JPH087482A - Data recording/reproducing device and method of adjusting its circuit - Google Patents

Abstract

PURPOSE:To improve the format efficiency of a disk and to realize the execution of a filter adjustment processing of a read/write circuit even at the time of seek operation of a head by improving the recording position of the filter adjusting data. CONSTITUTION:In a disk format of a CDR system, the disk 4 recording the prescribed filter adjusting data in a servo area or between the servo area and a data area is used. In the read/write circuit 11, the prescribed filter adjustment of a waveform equalization circuit is executed according to the filter circuit adjusting data read by the head 1. Since the filter circuit adjusting data are provided at every servo area not at every data sector, the format efficiency is improved. Further, the recording position of the filter circuit adjusting data together with the servo area becomes the same position of respective zones also. Thus, the prescribed filter adjustment is executed by reading out the filter circuit adjusting data while the head passes through the different zone and moves to a target track.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk device, and more particularly to a data recording / reproducing device which employs a PRML system data recording / reproducing system.

[0002]

2. Description of the Related Art In recent years, especially hard disk devices (HD
In the magnetic disk device such as D), the recording density of the data recorded on the disk is increased with the increase of the storage capacity. As a technique for realizing this high recording density, P
A signal processing technique of a data recording / reproducing system called an R (Partial Response) system and an MR (mag)
A magnetoresistive reproducing head called a "netoresistive" type head is drawing attention.

The PR system includes PRML (Partial R) including the decoding process (data detection process) of the data reproduction system.
esponse Maximum Likelihoo
d) method, which is hereinafter referred to as PRML method. In this PRML type read / write circuit, information can be accurately reproduced even when the S / N ratio is low as compared with the conventionally known peak detection type.

On the other hand, the MR type head is a type of head which detects a magnetic field generated on the surface of the disk as a change in resistance value, and is highly sensitive to an inductive type thin film head and the like, and has a large reproduction signal. It has the advantage that it does not depend on the running speed of the disk. The MR type head is a reproducing head only for reading data. Therefore, a data recording / reproducing apparatus such as an HDD requires a recording head for writing data in addition to the MR head. In general, an inductive thin film head is used as a recording head, and a composite head having a composite head structure composed of this thin film head and an MR head is used.

As shown in FIG. 6, in the composite type head, the head width of the recording head 2 is generally wider than the head width of the MR reproducing head 1 as shown in FIG.
write / narrow row
d) method is adopted. Since the composite type head is composed of a combination of different head elements, particularly when a rotary type actuator is used as a moving mechanism of the head, the reproducing head 1 and the recording head 2 have an offset in the track direction. appear.

Therefore, during a read operation (data reproduction), an offset is added during head positioning control so that the reproducing head 1 is located at the track center n. During the write operation (data recording), as shown in FIG. 6, an offset is added so that the recording head 2 is located at the track center n. In FIG. 6, n
+1 and n-1 are the centers of the adjacent tracks.

Here, servo data is recorded in advance in servo areas radially provided on the disk.
Based on the servo data read by the reproducing head 1 from this servo area, a servo operation for positioning the head at the track center n of the target track is executed. Therefore, even during the write operation, the recording head 2 is positioned at the track center n based on the servo data read by the reproducing head 1. Therefore, during the write operation, the reproducing head 1 performs the read operation at a position offset from the track center n.

When the data read operation is executed with the reproducing head 1 offset as described above, the S / N ratio of the read signal is deteriorated. Therefore, the above PR
By adopting the data reproducing method of the ML method, the data error rate can be suppressed to a low level even if the S / N ratio of the reproduced signal is poor, and an accurate reproducing operation can be executed. Therefore, as a result, the S / N ratio during the servo data read operation can be improved.

[0009]

HDD with high recording density
MR-type head and PRML
A method combining a read / write circuit has attracted attention. By the way, in the PRML type read / write circuit, the waveform of the read signal output from the head is PR
A waveform equalization circuit is used for performing waveform equalization processing for equalizing (deforming) so as to have characteristics. The waveform equalizing circuit has a filter circuit that automatically adjusts filter parameters such as a cutoff frequency and a boost amount. Filter parameters are set for each HDD head or CD
In the case of the R method, it is necessary to set the optimum value for each zone. CDR (constant density re)
The cording method is a method in which a track group in the radial direction is divided into a plurality of zones and data is recorded so that the number of data sectors is different for each zone. That is, the data transfer rate is different for each zone.

