time, a second gate 20 selects the odd number from among the head numbers A and B, and outputs the signal for selecting the magnetic head to a second head selector 21. Similarly, the tracking of the selected magnetic head is performed.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head selection method for a magnetic disk device, and more particularly to a so-called sector servo type magnetic disk in which a data recording area and a recording area for controlling a servo mechanism are mixed on a user track. This relates to the magnetic head selection method of the device.

0002

2. Description of the Related Art Conventionally, an actuator of a magnetic disk drive, that is, a mechanism for mechanically and electrically driving a read/write magnetic head, is recognized as one volume by software that accesses the magnetic disk drive. When software accesses data in this volume, one magnetic head is designated and one magnetic head possessed by the actuator is selected. When an I/O channel command regarding data reading/writing is issued from the CPU to the magnetic disk device via the controller, the data reading/writing is performed through the above-described selected magnetic head. At this time, depending on the I/O channel command, data reading/writing may be performed continuously across multiple tracks, that is, multiple magnetic heads.

Conventionally, one of the plurality of magnetic heads possessed by an actuator is assigned to control the servo mechanism, and is used to follow the magnetic heads of the entire actuator and position it on a desired track. .

0004

By the way, as a method of increasing the storage capacity of a magnetic disk storage medium, there is a method of increasing the total number of tracks by reducing the interval between adjacent tracks. However, when this method is used, tracking accuracy becomes a problem, and the magnetic head must be controlled so as to be positioned precisely on a designated track.

In conventional magnetic disk drives, the magnetic head for controlling the servomechanism and the magnetic head for data access are physically separated, and the magnetic head is physically separated from the magnetic head for data access. It was difficult to obtain tracking accuracy.

The sector servo system was devised to solve this problem, and in this system, access for servomechanism control and access for data writing/reading are performed by the same magnetic head. , tracking accuracy can be improved and track spacing can be reduced.

However, as tracking accuracy improves,
Since tracking adjustment processing is required for each magnetic head, when reading/writing data continuously across multiple tracks as described above, the tracking adjustment time immediately after track switching becomes shorter as a result. This may result in a loss of time equivalent to one rotation.

An object of the present invention is to solve such problems and to prevent time loss associated with tracking adjustment processing even when data is read/written continuously across a plurality of tracks. An object of the present invention is to provide a magnetic head selection method for a magnetic disk device.

[0009]

[Means for Solving the Problems] The present invention provides a plurality of magnetic disk storage media attached to the same rotating shaft, a plurality of magnetic disk storage media that performs recording and reproduction on these storage media, and a plurality of magnetic disks each having a predetermined head number. a first drive unit that drives the magnetic heads with even head numbers; a second drive unit that drives the magnetic heads with odd head numbers; a register that holds the head number from the controller; and a register that adds 1 to the head number output by this register and outputs the result. an adder; and a first selector for selecting one magnetic head from among the magnetic heads with even head numbers to perform recording and reproduction on the storage medium based on the given head number.
head selection means, and a second head selection for selecting one magnetic head for recording and reproducing on the storage medium from among the magnetic heads having odd head numbers, based on the given head number. and when the head number outputted by the register is an even number, the head number is outputted to the first head selection means, and when the head number outputted by the register is an odd number, the head number is outputted to the first head selection means. The present invention is characterized in that it is provided with a gate means for outputting to the second head selection means.

0010

[Example] Next, an example of the present invention will be described. Figure 1
1 shows an example of a magnetic disk device constructed based on the magnetic head selection method according to the present invention. The magnetic heads of this magnetic disk device are divided into those with even numbered head numbers and those with odd numbered head numbers. The magnetic heads with even head numbers are attached to the head arm 16 and access the magnetic disk storage medium 12, while the magnetic heads with odd head numbers are attached to the head arm 26 and access the magnetic disk storage medium 22. access.

Each head arm 16, 26 has a first
and is driven by second head drive sections 15 and 25. The first and second signal control units 13 and 23 receive information read from the respective storage media 12 and 22 by the magnetic heads through first and second head selectors, which will be described later, and the data recorded in each sector will be described later. Data converter 5
On the other hand, servo information is output to the first and second servo control sections 14 and 24, respectively. The first and second servo controllers 14 and 24 are signal controllers 13 and 2, respectively.
When receiving servo information from 3, it decodes it. Then, it is determined whether or not the magnetic head is correctly positioned on the track, and if it is off the track, a control signal is output to the head drive units 15 and 25, respectively, to move the head arms 16 and 26, Adjust the position of the magnetic head.

