JP2006031825A - Recording and reproducing control method, and recording and reproducing control apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent reduction of ECC capability caused by concentration of errors based on periodicity of error frequency. <P>SOLUTION: When the number of interleave and the physical position of codes are decided as arrangement of ECC, periodicity in a position on a recording medium about data errors is considered, and the number of errors to a specific code frame is not concentrated. Periodicity of occurrence distribution of sector errors is discriminated, the number of interleave is set variably in accordance with it, or an allocation order of an interleave code frame for each sector is set variably. Alternatively, a byte data arrangement order in interleave constitution in the sector is set variably on the basis of periodicity of byte error occurrence distribution, or byte data in the sector is divided into a plurality of blocks and the arrangement order of the blocks is set variably for each sector. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a recording / reproducing control method and a recording / reproducing control apparatus for controlling a data recording / reproducing operation with respect to a recording medium such as an HDD (hard disk drive).

JP 2002-175666 A JP 2002-245726 A

An HDD (Hard Disk Drive) is known as a magnetic recording type information recording apparatus.
The HDD drive unit accommodates several magnetic media as recording media and is rotated at high speed by a motor. Magnetic media such as iron oxide and cobalt chrome are applied to the magnetic media by plating or thin film formation.
Then, by scanning the magnetic head in the radial direction on the surface of the rotating medium, the magnetization corresponding to the data is generated on the medium, and writing or reading of the data can be performed.

Hard disks are already widespread. For example, as a standard external storage device for a personal computer, for installing various software such as an operating system (OS) and applications necessary for starting the computer, and for saving created / edited files A hard disk is being used. Usually, the HDD is connected to the computer main body via a standard interface such as IDE (Integrated Drive Electronics) or SCSI (Small Computer System Interface), and its storage space is an operating system such as FAT (File Allocation Table). Managed by a file system that is a subsystem of
Recently, the capacity of HDDs has been increasing, and with this, not only as a conventional auxiliary storage device for computers but also as a hard disk recorder for storing broadcast-received AV content, the application fields have expanded, It has begun to be used to record various contents.

Here, taking the case where it is used as an auxiliary storage device for a computer as an example, the physical formatting method of the hard disk and the data read / write operation to the hard disk will be briefly described.
A large number of “tracks” are formed concentrically on the hard disk as sections for recording data. Then, track numbers such as 0, 1,... Are assigned from the outermost periphery to the inner periphery. The greater the number of tracks on the disk surface, the greater the storage capacity of the media.

Further, each track is divided into “sectors” as unit areas. Normal data read / write operations on the disk are performed in units of sectors. Although the sector size differs for each medium, the hard disk sector is generally set to 512 bytes. Further, in consideration of the media usage efficiency, in order to make the recording density on each track substantially uniform, the number of sectors is increased toward the outer track having a longer circumference. This is called a “Zone Bit Recording” (Zone Bit Recording: ZBR) system.
When the zone bit recording method is adopted, the recording density on each track can be made almost uniform, but the data transfer rate for each track becomes non-uniform. The data transfer rate decreases as the disk moves in the inner circumferential direction.
FIG. 12 shows an example of the ZBR method.
In the example shown in the figure, the disk 21 is divided into three zones, and zones 0, 1, 2 and zone numbers are given in order from the outermost periphery. Each zone includes a plurality of tracks.
In FIG. 12, each zone is divided into sectors. In this case (as a schematic example only), zone 0 is composed of 32 sectors. Similarly, zone 1 is 16 sectors and zone 2 is 8 sectors. Each is composed. When switching zones, the disk rotation speed is fixed for a specific number of sectors, and the recording / reproducing clock is made variable so that the linear recording density is kept within a predetermined range and the storage capacity per disk is increased. It is determined.
Although the example of FIG. 12 is a schematic diagram, the zones set in the radial direction are set to 16 zones, for example, zone 0 to zone 15, and the number of sectors in one track is, for example, 300 to 700 sectors. Often considered as a degree.

  Also, in the case of an HDD configured by concentrically overlapping several media, it can be considered that the same numbered track of each media is arranged in a cylindrical shape, and this is called a “cylinder”. Each cylinder is assigned the same number as the track number, and cylinder 0, cylinder 1,. The plurality of heads inserted between the media always operate as one body and move between the cylinders.

As a system for designating (addressing) a target sector, a CHS system can be cited. This is a method of accessing desired data by designating PBA (Physical Block Address) on the disk in the order of C (Cylinder), H (Head), and S (Sector).
On the other hand, in the CHS system, there is a limit to the CHS parameters that can be specified on the computer main body side that operates as a host for the HDD, and it becomes impossible to cope with an increase in capacity of the hard disk. For this reason, an LBA (Logical Block Address) system is adopted. This expresses a cylinder number, a head number, and a sector number (CHS) by a logical serial number called LBA starting from 0.

  In the conventional HDD, in order to access the medium and read / write data, the magnetic head is first scanned on the medium in order to reach the track with the target sector. This is called a “seek” operation of the magnetic head. Next, in order to reach the target sector on the track, the medium rotates and waits until the target sector comes directly under the magnetic head. This is called “waiting for rotation”.

Many conventional HDDs have interfaces such as IDE and SCSI for the purpose of connecting to a computer. Then, the disk drive control from the computer main body has a basic operation of designating the LBA indicating the head sector and the number of sectors to be accessed using the command set defined by the interface.
In this case, on the HDD side, access can be made while creating from the designated head sector and creating a sequence for prefetching by predicting the sector to be accessed thereafter.
This pre-read operation is based on the premise that sectors having continuous addresses are allocated to a series of data. Normally, sectors having consecutive addresses exist in consecutive head numbers or track numbers.
When large-sized data is continuously written on the medium, the pre-read operation at the time of reading works effectively.

  As the capacity of the disk increases, the track density increases and the track width becomes extremely narrow. Therefore, in order to write and reproduce data accurately, positioning of the magnetic head requires high accuracy. Therefore, a servo technique is adopted in which the position of the magnetic head is always aligned with the center of the track. It is possible to check whether or not the magnetic head is at the center of the track by writing signals called “servo patterns” on each track at regular intervals and reading them with the magnetic head. The servo pattern is written with high accuracy in the manufacturing process of the HDD. For example, a signal for positioning the head, a cylinder number, a head number, and a servo number are written in the servo area.

FIG. 13 shows an example of the arrangement of servo areas in which servo patterns are written on the magnetic disk 21. The solid line in the radial direction in FIG. 13 indicates the servo area SRV (not the sector division as shown in FIG. 12).
In the example shown in FIG. 13, servo areas are arranged radially on the magnetic disk 21 as indicated by 32 solid lines in the radial direction. That is, the servo area SRV is formed regardless of the zones 0, 1, and 2 that are concentric circles. That is, in any zone, 32 servo areas are formed per track.