Conventionally, filter adjustment data (hereinafter referred to as training data) for performing filter adjustment such as cutoff frequency and boost amount is recorded in advance on a disk, and this training data is used to filter a waveform equalizing circuit. There is a system where adjustments are made. That is, the reproducing head 1 reads the training data from the disk and applies it to a read / write circuit having a waveform equalizing circuit.

The read / write circuit compares the read waveform with the original waveform (standard waveform) of the training data (pattern) stored in advance, and based on the comparison result, cutoff frequency and boost amount. The adjustment processing of the filter parameters such as is automatically executed.

Here, the conventional training data includes a preamble (preamble) of an ID data part and a user data part of a data area formed in each track of the disc.
It is recorded in the part (several bytes) immediately after (le). Therefore, there are the following problems. Firstly, since an area for recording training data is provided for each data area (CDR type data sector), the format efficiency of the disk deteriorates. Secondly, in the CDR method, since the number of data sectors is different for each zone, the recording position of the training data becomes discontinuous when the head moves to the target track through different zones. Therefore, during the seek operation of the head, the reproducing head cannot completely read out a series of training data, and the filter adjustment processing is not executed.

Therefore, conventionally, when the filter adjustment is performed, it is necessary to perform the filter adjustment by reproducing the training data after reaching the target track, that is, after the head is stopped at the track. As a result, there has been a problem that the read / write processing is delayed.

It is an object of the present invention to provide a data recording / reproducing apparatus which solves the above-mentioned problems, by improving the recording position of the training data, the disk format efficiency is improved, and the training is performed during the seek operation of the head. It is to realize execution of filter adjustment processing based on data.

[0015]

According to the present invention, particularly in a data recording / reproducing apparatus such as a CDR type HDD, a servo in which servo data is recorded at the same position of each track included in each zone formed on a disk is provided. This is a device having a disc in which an area is provided and predetermined filter circuit adjustment data is recorded inside the servo area or between the servo area and the data area. Further, the present apparatus has a PRML-type read / write circuit having a waveform equalization circuit including a filter circuit for performing a predetermined filter adjustment according to the filter circuit adjustment data read by the head.
It has a light circuit.

[0016]

According to the present invention, in the disk format of the CDR system, a disk in which predetermined filter circuit adjusting data is recorded inside the servo area or between the servo area and the data area is used. The read / write circuit executes a predetermined filter adjustment of the waveform equalization circuit according to the filter circuit adjustment data read by the head. Since the filter circuit adjustment data is provided not for each data sector but for each servo area, the format efficiency can be improved. In addition to the servo area, the recording position of the filter circuit adjustment data is the same position in each zone. Therefore, it is possible to read the filter circuit adjustment data and execute the predetermined filter adjustment even during the movement of the head to move to the target track through different zones.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a block diagram showing a main part of an HDD according to the embodiment, FIG. 2 is a conceptual diagram for explaining a configuration of a disk format according to the embodiment, and FIG. 3 is a CDR-type disk format according to the embodiment. 5 is a conceptual diagram for explaining the configuration of FIG. 4, FIG. 4 is a conceptual diagram for explaining the configuration of the CDR type disc format according to the embodiment, and FIG.
3 is a flow chart for explaining the operation of the same embodiment. (Structure of HDD) As shown in FIG. 1, the HDD of the embodiment has a disk 4 of a disk format of a CDR system as described later, a composite type head 3 having an MR type head as a reproducing head 1, and a PRML system This is a data recording / reproducing apparatus which employs the read / write circuit 11 of

In the present embodiment, the number of the disk 4 which is the recording medium is one, and it is rotated at a high speed by the spindle motor 8. The spindle motor 8 is drive-controlled by the drive current supplied from the motor driver 9 under the control of the control circuit 10.

The composite type head 3 is a combination of the reproducing head 1 and the recording head 2 composed of a thin film head, and is provided corresponding to each side of the disk 4. Each composite head 3 has a rotary actuator 5
And is moved by the voice coil motor (VCM) 6 in the radial direction of the disk 4. The VCM 6 is drive-controlled by the drive current supplied from the VCM driver 7 under the control of the control circuit 10.

The read / write circuit 11 inputs a read signal (analog signal) read by the reproducing head 1 of the composite type head 3, generates read data (data pulse) from the read signal, and outputs the read data (data pulse) from the interface controller 14. Output to. In addition, the read / write circuit 11
Converts the recording data (write data) transferred from the interface controller 14 into a write signal (write current) and supplies it to the recording head 2 of the composite type head 3.

Further, the read / write circuit 11 reproduces the servo data recorded on the disk 4 and outputs it to the servo controller 12. The servo data is data for positioning control of the composite head 3, and is composed of a cylinder address code for speed control and burst data for position control.

The read / write circuit 11 comprises a PRML data recording / reproducing system, and has a waveform equalizing circuit including a filter circuit 11a as a part of the read circuit. The waveform equalization circuit performs waveform equalization processing for equalizing (modifying) the waveform of the read signal output from the reproducing head 1 so as to have a PR characteristic. As will be described later, the filter circuit 11a used in this waveform equalization circuit has training data (filter adjustment data) pre-recorded on the disk 4.
Accordingly, a circuit in which adjustment of filter parameters such as cutoff frequency and boost amount (hereinafter referred to as filter adjustment) is automatically executed is assumed. The read circuit has various circuits such as an AGC amplifier and a read pulse generation circuit in addition to the waveform equalization circuit.

The interface controller 14 has an H
It constitutes an interface between the DD and the host computer, and exchanges read / write data and various interface signals. The CPU 13 is a microprocessor (microcontroller) for controlling each component of the HDD according to an instruction from the interface controller 14. In this embodiment, the CPU 13 executes positioning control (seek control and position control) of the head 3, and also performs filter adjustment control during seek control (see FIG. 5).

The servo controller 12 reproduces the cylinder address code and burst data of the servo data from the output signal of the read / write circuit 11 and outputs it to the CPU 13. Further, the servo controller 12 has a sector pulse generation circuit 12a that generates a servo sector pulse from the sector pattern data of the servo data. The servo controller 12 outputs the generated servo sector pulse to the CPU 13 and the read / write circuit 11. CP
U13 is a servo sector pulse and read / write circuit 1
A data sector pulse for detecting a data sector is generated based on the split information reproduced by 1. The split information is information recorded in the servo area SA and is information indicating the format of each data sector for each zone in the CDR system (see FIG. 3).

The CPU 13 executes seek control (speed control) for moving the head 3 to the target track based on the cylinder address code output from the servo controller 12. Further, the CPU 10 determines, based on the burst data output from the servo controller 12,
Position control is performed to position the reproducing head 1 or the recording head 2 of the head 3 at the center of the target track.

Next, the operation of the embodiment will be described. (CD
Basic Operation of R Method) First, in the CDR method, the format of the disk 4 is
As shown in FIG. 3, servo areas (SA0 to SA7) and zones (Z0 to Z3) radially arranged at a predetermined interval.
Data sectors with different numbers of sectors (DS0, DS1,
DS2 ...). Each zone (here, four zones for convenience) includes several tens to several hundreds of tracks (cylinders). Each zone has a servo area (SA
0 to SA7) are recorded at the same position, and the number of servo sectors based on this servo area is the same. On the other hand, the number of sectors of a data sector (data area) for recording / reproducing user data differs for each zone. That is, the number of sectors in the outermost zone Z0 is maximum, and the number of sectors in the innermost zone Z3 is minimum. With such a format configuration, the data transfer rate of data is different for each zone, but the recording density is made uniform.