When the controller 1 outputs the number of the magnetic head that is to perform recording and reproduction on the magnetic disk storage medium, the head number register 3 receives it through the interface control unit 2, holds it, and outputs it as a head number A. . Adder 4 adds 1 to head number A output from register 3, and outputs the result as head number B.

The first gate 10 receives the head numbers A and B, selects an even head number, and outputs a signal for selecting the magnetic head of that number to the first head selector 11. On the other hand, the second gate 20 receives the head numbers A and B, selects an odd head number, and outputs a signal for selecting the magnetic head of that number to the second head selector 21. The first head selector 11 is a head arm 1
The magnetic head indicated by the signal output from the gate 10 is selected from among the magnetic heads mounted on the magnetic head 6 as the magnetic head that accesses the medium 12. On the other hand, the second head selector 21 selects the magnetic head indicated by the signal output from the gate 20 from among the magnetic heads mounted on the head arm 26 as the magnetic head that accesses the medium 22.

The data conversion section 5 receives the value of the least significant bit of the head number output from the register 3, and determines whether the head number is an even number or an odd number. If the number is even, the signal control unit 1
On the other hand, if the number is an odd number, data can be transmitted and received between the signal control unit 23 and the interface control unit 2.

Next, the operation will be explained. Controller 1 is
When the head number of the magnetic head accessing the storage medium 12, 22 is output, the register 3 receives it through the interface control section 2, holds it, and outputs it as head number A. Adder 4 receives this head number A, adds 1 to it, and outputs it as head number B. Here, if head number A is an even number, gate 1
0 outputs a signal for selecting the magnetic head with head number A to the selector 11, and gate 20 outputs a signal for selecting the magnetic head with head number B to the selector 21.

Then, the selector 11 selects the magnetic head with head number A, and outputs the information read from the medium 12 by the magnetic head to the signal control section 13. Signal control section 13
Of the received information, the data is outputted to the data conversion section 5, and the servo information is outputted to the servo control section 14. When the servo control unit 14 receives this servo information, it decodes it. Then, it is determined whether the magnetic head is correctly positioned on the track, and if it is off the track, a control signal is output to the head drive section 15 to move the head arm 16, and the magnetic head of the head medium A is moved. Adjust the head position.

On the other hand, the selector 21 selects a magnetic head and outputs the information read from the medium 22 by the magnetic head to the signal control section 23. Of the received information, the signal control section 23 outputs data to the data conversion section 5 and outputs servo information to the servo control section 24 . When the servo control section 24 receives this servo information, it decodes it. Then, it is determined whether the magnetic head is correctly positioned on the track or not, and if it is off the track, a control signal is output to the head drive section 25 to move the head arm 26 and change the position of the magnetic head. adjust.

Further, when head number A is an odd number, gate 10 outputs a signal for selecting the magnetic head with head number B to selector 11, and gate 20 selects the magnetic head with head number A. A signal for this purpose is output to the selector 21. Thereafter, the position of each magnetic head is adjusted in the same manner, and the data read from the media 12 and 22 is sent to the data conversion section through the signal control sections 13 and 23, respectively.

Therefore, in this magnetic disk device, the tracking control of the magnetic head with head number A is performed to access the corresponding storage medium, and at the same time, the tracking control of the magnetic head with head number B, which is one larger than head number A, is also performed in parallel. will be carried out. Therefore, when the controller 1 subsequently specifies the next head number, that is, head number A+1 (that is, head number B), tracking control for that magnetic head has already been completed.

The data converter 5 receives the value of the least significant bit of the head number output from the register 3, and determines whether the head number is an even number or an odd number. If the number is even, the signal control unit 1
On the other hand, if the number is odd, data can be transmitted and received between the signal controller 23 and the interface controller 2. As a result, the controller 1 can receive data from the magnetic head with the designated head number, and can also write data through the designated magnetic head.

Note that the first and second gates 10 and 20 can be specifically constructed by a circuit as shown in FIG. In the figure,
A2n represents each bit of the binary head number A output from the register 3, and B2n represents each bit of the binary head number B output from the adder 4. In this example, it is assumed that the outputs of register 3 and adder 4 are 5 bits. Therefore, n takes a value of 0 to 4.