Track positioning control is performed by this servo area SRV. In other words, when the track trace by the magnetic head passes through the servo area SRV, it is possible to obtain information as to whether the track is turned on or off.
Here, it is assumed that the track position is shifted due to the addition of a disturbance such as vibration during data reading. When the track moves largely, the entire servo control is performed from the beginning. That is, the data reading is interrupted, and a necessary track is accessed again to read the data.
On the other hand, when the track is moved (shifted) within the predetermined range in the direction of the adjacent track with respect to the correct position, the data reading is continued as it is while controlling the track position.

Note that a range (SF section in the figure) between two servo areas SRV is also called a servo frame.
For example, when one sector is given by 512 bytes, the size per sector (sector size) is small compared to the capacity between two servo areas on a track, so there are a plurality of one servo frame SF. Sectors are arranged.
The arrangement of these sectors is mainly determined for each ZBR zone. That is, when the zone is switched, the number of sectors arranged in the servo frame SF is also different.
In FIG. 13, 32 servo areas SRV are formed per track as a schematic diagram, but in reality, there are many examples where 96 servo areas SRV are formed per track.
For example, if the number of sectors per track in a certain zone is 633, the number of sectors in one servo frame SF is 6.6.
Although it may be specified that an integer number of sectors are arranged in one servo frame SF, one sector may be arranged across two servo frames SF for effective use of the recording area. good. For this reason, the number of sectors in the servo frame may be 6.6.

Incidentally, interleaving is used as an ECC (Error Correcting Code) arrangement method used in a data recording / reproducing apparatus such as a hard disk drive (HDD). As an ECC code arrangement method using interleaving, the code length is limited by hardware. A general method is to determine the number of interleaves that is as close as possible to the maximum value by, and arrange the codes in order for each interleave.
For example, FIG. 14 shows an example of sector interleaving when one track includes 633 sectors. FIG. 14A shows 633 sectors t0 to t0 + 632 in one track. t0 to t0 + 632 is the LBA of the sector.
In the case where the code length maximum value is 255, in order to arrange 633 sectors, the number of interleaves (interleave depth) m = 3. That is, three code frames i0, i1, and i2 are formed. The code frame means a group of sectors in which each byte data in the sector belongs to the same RS code word.
Then, as shown in FIG. 14A, code frame numbers i0, i1, and i2 are assigned in order from the sector t0. In this case, the code frame number of each sector is given as a remainder obtained by dividing the difference between the LBA of the sector and the LBA (= t0) of the first sector by the interleave number m.
Then, as shown in FIG. 14B, the interleave configuration is formed as three code frames i0, i1, i2 each having a code length n = 211 (note that the code length n is obtained by dividing the number of sectors by the number of interleaves). Value).
For example, the code frame i0 is formed of 211 sectors, sectors t0, t0 + 3, t0 + 6... T0 + 630.
Then, ECC error correction processing is performed in each of the code frames i0, i1, and i2 formed in the vertical direction in FIG.

However, if the error to be corrected by ECC has periodicity, and the period coincides with the interleave period, or one of the periods is a constant multiple of the other period, errors are concentrated in a specific code frame. A phenomenon occurs.
For example, in an HDD system, error concentration occurs due to the periodicity of sector errors within a track and the periodicity of byte errors within a sector.

First, the periodicity within a track of sector errors in the HDD will be described.
FIG. 15A shows a summary of sector errors generated in the entire HDD with respect to the relative positions in the track with respect to the sectors per track of the HDD. Here, the sector error occurrence frequency is shown for each section obtained by dividing one track into 384 relative positions (LBA head is 0 and tail is 1) obtained from the logical address in the track where the sector error occurred.
From FIG. 15A, it can be seen that many sector errors occur near the beginning of the track.
FIG. 15 (b) shows a result of Fourier analysis of the results and a summary of the period of error occurrence. This represents the number of sector errors in one track as the number of track divisions where 1 track = 1 period. From this figure, the relationship between the number of track divisions and the error frequency can be seen from the sector error occurrence interval when one track is one cycle.
As shown in the figure, there is a peak error frequency when the track is divided into 96 parts.
The HDD used for this data measurement has 96 servo areas SRV per track, and the error frequency peak located at the track division number 96 in the figure is concentrated in the servo frame period. Indicates. Similarly, the peak of the error frequency located at the track division number 32 indicates that the occurrence of errors is concentrated at a period three times that of the servo frame.

  FIG. 16A shows an example in which the interleaving number m is determined by the general method described above. Here, in an HDD with 16 zones (zones # 0 to # 15), the number of sectors per track in each zone, the number of sectors per servo frame when there are 96 servo frames SF in the track, and the maximum code length In each code frame i (i0, i1,...) When the value is 255, the interleave number m for maximizing the code length n (code length) and the code length for each code frame (the code length is the number of sectors). Respectively).

For example, zone # 0 has 633 sectors per track, and the number of sectors in the servo frame SF is 6.6. In this case, in order to make the code length of the code frame as close to the maximum value 255 as possible, the number of interleaves m = 3, and the code frames i0, i1, and i2 each have a code length n of 211 sectors.
Further, for example, zone # 9 has 499 sectors per track, and the number of sectors in the servo frame SF is 5.2. In this case, in order to make the code length of the code frame as close to the maximum value 255 as possible, the number of interleaves m = 2, the code length n of the code frame i0 is 250 sectors, and the code length of the code frame i1 is 249 sectors. Become.

Among these, the code arrangement in the zone # 4 is shown in FIG. In this zone # 4, the number of sectors per servo frame is 6 and the number of interleaves m = 3. Therefore, in the case of the general code arrangement described in FIG. 14, the error occurrence period is an integral multiple of the interleave period (here, 2), and many errors occur in sectors included in the same code frame every six sectors.
That is, FIG. 15 shows that the error frequency is high in the period of the servo frame SF, but in the case of FIG. 16B, for example, sectors t0, t0 + 6, t0 + 12,. Is included in the same code frame i0.
That is, in a certain code frame, sectors having a high error occurrence probability are intensively included.

Here, such a state where many errors occur in a plurality of sectors included in the same code frame is called error concentration.
In zone # 4, since the number of sectors per track is 576, error concentration occurs for each code frame 96 times per track.
Similarly, in zone # 10, the number of sectors per servo frame SF is 5, the number of interleaves m is 2, and the error occurrence period is not an integral multiple of the interleave period. In contrast, 48 times of error concentration occur.
In zone # 13, the number of sectors per servo frame SF is 4, and the number of interleaves m is 2, and 96 times of error concentration occurs per track circumference for every 4 sectors.
In other zones, since the number of sectors per servo frame SF includes a decimal point, the error concentration period becomes the least common multiple with the number of sectors per interleave, and such a problem is relatively unlikely to occur.

If the number of errors increases beyond the error correction capability due to the error concentration in a specific code frame, the error correction by ECC does not function. That is, there is a problem that the original error correction capability cannot be exhibited due to error concentration.
The inability to demonstrate error correction capability directly leads to a decrease in recording / reproducing operation performance.

Next, periodicity within a sector of byte errors in the HDD will be described.
FIG. 17A shows an example of the relationship between relative byte error occurrence position and byte error occurrence frequency in a sector (1 sector = 512 bytes). The byte position here means a logical position where one sector is 512 bytes.
In the error distribution shown in the figure, the error frequency up to about 23% at the beginning of the sector is high, and conversely, the frequency of error occurrence decreases at about 30% at the end of the sector.
FIG. 17B shows an ECC configuration in units of one sector. In each sector, bytes 0 to 511 are arranged horizontally in order. Then, error correction is performed on the byte data having the code length n along the column in the figure. That is, error correction is performed at the same byte position in a plurality of sectors.
Then, as shown in FIG. 17A, the error distribution in the sector is biased, so that error concentration is likely to occur with respect to, for example, the first approximately 23% byte positions in the sector.
If the error ratio with respect to the code length exceeds the correction capability at the byte position where the error is concentrated, the error correction does not function, and in this case, there is a problem that the error correction capability cannot be exhibited.

  An object of the present invention is to prevent the error correction capability from being deteriorated due to error concentration as described above, and to improve the recording / reproducing operation performance by appropriate error correction processing.

  The recording / reproducing control method of the present invention includes a determination step for determining the periodicity of the error occurrence distribution in the data recording area of the recording medium, and the recording based on the periodicity of the error occurrence distribution obtained in the determination step. A setting step for setting an interleave configuration of data to be recorded / reproduced to / from the medium, and an error correction process using the interleave configuration set in the setting step at the time of recording / reproducing data to / from the recording medium. And a recording / reproduction control step for controlling.

  Further, the recording / reproducing control apparatus of the present invention is based on the discriminating means for discriminating the periodicity of the error occurrence distribution in the data recording area of the recording medium and the periodicity of the error occurrence distribution grasped by the discriminating means Setting means for setting an interleave configuration of data to be recorded / reproduced to / from the recording medium, and executing error correction processing using the interleave configuration set by the setting means at the time of recording / reproducing data to / from the recording medium Recording / reproducing control means for controlling the recording / reproducing operation.

In the recording / reproducing control method and the recording / reproducing control apparatus, when the recording medium is a disk recording medium in which concentric or spiral tracks are formed and a plurality of zones are set in the radial direction, The periodicity of the error occurrence distribution is determined for each zone, and an interleave configuration is set for each zone based on the periodicity of the error occurrence distribution determined for each zone.
In addition, when the recording medium is a disk recording medium in which concentric or spiral tracks are formed and each of the tracks is divided into a plurality of sectors, the period of occurrence distribution of sector errors in the track The sector interleaving configuration is set based on the periodicity of the sector error occurrence distribution. For example, the number of interleaves is variably set, or the allocation order of interleave code frames for each sector is variably set.
When the recording medium is a disk recording medium in which concentric or spiral tracks are formed and each track is divided into a plurality of sectors, the periodicity of the occurrence distribution of byte errors in the sectors And the interleave configuration in the sector is set based on the periodicity of the byte error occurrence distribution. For example, the byte data arrangement order for each sector is variably set, or the byte data in the sector is divided into a plurality of blocks, and the arrangement order of the blocks is variably set for each sector.

That is, according to the present invention, when determining the interleave number and the physical position of the code (code) as the ECC arrangement, the error number is concentrated on a specific code frame in consideration of the periodicity of the data error at the position on the recording medium. Do not.
For example, when recording / reproducing with a disk recording / reproducing apparatus such as an HDD, it is common to use a plurality of physically continuous sectors in a track as a data access unit. Errors that occur frequently occur at a specific period such as the servo frame interval. When interleaving of sectors in a track is set here, generally, the number of interleavings that maximizes the code length is determined, and codes (sector data) are arranged in order for each interleaved code frame. When data in a cycle in which the code arrangement of each code frame coincides with the least common multiple of the cycle of the error occurrence position is present in the disk, errors are concentrated in a specific code frame.
Therefore, in order to avoid the occurrence of error concentration, the number of interleaves is increased or decreased, and the code arrangement of each code frame at the time of interleaving is varied to reduce periodicity.
In other words, if the number of errors increases beyond the error correction capability due to the error concentration in a specific code frame, error correction by ECC does not function, but even the same number of errors is distributed for each code frame. If the ratio of error to code length is within the correction capability in any code frame, error correction by ECC is effective, and an interleave configuration is set so that errors do not concentrate on a specific code frame.

According to the present invention described above, ECC can be set in consideration of error periodicity in a recording / reproducing system such as an HDD, and the number of errors in ECC units can be averaged to reduce the maximum value.
As a result, it is possible to avoid a decrease in error correction capability due to error concentration and to obtain a large margin for errors. In addition, when the margin is increased, for example, the number of ECC parity can be reduced, and the user data area can be expanded and the data capacity can be increased by reducing the parity. In that case, there are also advantages such as an increase in transfer rate and an increase in data density.

Hereinafter, embodiments of the present invention will be described in the following order with reference to the drawings.
1. 1. Configuration of hard disk device 2. Setting of interleave configuration in consideration of error periodicity 2-1. Setting of interleaving of sector 2-2. Setting of interleaving of byte data in sector 3. 3. Interleave configuration setting process example 3-1 Sector interleave setting process 3-2 Interleave setting process for byte data in a sector Modified example

1. Hard disk unit configuration

FIG. 1 schematically shows an overall configuration of an HDD (Hard Disk Device) 10 according to an embodiment of the present invention.
The HDD 10 of this example is a storage device having the camera unit 50 as a host device, for example. The AV stream data supplied from the camera unit 50 is recorded, and the reproduced AV stream data is supplied to the camera unit 50. The camera unit 50 has, for example, an imaging function and a playback video display function.
Actually, it is conceivable that the HDD 10 of this example is an HDD built in the camera apparatus or an apparatus connected to the camera apparatus for recording and reproducing video data.
The system connected to the camera unit 50 is merely an example. For example, the HDD 10 of this example may be built in or connected to other AV (audio / visual) devices, personal computers, game devices, or the like.

  As shown in the figure, the HDD 10 includes a CPU (Central Processing Unit) 11, a ROM (Read Only Memory) / RAM (Random Access Memory) 12, a disk controller 13, a buffer RAM 14, a data read / write control unit 15, and the like. , A servo controller 16 and a magnetic disk 21.

The magnetic disk 21 is composed of one or a plurality of sheets, and the recording surface is single-sided or double-sided (front and back of the disk). A head is disposed on the recording surface. FIG. 1 shows a state in which two magnetic disks 21a and 21b are arranged and two recording / reproducing heads (magnetic heads) 22a and 22b are provided correspondingly.
In other words, several magnetic disks (platters) can be concentrically overlapped in the drive unit. At that time, the same track number of each magnetic disk is arranged in a cylindrical shape (cylinder), and the same cylinder as the track number. It is specified by number.
As shown in FIG. 1, one recording / reproducing head 22 is arranged for one magnetic disk 21 when one side of the magnetic disk 21 is a recording surface.
When both surfaces are recording surfaces, two recording / reproducing heads 22 are arranged for one magnetic disk 21.

In FIG. 1, the CPU 11 executes control codes stored in the ROM / RAM 12 to comprehensively control the operation in the HDD 10.
Also, an access unit setting process described later is performed, and the recording / reproducing operation is controlled based on the access unit setting process.
The disk controller 13 receives a command from a host device connected via the interface 17. In this example, the camera unit 50 is a host device as described above. For example, a command from the camera unit 50 is transferred to the CPU 11, the CPU 11 performs the command processing, and the disk controller 13 instructs a hardware operation on the data read / write control unit 15 and the servo control unit 16 according to the command processing result.
Write data received from the camera unit 50 via the interface 17 and data read from the magnetic disk 21 and passed to the camera unit 50 are temporarily stored in the buffer RAM 14.

  The data read / write control unit 15 performs a code modulation process to create a data pattern to be actually recorded, and writes data to the magnetic disk 21 via the preamplifier 25. Conversely, the read data is taken in from the magnetic disk 21 via the preamplifier 25 and the data is demodulated.

  The servo control unit 16 synchronously drives a voice coil motor (VCM) 23 that moves an arm on which the magnetic heads 22a and 22b are mounted, and a spindle motor (SPM) 24 that rotates the magnetic disk 21, thereby the magnetic heads 22a, Control is performed so that 22b reaches a predetermined range on the target track on the magnetic disk 21. Furthermore, control is performed to seek the head position to a predetermined position from the servo pattern on the disk.

A large number of tracks, which are sections for recording data, are formed concentrically on the magnetic disk 21. For example, the track numbers are 0, 1, 2,... From the outermost periphery of the disk 21 toward the inner periphery. Allocated. Each track is further divided into sectors, and this sector unit is the minimum unit in which data read / write operations can be performed.
The amount of data in the sector is fixed at 512 bytes, for example.
In addition to data, header information, error correction code, and the like are added to the actually recorded sector.

FIG. 1 shows an ECC control information generating unit 26 particularly straddling the CPU 11 and the ROM / RAM 12.
The ECC control information generation unit 26 is a part that generates control information for instructing the parity structure and interleave structure of the error correction code.
The ECC control information generation unit 26 uses, for example, the ROM / RAM 12 as a location for storing a table used for generating control information, and the CPU 11 performs the control thereof to realize the function.
The format to be recorded / reproduced is determined by the control signal from the ECC control information generator 26. The format is, for example, a format in which the number of sectors in a track unit is integrated into an ECC block, and has a C1 parity for performing error correction within the sector and a C2 parity for performing error correction between sectors.
The ECC block has an interleave structure, and the interleave structure is set as described later.

As for the number of sectors per round, a ZBR (Zone Bit Recording) method is adopted in which the number of sectors increases as it goes to the outer track where the circumference becomes longer. That is, the number of sectors per track over the entire circumference of the magnetic disk 21 is not uniform, and the magnetic disk 21 is divided into a plurality of zones in the radial direction, and is set to have the same number of sectors in each zone.
When switching zones, the number of sectors, the spindle motor 24 rotation speed is kept constant, the recording / reproducing clock is made variable, etc., the linear recording density is kept within a predetermined range, and the storage capacity per disk is increased. To be determined.

  FIG. 2 shows the internal configuration of the disk controller 13 of FIG. 1 in more detail. As shown in the figure, the disk controller 13 includes a CPU interface 31, a host controller 32, a buffer controller 33, a servo controller 34, a disk formatter 35, and an ECC controller 36. In the figure, an arrow that causes data movement is indicated by a double line.

The CPU interface 31 is an interface between the CPU 11 and the RAM / ROM 12, and notifies the CPU 11 of a command from a host such as the camera unit 50 or receives a command processing result from the CPU 11.
The host controller 32 communicates with a host (camera unit 50) connected via the interface 17.
The buffer controller 33 controls the exchange of data between the buffer RAM 14 and each unit in the disk controller 13.
The servo controller 34 reads the servo information from the servo pattern on the magnetic disk 21 by controlling the operations of the VCM (voice coil motor) 23 and the SPM (spindle motor) 24, and passes this information to the servo controller 15.
The disk formatter 35 performs control for writing data on the buffer RAM 14 to the magnetic disk 21 or reading data from the magnetic disk 21.
The ECC controller 36 generates and adds an ECC code from the data stored in the buffer RAM 14 at the time of writing, or performs error correction at the time of reading.
The disk controller 13 shown in FIG. 2 receives formatter control information and ECC control information from the CPU 11 (and the ECC control information generating unit 26 formed by the CPU 11 and the ROM / RAM 12).
That is, the disk controller 13 receives the parity information and control information of the interleave structure by the ECC control information generation unit 26 through the CPU interface 31. The formatter control information based on the ECC control information is supplied to the disk formatter 35, and the ECC controller 36 receives information on the ECC format and interleave structure necessary for ECC error correction processing (error correction encoding processing and error correction decoding processing). Are sent respectively.

As an access method, access is performed based on a so-called LBA (Logical Block Address).
In the case of accessing by LBA, the formatter control information is format information for accessing the sector specified by LBA after being accessible on the sought track. This information is sent to the disk formatter 35 via the CPU interface 31, where a data formatter is generated.
Also, the ECC format information in the ECC control information sets the ECC block configuration with the first error correction code C1 or the ECC block configuration with the first error correction code C1 and the second error correction code C2. In addition, for example, when the ECC block configuration is varied according to the number of sectors or the like for each zone, the information is used to instruct the configuration. This information is sent to the ECC controller 36 via the CPU interface 31, where the ECC block configuration is set, and the buffer RAM 14 is accessed to perform predetermined ECC processing.

The control information (formatter control information, ECC control information) is stored in the ROM / RAM associated with the CPU 11 in FIG. 1, and for example, the information is stored in the magnetic disk 21 and activated. Sometimes, data may be read from the magnetic disk 21 and stored in the buffer RAM 14. In this case, control information may be sent from the buffer RAM 14 to each unit.

2. Interleave configuration setting considering error periodicity 2-1 Sector interleave setting

In the HDD 10 of this example, an interleave structure is set for each zone in the disk 21, for example, the number of servo frames is 96, the code length maximum value of the interleave code frame is 255, and an example of normal interleave setting for each zone is as follows: It was previously shown in FIG.
In the normal interleave setting, first, the number of interleaves is set so that the code length of each code frame becomes as large as possible after considering the maximum code length. Each code is arranged so as to be sequentially assigned to each code frame. An example in which such normal interleaving is set as sector interleaving is as shown in FIG.
However, due to the periodicity of error occurrence, when normal interleave setting is performed, error sectors may concentrate on specific code frames as in zones # 4, # 10, and # 13 in FIG.
Therefore, in this example, sector interleaving is set so as to avoid error concentration due to the correlation between the interleave period and the error occurrence period.
In particular, as described with reference to FIG. 15, when an error tends to occur in a specific period such as a servo frame period, a mechanism for eliminating error periodicity as much as possible is incorporated in the interleave configuration.
As a technique to reduce error concentration,
Two methods are conceivable: the number of interleaves is variably set based on the periodicity of the sector error occurrence distribution, and the code frame allocation order for each sector is variably set based on the periodicity of the sector error occurrence distribution.

First, an example of variably setting the number of interleaves is shown in FIG.
In FIG. 3A, normal interleave setting is performed for zones in which error concentration is not assumed, that is, zones # 0 to # 3, # 5 to # 9, # 11, # 12, # 14, and # 15. That is, these zones have the same settings as in FIG.
On the other hand, for zones # 4, # 10, and # 13, if normal interleave setting is performed, error concentration may occur. Therefore, in these zones, the number of interleaves m is set variably.
Therefore, for zone # 4, as shown in the figure, the number of interleaves is m = 4, and interleaving is performed with four code frames i0, i1, i2, and i3. Since the number of sectors per track is 576, the code length of each code frame i0, i1, i2, i3 is 144 sectors.
Then, the sectors t0, t0 + 1,... In the zone # 4 are sequentially assigned to the code frames i0, i1, i2, i3 as shown in FIG. The sectors of the servo frame period are not concentrated on one code frame.

Similarly, for zone # 10, the number of interleavings is m = 3, and interleaving is performed with three code frames i0, i1, and i2. The code length of each code frame i0, i1, i2 is 160 sectors.
For zone # 13, the number of interleavings is m = 3, and interleaving is performed with three code frames i0, i1, and i2. The code length of each code frame i0, i1, i2 is 128 sectors.

By changing the setting of the number of interleaves m in this way, it is possible to avoid error concentration on a specific code frame due to the periodicity of the error occurrence frequency.
For example, by increasing the interleaving number m by 1 in the zones # 4, # 10, and # 13, the error concentration period is increased from 6 sectors to 12 sectors, from 10 sectors to 15 sectors, and from 4 sectors to 12 sectors. Can ease concentration.
Although this method has a demerit that the code length per code frame becomes small, it is effective in avoiding error concentration and exerting the original ECC error correction capability.
In this example, the interleave number m is increased. However, in some cases, the error concentration due to error periodicity may be avoided by reducing the interleave number m.

Next, an example will be described in which the setting of the interleave number m is normal and the code frame allocation order for each sector is variably set based on the periodicity of the sector error occurrence distribution.
As a method for variably setting the code frame allocation order for each sector, it is conceivable to change the code frame number allocation order for each servo frame according to a certain rule, or to randomly set the allocation order.

First, FIG. 4A shows an example in which the allocation order is variably set with a certain regularity. Similarly to the above, zone # 4 is taken as an example. In the normal interleave setting, in zone # 4 where the number of sectors per track is 576, the number of interleaves m = 3. In this case, the number of interleaves m = 3.
When there are 96 servo areas, each servo frame SF includes 6 sectors, but in the first servo frame SF0, as shown in FIG. The code frames i0, i1, and i2 are assigned in this order.
In the next servo frame SF1, six sectors are assigned in the order of code frames i1, i2, and i0.
Further, in the next servo frame SF2, 6 sectors are assigned in the order of the code frames i2, i0, i1.
These three allocation patterns are repeated for each servo frame.

When assigning each sector to the code frame in this way, the code frame i may be calculated by the following calculation from the LBA of each sector.
When the LBA of the head sector of the track is t0, the code frame i is expressed by using the LBA of a certain target sector.
i = ((LBA-t0) + └ (LBA-t0) / SC┘) mod m
Is calculated by In this equation, i means i0 if the value is 0, i1 if the value of i is 1, and so on.
“SC” means the number of sectors in one servo frame SF, “mod” means a remainder, and “└ ┘” means rounding down after the decimal point.
The number of sectors SC in one servo frame SF is
SC = [number of sectors in one track / number of servo frames]
Is calculated by [] In this formula means rounding. In the case of zone # 4, SC = [576 ÷ 96] = 6.

By assigning each sector to the code frame in this way, the sector of the servo frame period is allocated to the three code frames i0, i1, and i2. Therefore, it is possible to avoid error concentration on a specific code frame due to the periodicity of error occurrence frequency (servo frame period).
In this example, the servo frame period error is expanded from 6 sector periods to 18 sector periods. In this zone # 4, since the number of sectors per track is 576, the number of errors concentrated on a specific code frame is greatly reduced from 96 times to 32 times.
As a result of the same countermeasures, in zone # 10, the error concentration period is changed from 10 sectors to 20 sectors, and the number of error concentrations is reduced from 48 times to 24 times. In zone # 13, the error concentration period is changed from 4 sectors to 8 sectors, so that the number of error concentrations is reduced from 96 to 48.

Compared to the case where the number of interleaves m is varied, this method has the advantage that the number of sectors per code frame set to maximize the code length is not changed. However, there is a case where code distribution for each code frame is insufficient for an error that continues in a plurality of sectors such as a burst error.
When the rate of occurrence of burst errors is low and code dispersion for each code frame with respect to burst errors is relatively not required, the interleaving number m as shown in FIG. 4B is set so that the code length is maximized, A method of performing code arrangement for each code frame at random for each sector in the error period is effective.

FIG. 4B shows an example in which the interleave number m is “3” as usual for zone # 4 and each sector is randomly assigned to a code frame.
In the case of the example in this figure, in the first servo frame SF0, six sectors are assigned to the code frames i2, i0, i1, i1, i2, i0.
In the next servo frame SF1, six sectors are allocated to code frames i1, i2, i2, i0, i1, i0.
Further, in the next servo frame SF2, six sectors are assigned to the code frames i0, i2, i1, i2, i1, i0.
The subsequent servo frames are assigned in a random order.

As described above, by randomly assigning each sector to the code frame in units of servo frames, the sector of the servo frame period is allocated to the three code frames i0, i1, and i2. Therefore, it is possible to avoid error concentration on a specific code frame due to the periodicity of error occurrence frequency (servo frame period).
The term “random” is used here, but it is not a complete random order, and the code length of each code frame must be finally derived from the interleave number m and the sector number. There is. For example, in the example of FIG. 4B, there are 6 sectors in the servo frame and the number of interleaves m = 3, but 2 sectors are included in the code frames i0, i1, i2 in each servo frame unit. By assigning, the code length of each code frame i0, i1, i2 can be set to 144 sectors.
However, conversely, if the code length of each code frame i0, i1, i2 is 144 sectors as a result, it is not always necessary to allocate 2 sectors to each code frame in servo frame units.

In addition, when distributing randomly, processing at the time of deinterleaving must also be considered. That is, if the allocation order is not known at the time of interleaving, the sector order cannot be restored correctly.
For this reason, when numerical values 0, 1, and 2 are randomly generated for each sector and assigned to the numerical values of the code frames i0, i1, and i2, it is necessary to store the code frame numbers in the random order. For example, it is necessary to store this random number sequence in a predetermined area in the ROM / RAM 12 or the magnetic disk 21 so that it can be referred to during deinterleaving.
In that sense, a fixed pattern may be set in advance as a random pattern. On each combination as the relationship between the number of interleaves m and the number of sectors in the servo frame, a random number sequence is set in units of several servo frames or tracks, for example, in the ROM / RAM 12 or the magnetic disk 21. It is stored in a predetermined area. At the time of interleaving, a method of assigning each sector to each code frame using a random pattern corresponding to the combination can be considered. In that case, deinterleaving can be correctly performed by referring to the random pattern corresponding to the combination even during deinterleaving.

In addition, as a method for reducing the error concentration, the interleave number is variably set based on the periodicity of the sector error occurrence distribution, and the code frame allocation order for each sector is variably set. You may combine these two.
In other words, it is also conceivable to variably set the code frame allocation order for each sector while setting the interleave number m to be different from the usual setting.

2-2 Interleave setting of byte data in a sector

Next, interleave setting for byte data in a sector will be described.
As shown in FIG. 17A, when there is a bias in the error frequency for the logical byte position in the sector, error correction in units of one sector shown in FIG. Since error correction is performed on byte data, error concentration may occur.
Therefore, in this example, errors are distributed to the logical byte positions in the sector by one of the following methods.
-Change the byte data arrangement for each sector-Divide the ECC code in the sector into multiple blocks and arrange it so that errors are distributed

First, FIG. 5 shows an example of changing the arrangement of byte data for each sector.
For example, in the error frequency shown in FIG. 17A, when the range of several tens of sectors from the head of the byte position in the sector is excluded, the error frequency tends to decrease from the head of the sector to the end.
Here, as shown in the ECC configuration of FIG. 17B, when byte positions are normally arranged from 0 to 511 in each sector and error correction is performed in byte units along the byte positions in the sector, the error distribution in the sector is obtained. The error concentrates on a specific byte position with the bias.
Therefore, as shown in FIG. 5, an ECC configuration in which the reverse order of the byte arrangement is combined is used. That is, the ECC configuration is such that sectors with byte position order 0 to 511 and sectors with byte position order 511 to 0 are alternately arranged.
In this way, the ratio of errors to the code length n can be averaged, and error concentration based on the error frequency distribution can be avoided.

Next, an example in which the ECC code in the sector is divided into a plurality of blocks and the error is distributed will be described with reference to FIGS.
This is an interleave configuration in which intra-sector data is divided into a plurality of blocks in consideration of error frequency, and the blocks are rearranged.
As shown in FIG. 6A, in consideration of the fact that the error frequency in the sector has many errors at the byte position of 23% from the head and less at the byte position of 30% from the tail, blocks a to d in the sector. Is divided into four equal parts, and an interleaved arrangement that combines places with many errors and places with few errors is performed.
Assuming that one sector = 512 bytes, block a is bytes 0 to 127, block b is bytes 128 to 255, block c is bytes 256 to 383, and block d is bytes 384 to 511.

For example, FIG. 6B shows a state in which each sector SC (SC # 1, SC # 2,...) Is divided into four blocks a, b, c, and d. For example, sector SC # 1 is divided into blocks # 1a to # 1d, and sector SC # 2 is divided into blocks # 2a to # 2d.
Then, as shown in FIG. 6C, sectors arranged in the order of blocks a, b, c, and d and sectors arranged in the order of blocks b, c, b, a are alternately arranged. That is, sector SC # 1 is arranged as blocks # 1a, # 1b, # 1c, # 1d, sector SC # 2 is arranged as blocks # 2d, # 2c, # 2b, # 2a, and sector SC # 3 is arranged as block #. Arrange 3a, # 3b, # 3c, # 3d and so on.
FIG. 7 shows the ECC configuration according to the arrangement of FIG. 6C in byte units.
Then, as can be seen from FIG. 7, sectors arranged in the order of bytes 0-127, 128-255, 256-383, 384-511, and bytes 384-511, 256-383, 128-255, 0-127. This is an ECC structure in which the sectors arranged in this order are alternately arranged in the vertical direction.
By adopting such an ECC structure, a section with a lot of errors and a section with few errors in a sector are combined, so that error concentration can be avoided and the ratio of code length to errors can be reduced.

3. Example of interleave configuration setting process 3-1 Sector interleave setting process

In this example, as described above, sector interleave setting or interleave setting of intra-sector byte arrangement is performed. Processing of the CPU 11 (ECC control information generating unit 26) for realizing these will be described.

First, referring to FIG. 8, a code word arrangement setting process for performing the interleave setting as shown in FIG. 3 or 4 will be described as sector interleave setting.
In step F101, the variable x is set to 0, and after step F102, the process for zone #x, that is, zone # 0 is first performed.
First, in step F102, data recording / reproduction is performed in zone # 0, and the sector error position is measured for each track. The measurement may be performed for all tracks in the zone # (x), or a predetermined number of tracks in a partial section in the zone may be a measurement target.
In step F103, whether or not there is a possibility of error concentration in a specific code frame from the relationship between the error periodicity obtained from the sector error measurement result and the number of interleaves m in the normal interleave setting for that zone. Judging.
Specifically, for example, the data length is the period that is the least common multiple of the interleave code arrangement period (interleave number m) and the period (for example, servo frame period) at the relative position in the track of the sector error measured in step F102. If it is smaller than (the number of sectors), it is determined that there is a possibility of error concentration in a specific code frame.

  When it is determined that there is no possibility of error concentration, the process proceeds to step F104, and normal interleave setting is performed for the zone. That is, as described above, in consideration of the maximum code length, the number of interleaves is set so that the code length of each code frame is as large as possible, and each codeword (in this case, sector) is sequentially assigned to each code frame. It arranges so that it may be assigned to.

On the other hand, if it is determined in step F103 that there is a possibility of error concentration, the process proceeds to step F105, and the position of the code word considering the error periodicity is set for the zone.
That is, if the example of FIG. 3 is adopted, the interleaving number m is set to a value different from the normal setting. If the example described with reference to FIG. 4 is employed, the code frame allocation order for each sector is variably set.

In step F106, the value of the variable x is confirmed. If x is not the final zone number, the variable x is incremented in step F107 and the process returns to step F102. The same processing is performed for the next zone.
That is, the processes of steps F102 and F103 are performed for each zone, and the interleave setting is performed in step F104 or F105. In step F106, it is confirmed that the processing from the value of the variable x to the final zone has been completed, and the code word arrangement setting processing is completed.

  For example, if the process of changing the number of interleaves m is performed in step F105, the interleave setting shown in FIG. 3A is performed. That is, for zone # 4, # 10, and # 13, a different interleave number m is set in step F105, and in other zones, a normal interleave number m is set in step F104.

The processing of FIG. 8 is performed in the initial setting before factory shipment in the HDD 10, and the interleave setting information by this processing may be stored in a non-volatile area of the ROM / RAM 12 or a specific area in the magnetic disk 21. .
Further, it may be performed at the time of initial setting or formatting at the user side after shipment.
In the measurement in step F102, the error occurrence period may be estimated from the number of servo frames without actually detecting the error sector.

The interleave setting made in this way is used for ECC processing during recording and reproduction.
The flow of ECC processing during recording / reproduction will be described with reference to FIG.
FIG. 9 shows processing realized by the operation of each unit in FIG. 1 centering on the CPU 11 and the disk controller 13 at the time of data writing or reading.
First, when a write target track is set in step F201, a zone including the track is determined in step F202.
Next, in step F203, the interleave setting information set in the above-described processing of FIG. 8 and stored in the ROM / RAM 12 is referred to, and in step F204, the interleave setting (code word arrangement setting) in the zone is read.
In step F205, the CPU 11 (ECC control information generation unit 26) sends the read ECC control information including the interleave setting and the parity setting to the disk controller 13, and the ECC controller 36 receives the data of the track to be recorded / reproduced. The ECC format to be processed is determined. Then, the process proceeds to the writing or reading process.
When writing, the ECC controller 36 generates an ECC block according to the instructed parity sector number and interleave setting. Then, the process proceeds to the writing process.
When reading, the ECC controller 36 determines the ECC block format according to the instructed parity sector number and interleave setting. Thereafter, error correction processing and deinterleaving are performed on the data read from the corresponding track in the ECC block format.

3-2 Interleave setting process for byte data in a sector

Next, interleave setting processing for byte data in a sector will be described with reference to FIG.
The processing of FIG. 10 may be performed at the time of other formatting before factory collection, at the time of initial setting, etc. as in FIG.
First, in step F301, the CPU 11 sets a plurality of sector ranges to be measured, and measures byte errors for the plurality of sectors.
That is, data recording / reproduction is performed in a plurality of sectors to be measured, and the byte error position is measured for each sector.
In step F302, it is determined from the measurement result whether the byte error distribution in the sector has periodicity. That is, it is determined whether or not many errors have been detected in a specific byte position, byte position range, or the like.

If there is no periodicity in the byte error distribution in the sector, normal intra-sector codeword arrangement is set in step F303. That is, the code word arrangement is set as shown in FIG.
On the other hand, if the byte error distribution in the sector has periodicity, in order to avoid the occurrence of error concentration due to this, in step F304, intra-sector codeword arrangement is set in consideration of error periodicity. That is, the code word arrangement is set as shown in FIG.
By setting the code word arrangement of the byte data in the sector in this way, it is possible to avoid error concentration due to error periodicity. Of course, at the time of recording / reproducing, the byte arrangement setting shown in FIG. 10 is included in the ECC control information and transferred to the ECC controller 36, so that errors can be prevented from being concentrated in the error correction direction in the byte data arrangement in the sector. Is.

Since the setting shown in FIG. 10 is an arrangement setting of byte data in the sector, it can be executed together with the sector interleave setting shown in FIG.
That is, as an example of processing at the mounting level in the HDD 10, only the sector interleave setting in FIG. 8 is performed, the interleave setting of the byte data in the sector in FIG. 10 is performed, and the sector interleave setting and the interleave setting of the byte data in the sector are performed. An example in which both are performed can be considered.

As described above, the HDD 10 of this example can perform ECC setting in consideration of error periodicity, and can average the number of errors in ECC units (code frames) and push down the maximum value. As a result, the original error correction capability can be exhibited. In addition, this allows a large margin for errors. Then, the number of ECC parities can be reduced, and the data area can be increased. In other words, the data capacity can be increased, the transfer rate can be improved, and the data density can be increased.

4). Modified example

Hereinafter, various modifications and application examples will be described.
In the above embodiment, the recording / reproduction control device and the recording / reproduction control method of the present invention are realized by the control unit (CPU 11 or disk controller 13) in the HDD 10. As another example, an HDD control device 60 shown in FIG. 11 may be provided as a device separate from the HDD, and the HDD control device 60 may be considered as the recording / reproduction control device of the present invention.
In the case of the system shown in FIG. 11, for example, an HDD control device 60 is connected between the camera unit 50 serving as a host device and the HDD 10A. In this case, it is assumed that the HDD 10A is a conventional normal HDD and does not have the above-described interleave setting function.

The HDD control device 60 includes a CPU 61, an ATA interface 63, an external interface 64, a memory controller 66, and a buffer RAM 67, and data / command / control information is transferred between the CPU bus 62 and the data bus 65. Has been.
The external interface 64 exchanges commands and recording / reproduction data with the camera unit 50. The ATA interface 63 exchanges commands and recording / reproduction data with the HDD 10A.
Data transferred from the camera unit 50 to the external interface 64 for recording in the HDD 10A is temporarily stored in the buffer RAM 67 under the control of the memory controller 66, read at a predetermined timing, and supplied from the ATA interface 63 to the HDD 10A. The
The data reproduced by the HDD 10A and transferred to the ATA interface 63 is temporarily stored in the buffer RAM 67 under the control of the memory controller 66, read at a predetermined timing, and supplied from the external interface 64 to the camera unit 50.

In this case, when the system is connected, the CPU 61 performs the above-described code word arrangement setting process of FIGS. 8 and 10 while controlling the HDD 10A.
That is, the CPU 61 issues a command to the HDD 10A to execute a recording / reproducing operation for measuring a sector error or an intra-sector byte error, and performs codeword arrangement setting based on the measurement result.
Thereafter, when a recording request is issued from the camera unit 50, the AV stream data transferred from the camera unit 50 is read from the buffer RAM 67 for each predetermined access unit size while being accumulated in the buffer RAM 67 and transferred to the HDD 10A. To go. When data of each access unit size is transferred to the HDD 10A, a write instruction is given by designating the write destination LBA, interleave setting according to the write destination zone, and byte arrangement in the sector Is transferred to the HDD 10A. The HDD 10A performs ECC processing based on the passed interleave setting.
Also, when receiving a data reproduction instruction from the camera unit 50, the HDD 10A is instructed to start reading, and the reproduction is executed. Also at this time, the interleave setting corresponding to the read position is notified so that appropriate deinterleaving is performed.

The HDD control device 60 that performs such processing can also obtain the same effects as those described in the above embodiment.
In addition, by providing the HDD control device 60 separate from the HDD in this way, it is possible to improve the error correction capability in the conventional HDD, and improve the recording / reproducing performance of the conventional HDD. it can.
Further, when the HDD control device 60 is provided in this way, interleaving / deinterleaving may be performed in the HDD control device 60 according to the interleave setting.
That is, at the time of recording, the interleaved data is transferred to the HDD 10A in the HDD control device 60. Further, at the time of reproduction, a process of deinterleaving the data transferred from the HDD 10A by the HDD control device 60 and transferring the data to the camera unit 50 is also conceivable.
Further, the function as the HDD control device 60 may be incorporated in a host device such as the camera unit 50.

The present invention is not limited to the HDD, and the present invention can be applied to other types of disc recording / reproducing apparatuses. For example, the present invention can be applied to a system in which a track has a spiral shape in addition to a concentric track shape. Of course, the present invention can be applied not only to magnetic disks but also to systems for optical disks and magneto-optical disks.
In general, in the HDD, the disk 21 is fixedly incorporated in the apparatus, but an HDD in which the disk 21 is removable is also conceivable. The present invention can be applied to such an apparatus.

  In the present invention, a program for causing the CPU 11 or the like to perform interleave setting can be stored in advance in the ROM / RAM 12, for example. Alternatively, a form in which the data is stored in the magnetic disk 21 and loaded into the ROM / RAM 12 is also conceivable.

It is a block diagram of the whole structure of HDD of embodiment of this invention. It is a block diagram of a disk controller of the HDD of the embodiment. It is explanatory drawing of the number setting of the interleaving according to the error periodicity of embodiment. It is explanatory drawing of the variable setting of the allocation of the code frame for every sector of embodiment. It is explanatory drawing of the interleave setting of the byte data in a sector of embodiment. It is explanatory drawing when the byte data in a sector of an embodiment is made into a block, and the allocation is variably set. It is explanatory drawing of the block allocation of the interleave setting of embodiment. It is a flowchart of the code word arrangement | positioning setting process of embodiment. It is a flowchart of the process at the time of the recording / reproducing of embodiment. It is a flowchart of the code word arrangement | positioning setting process in the sector of embodiment. It is a block diagram of the HDD control apparatus of other embodiment. It is explanatory drawing of the zone of a disk. It is explanatory drawing of the servo area of a disk. It is explanatory drawing of a normal interleave setting. It is explanatory drawing of the periodicity of error occurrence frequency. It is explanatory drawing of the error concentration in normal interleave setting. It is explanatory drawing of the error occurrence frequency of the data in a sector.

Explanation of symbols

  10 HDD (Hard Disk Device), 11, 61 CPU, 12 ROM / RAM, 13 Disk Controller, 14, 67 Buffer RAM, 15 Data Read / Write Control Unit, 16 Servo Control Unit, 21 Magnetic Disk 22, 22a, 22b Magnetic Head, 26 ECC control information generator, 31 CPU interface, 35 disk formatter, 36 ECC controller

Claims (16)

In the data recording area of the recording medium, a determination step for determining the periodicity of the error occurrence distribution,
A setting step for setting an interleave configuration of data to be recorded / reproduced with respect to the recording medium based on the periodicity of the error occurrence distribution obtained in the determination step;
A recording / reproduction control step for controlling to execute an error correction process using the interleave configuration set in the setting step when recording / reproducing data on the recording medium;
And a recording / reproducing control method. The recording medium is a disk recording medium in which concentric or spiral tracks are formed and a plurality of zones are set in the radial direction.
In the determination step, the periodicity of the error occurrence distribution is determined for each zone,
2. The recording / reproducing control method according to claim 1, wherein, in the setting step, an interleave configuration is set for each zone based on the periodicity of the error occurrence distribution determined for each zone. The recording medium is a disk recording medium in which concentric or spiral tracks are formed and each track is divided into a plurality of sectors.
In the determination step, the periodicity of the distribution of occurrence of sector errors in the track is determined,
2. The recording / reproducing control method according to claim 1, wherein in the setting step, a sector interleaving configuration is set based on a periodicity of a sector error occurrence distribution.   4. The recording / reproducing control method according to claim 3, wherein, in the setting step, the number of interleaves is variably set based on the periodicity of the sector error occurrence distribution.   4. The recording / reproducing control method according to claim 3, wherein in the setting step, the allocation order of the interleave code frames for each sector is variably set based on the periodicity of the sector error occurrence distribution. The recording medium is a disk recording medium in which concentric or spiral tracks are formed and each track is divided into a plurality of sectors.
In the determination step, the periodicity of the occurrence distribution of byte errors in the sector is determined,
2. The recording / reproducing control method according to claim 1, wherein, in the setting step, an interleave configuration in the sector is set based on the periodicity of the byte error occurrence distribution.   7. The recording / reproducing control method according to claim 6, wherein in the setting step, the byte data arrangement order for each sector is variably set based on the periodicity of the byte error occurrence distribution.   7. The setting step includes dividing the byte data in the sector into a plurality of blocks and variably setting the arrangement order of the blocks for each sector based on the periodicity of the byte error occurrence distribution. The recording / reproducing control method described. A discriminating means for discriminating the periodicity of the error occurrence distribution in the data recording area of the recording medium;
Setting means for setting an interleave configuration of data to be recorded / reproduced with respect to the recording medium based on the periodicity of the error occurrence distribution grasped by the determining means;
A recording / reproduction control unit that controls to execute an error correction process using the interleave configuration set by the setting unit when recording / reproducing data on the recording medium;
A recording / reproducing control apparatus comprising: The recording medium is a disk recording medium in which concentric or spiral tracks are formed and a plurality of zones are set in the radial direction.
The determining means determines the periodicity of the error occurrence distribution for each of the zones,
10. The recording / reproducing control apparatus according to claim 9, wherein the setting unit sets an interleave configuration for each zone based on the periodicity of the error occurrence distribution determined for each zone. The recording medium is a disk recording medium in which concentric or spiral tracks are formed and each track is divided into a plurality of sectors.
The determining means determines the periodicity of the occurrence distribution of sector errors in the track,
10. The recording / reproducing control apparatus according to claim 9, wherein the setting means sets an interleave configuration of sectors based on a periodicity of sector error occurrence distribution.   12. The recording / reproducing control apparatus according to claim 11, wherein the setting means variably sets the number of interleaves based on the periodicity of the sector error occurrence distribution.   12. The recording / reproducing control apparatus according to claim 11, wherein the setting means variably sets the allocation order of interleave code frames for each sector based on the periodicity of the sector error occurrence distribution. The recording medium is a disk recording medium in which concentric or spiral tracks are formed and each track is divided into a plurality of sectors.
The discrimination means discriminates the periodicity of the occurrence distribution of byte errors in the sector,
10. The recording / reproducing control apparatus according to claim 9, wherein the setting means sets an interleave configuration in a sector based on a periodicity of a byte error occurrence distribution.   15. The recording / reproducing control apparatus according to claim 14, wherein the setting means variably sets the byte data arrangement order for each sector based on the periodicity of the byte error occurrence distribution.   15. The setting unit according to claim 14, wherein the setting means divides the byte data in the sector into a plurality of blocks and variably sets the arrangement order of the blocks for each sector based on the periodicity of the distribution of byte error occurrence. The recording / reproducing control apparatus described.

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