As shown in FIG. 2, the servo area includes burst data and sector patterns (index patterns).
An area 20 in which servo data such as data and cylinder code is recorded, a preamble (PA) 21, training data 22 according to the present invention, SYNC data 23, various data 24, and an error code (ECC) 25. That is, when the track is roughly divided into a servo area and a data area (data sector), the training data 22 is recorded inside the servo area in the present invention.
When the area in which the servo data is recorded is the servo area, the training data 22 is recorded between the servo area and the first data area of the servo sector in the present invention.

The various data 24 are contents corresponding to conventional ID data, such as sector numbers and split information. The data area includes a preamble (PA) 26 and a user data area 27 for recording user data.

When the CPU 13 receives an access command from the host computer through the interface controller 14, the CPU 13 executes positioning control for positioning the head 3 on a target track (a track including a data sector to be accessed). In this positioning control, the CPU 13
Executes seek control for moving the head 3 to the target track (step S1 in FIG. 5). Playback head 1
Reads servo data from the servo area while seeking in the radial direction of the disk 4.

The servo controller 12 causes the sector pulse generation circuit 12a to generate a servo sector pulse SS based on the servo data read from the reproducing head 1 (step S2). As shown in FIG.
In the write circuit 11, when the read gate RG becomes active after the servo sector pulse SS is generated from the servo controller 12, the read signal from the reproducing head 1 receives the preamble (PA) 21 and the training data 2.
2, SYNC data 23, and various data 24 are input in this order.

The CPU 13 detects the current track position of the head 3 during the seek operation based on the cylinder code of the servo data (step S3). Based on the detected current track position, speed control for moving the head 3 to the target track is executed. When the head 3 reaches the target track, the CPU 13 positions the reproducing head 1 at the center of the target track if the access command is a read operation. If the access command is a write operation, the recording head 2 is positioned at the center of the target track.

In this state, the CPU 13 determines the data sector pulse D corresponding to each zone based on the generated servo sector pulse SS and the split information of the various data 24.
Generate S (see FIG. 2). At the timing of this data sector pulse DS, the read / write circuit 11
User data recording or reproducing operation is executed for the data area (YES in step S7, S10). (Filter adjustment operation) In the basic operation as described above,
In the embodiment, the training data 22 is read by the reproducing head 1 and input to the read / write circuit 11. In the read / write circuit 11, the filter adjustment of the filter circuit 11a of the waveform equalization circuit is executed by the read training data 22 (step S5).
That is, during data reproduction, the read circuit of the read / write circuit 11 executes appropriate waveform equalization processing according to the zone to be read and the characteristics of the reproducing head 1.

Here, in the embodiment, the training data 22 is not in the data area, as shown in FIG.
It is recorded in the servo area or between each area. Therefore, like the servo data, the training data 22 is recorded at the same position in each zone (linearly over all tracks in each zone). Therefore, even during the seek operation of the head 3, the reproducing head 1 can continuously read the training data 22 of each track. Even if the seek operation is not in progress, a series of training data 22 is continuously read and the filter adjustment is executed.

By the way, as shown in FIG. 4 (the dotted line shows the magnetization reversal position), the recording frequency of the training data 22 is usually different depending on each zone. In this case, the servo data has the same recording frequency in each zone. Therefore, it is not desirable to perform the filter adjustment of the read / write circuit 11 by the training data 22 other than the zone of the target track.

Therefore, in the present embodiment, the CPU 13 determines, based on the current track position of the head 3 during the seek operation,
It is determined whether or not the zone to which the target track belongs (step S4). If the head 3 has reached the zone to which the target track belongs, the CPU 13 executes the filter adjustment processing based on the read training data 22 as described above (YES in step S4, S
5). As a result, the read / write circuit 11 can also perform the data reproduction process according to the PRML method for the various data 24 read by the reproduction head 1.

On the other hand, if the result of the determination shows that the position of the head 3 is within the zone unrelated to the target track, the CPU 1
3 prohibits execution of the filter adjustment processing in the read / write circuit 11 (NO in step S4, S8). And
When the head 3 reaches the zone to which the target track belongs,
The prohibition is released and the filter adjustment processing is executed (YES in step S9).

As described above, the read / write circuit 11
The training data 22 for filter adjustment is recorded in the servo area or its vicinity instead of the data area and ID area as in the conventional case. Therefore, in the same zone, the filter adjustment process can be executed during the seek operation based on the training data 22 read by the reproducing head 1. Therefore, since there is a high possibility that the filter adjustment can be completed before the head 3 reaches the target track, even if the filter adjustment takes a long time in a low S / N state, the PRML is started immediately after the head 3 reaches the target track. The data reproduction process according to the method can be executed.

Further, since it is not necessary to provide the training data 22 for filter adjustment for each data sector as described above, the efficiency of the data sector format of the disk 4 can be improved. That is, since the recording area for several bytes required for the training data 22 can be omitted from each data sector, the recording density of user data can be increased.

Further, as shown in FIG. 2, various data 24
By recording the training data 22 before
It is possible to read various data 24 after the filter adjustment. In other words, the data such as the sector number and the split information can be recorded / reproduced by the PRML method. This makes it possible to improve the S / N ratio during the read operation of various data 24 even if the data read operation is executed with the reproducing head 1 being offset. Conventionally, since the training data 22 is recorded in the data sector, the various data 24 are subjected to the reproduction processing by the conventional peak detection method. Therefore, when the data read operation is executed with the reproducing head 1 being offset, the S / N ratio during reproduction may deteriorate. The various data 24 also include ID data, defect map information (information indicating a defective sector and its replacement sector), and the like.

[0040]

As described above in detail, according to the present invention, it is possible to record the training data for filter adjustment in the servo area or its vicinity in a data reproducing / recording apparatus such as a magnetic disk apparatus adopting the PRML system. As a result, first, the area of the training data provided for each data sector can be omitted, so that the format efficiency of the disk can be improved. Secondly, when applied to the CDR method, if it is within the same zone, the filter adjustment processing based on the training data can be executed during the seek operation. Therefore, immediately after the target track is reached, the data reproduction process can be executed by the read circuit after the filter adjustment. Third, by recording various data after the training data,
Various data can be recorded / reproduced by the PRML system.

[Brief description of drawings]

FIG. 1 is a block diagram showing a main part of an HDD according to an embodiment of the present invention.

FIG. 2 is a conceptual diagram for explaining a disk format configuration according to the embodiment.

FIG. 3 is a conceptual diagram for explaining a configuration of a CDR type disc format according to the embodiment.

FIG. 4 is a conceptual diagram for explaining a configuration of a CDR type disc format according to the embodiment.

FIG. 5 is a flowchart for explaining the operation of the embodiment.

FIG. 6 is a conceptual diagram for explaining a data recording / reproducing operation by a conventional composite head.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Reproducing head, 2 ... Recording head, 3 ... Composite type head, 4 ... Disk, 11 ... Read / write circuit, 11a
... Filter circuit of waveform equalization circuit, 12 ... Servo controller, 13 ... CPU, 14 ... Interface controller.

Claims (6)

[Claims] 1. A head for recording / reproducing data, a data area recorded / reproduced by the head on each track, and a servo area in which servo data used for positioning control of the head are recorded at predetermined intervals. A disk having predetermined circuit adjustment data recorded in or near the servo area, a read circuit for executing reproduction processing of a read signal read from the disk by the head, and data to the disk. A read / write circuit having a write circuit that executes a recording process for recording, and the read circuit is provided with a predetermined circuit that requires a predetermined circuit adjustment according to the circuit adjustment data read by the head. A data recording / reproducing apparatus comprising: circuit means. 2. A head for recording / reproducing data and a group of tracks arranged in the radial direction are divided into a plurality of zones, which are used for positioning control of the head at the same position of each track included in each zone. Servo area where servo data to be recorded is recorded at a predetermined interval,
A CDR system in which the number of data sectors composed of data areas recorded and reproduced by the head formed on each track is different for each zone, and a predetermined value is provided inside the servo area or between the servo area and the data area. A disk on which the circuit adjustment data is recorded, a read circuit for executing a reproducing process of a read signal read from the disk by the head, and a write circuit for executing a recording process for recording data on the disk. Read / write circuit means provided with a predetermined circuit that requires a predetermined circuit adjustment in accordance with the circuit adjustment data read by the head. Recording / playback device. 3. A head for recording / reproducing data and a group of tracks arranged in a radial direction are divided into a plurality of zones, which are used for positioning control of the head at the same position of each track included in each zone. Servo area where servo data to be recorded is recorded at a predetermined interval,
A CDR system in which the number of data sectors composed of data areas recorded and reproduced by the head formed on each track is different for each zone, and a predetermined value is provided inside the servo area or between the servo area and the data area. Of the filter circuit adjustment data, a read circuit for executing reproduction processing of a read signal read from the disk by the head, and a write circuit for executing recording processing for recording data on the disk. And a read circuit provided with a filter circuit for executing a predetermined filter adjustment according to the filter circuit adjustment data read by the head.
A data recording / reproducing apparatus comprising: a write circuit means. 4. A head for recording / reproducing data and a group of tracks arranged in a radial direction are divided into a plurality of zones, which are used for positioning control of the head at the same position of each track included in each zone. Servo area where servo data to be recorded is recorded at a predetermined interval,
It is a CDR system in which the number of data sectors consisting of a data area recorded and reproduced by the head formed on each track is different for each zone, and a waveform is formed inside the servo area or between the servo area and the data area. A disk on which filter circuit adjustment data for performing a predetermined filter adjustment of a filter circuit used in an equalization circuit is recorded, and a PRML system for executing a reproducing process of a read signal read from the disk by the head. Read circuit and a write circuit that executes a recording process for recording data on the disk, and the predetermined filter adjustment is executed on the read circuit according to the filter circuit adjustment data read by the head. Read / write circuit provided with the waveform equalization circuit including a filter circuit And a data recording / reproducing apparatus. 5. A head for recording / reproducing data and a group of tracks arranged in the radial direction are divided into a plurality of zones, which are used for positioning control of the head at the same position of each track included in each zone. Servo area where servo data to be recorded is recorded at a predetermined interval,
The number of data sectors composed of data areas recorded / reproduced by the head formed on each track is different for each zone by a CDR method, and a predetermined value is provided inside the servo area or between the servo area and the data area. A circuit on which circuit adjustment data is recorded, a read circuit for performing a reproduction process of a read signal read from the disc by the head, and a write circuit for performing a recording process for recording data on the disc. Read / write circuit means, wherein the read circuit is provided with a predetermined circuit that requires a predetermined circuit adjustment according to the circuit adjustment data read by the head; and the head based on the servo data. Head moves to the target track of the disk during seek control. A predetermined circuit adjustment of the read circuit according to the circuit adjustment data when reaching the zone to which the head belongs, and a circuit adjustment when the head is moving in a zone unrelated to the target track. A data recording / reproducing device, comprising: 6. A head for recording / reproducing data, and a track group formed in a radial direction are divided into a plurality of zones, which are used for positioning control of the head at the same position of each track included in each zone. Servo area where servo data to be recorded is recorded at a predetermined interval,
A CDR system in which the number of data sectors composed of data areas recorded and reproduced by the head formed on each track is different for each zone, and a predetermined value is provided inside the servo area or between the servo area and the data area. A disk on which the circuit adjustment data is recorded, a read circuit for executing a reproducing process of a read signal read from the disk by the head, and a write circuit for executing a recording process for recording data on the disk. And a read / write circuit means in which the read circuit is provided with a predetermined circuit that requires predetermined circuit adjustment according to the circuit adjustment data read by the head, A drive for moving the head to a target track on the disk based on the servo data. Starting the control, detecting the current track position of the head in the seek control, and determining whether or not the head has reached the zone to which the target track belongs based on the detected current track position. When the head has reached the zone to which the target track belongs based on the determination step and this determination result, a predetermined circuit adjustment of the read circuit is executed according to the circuit adjustment data, and the head is And a circuit adjusting method for a data recording / reproducing apparatus, which comprises the step of prohibiting execution of the circuit adjustment when moving in a zone unrelated to the target track.