First, gate 10 will be explained. Four AND circuits including AND circuits 101 and 103 perform an AND operation between bits B21 to B24 of head number B and bit A20 of head number A. On the other hand, AND circuit 102
, 104, bits A21 to A
24 and an inverting circuit (INV) whose input is bit A20.
AND with the inverted output A20 of 30 is taken. Then, the OR circuit 105 performs an OR operation on the outputs of the AND circuits 102 and 101 which input bits A21 and B21, and provides the result to the selector 11 as bit C21 of the output of the gate 10. Similarly, the other OR circuits also have bits A22 and B2, respectively.
2 is taken as an input, and the result is given to the selector 11 as bit C22 of the output of gate 10. Bit C of the output of
23 to the selector 11, and the OR circuit 106
is an AND circuit 104 whose inputs are bits A24 and B24.
, 103 and provides the result to the selector 11 as bit C24 of the output of the gate 10.

[0023] When head number A is an even number, bit A2
Since 0=0 and its inverted value is A20=1, the output of the AND circuit with bits B21 to B24 as input is 0.
The bits A21 to A24 are output as they are from the AND circuit which receives the bits A21 to A24 as input. Therefore, the four OR circuits output bits A21 to A24 as signals for selecting the magnetic head. on the other hand,
When head number A is an odd number, bit A20=1 and its inverted value A20=0, so bits A21 to A
The output of the AND circuit that inputs bits B24 is 0, and the output of the AND circuit that inputs bits B21 to B24 outputs bit B.
21 to B24 are output as they are. Therefore, the outputs B21 to B24 of the adders are output from the four OR circuits as signals for selecting a magnetic head.

On the other hand, in the gate 20, an AND circuit 201
, 203, bits B21 to B
24 and an inverting circuit (INV) whose input is bit A20.
31 with the inverted output A20, AND circuit 2
The four AND circuits containing 02, 204, bit A21
.about.A24 and bit A20 are ANDed. Therefore, when head number A is an even number, the four OR circuits including OR circuits 205 and 206 output bits B21 to B24 to the selector 21 as signals for selecting the magnetic head.
On the other hand, when head number A is an odd number, bits A21 to A2
Outputs 4.

Note that this magnetic disk device is equipped with two head drive units (actuators) 15 and 25, but as can be seen from the above explanation, the controller 1 does not need to take this into consideration at all; All you need to do is specify the head number of the magnetic head. That is, externally, this magnetic disk device is no different from a magnetic disk device equipped with one actuator.

[0026]

As explained above, in the magnetic disk drive based on the magnetic head selection method of the present invention, the magnetic heads are divided into even numbered heads and odd numbered heads, and the magnetic head of the head number specified by the controller is divided into even numbered heads and odd numbered heads. head and
Tracking control is performed simultaneously on the magnetic head with the next head number. Therefore, when the controller specifies the next head number, tracking control for that magnetic head has already been completed, and data can be read or written immediately.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an example of a magnetic disk device based on the magnetic head selection method of the present invention.

FIG. 2 is a block diagram showing in detail a part of the magnetic disk device in FIG. 1;

[Explanation of symbols]

1 Controller 2 Interface control section 3 Head number register 4 Adder 5 Data conversion section 10 First gate 11 First head selector 12, 22 Magnetic disk storage medium 13 First signal control section 14 First servo control section 15 First head drive section 16, 26 head arm 20 Second gate 21 Second head selector 23 Second signal control section 24 Second servo control section 25 Second head drive section

Claims (1)

[Claims] 1. A plurality of magnetic disk storage media attached to the same rotating shaft, and a plurality of magnetic heads that perform recording and reproduction on these storage media and are each given a predetermined head number, A magnetic disk device that receives the head numbers of the magnetic heads that perform recording and reproduction on a storage medium from a controller includes a first drive unit that drives the magnetic heads whose head numbers are even numbers, and a first drive unit that drives the magnetic heads whose head numbers are odd numbers. a second drive unit that drives the magnetic head; a register that holds the head number from the controller; an adder that adds 1 to the head number output from the register; a first head selection means for selecting one magnetic head for recording and reproducing on the storage medium from among the magnetic heads having an even head number based on the head number; a second head selection means for selecting one magnetic head for recording and reproducing on the storage medium from among the magnetic heads whose head numbers are odd numbers; gate means for outputting the head number to the first head selection means when , and outputting the head number to the second head selection means when the head number output from the register is an odd number. A magnetic head selection method for a magnetic disk device characterized by: