JPH103752A - Data recording and reproducing device and deciding method for sector to be substituted in the device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decide a sector to be substituted in which an executing time in access for a sector already substitution-processed is made the minimum. SOLUTION: When a sector to be substituted for a defective sector on a disk 1 is decided, a CPU 10 discriminates whether remainder obtd, by dividing a seek time required for seeking a spare track head 2 on the disk 1 from a track in which this defective sector exists by one rotation time of the disk 1 is less than 1/2 rotation time or not. When the remainder is less than 1/2 rotation time, a spare sector placed at a physical position on an opposed side to a physical position of the defective sector with respect to the center of the disk 1 is decided as a sector to be substituted for the defective sector among the spare tracks, when the remainder is more than 1/2 rotation time, a spare sector placed at a physical position on the same side with a physical position of the defective sector with respect to the center of the disk 1 is decided as a sector to be substituted for the defective sector among the spare tracks.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a data recording / reproducing apparatus suitable for selectively allocating a replacement destination sector of a defective sector from spare tracks and a method of determining a replacement destination sector in the apparatus.

[0002]

2. Description of the Related Art In a data recording / reproducing apparatus typified by a magnetic disk apparatus which performs data recording / reproducing with a head, sectors which are difficult to read / write correctly due to defects on a recording medium (media, disk) have occurred. In this case, use of the sector as a defective sector is stopped, and an alternative destination sector is determined and assigned from spare tracks (alternate destination tracks) prepared for relocation (alternative) of the defective sector in advance. Generally, an alternative process is performed.

Conventionally, a method of determining a replacement destination sector in this replacement process is to allocate the defective sector in order from the first physical sector on the spare track, regardless of the physical sector number (physical position on the disk) of the defective sector. Was.

[0004] When accessing a continuous sector group including a sector on which the above-described replacement processing has been performed, a spare track is sought to access a replacement destination sector.
Then, since it is necessary to seek to the original track, (seek time to the spare track + rotation waiting time to the alternative destination sector + seek time to the original track + next time) The execution time is increased by the rotation waiting time up to the sector of ()). Here, the rotation waiting time up to the replacement destination sector and the rotation waiting time up to the next sector are both one rotation time (of the disk) at maximum.

[0005]

As described above, the access (read / write access) to the sector on which the replacement process has been performed is compared with the case of accessing the normal sector (the seek to the spare track). Execution time is increased by (time + rotation waiting time to alternative destination sector + seek time to original track + rotation waiting time to next sector). Moreover, in the above-described conventional technology, the replacement destination sector is determined irrespective of the physical sector number of the defective sector, and there is no regulation on the positional relationship between the physical location of the defective sector and the physical location of the replacement destination sector. Therefore, both the rotation waiting time to the replacement destination sector and the rotation waiting time to the next sector become one rotation time (of the disk) at the maximum, and there is a problem that the execution time is greatly increased in some cases.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a replacement process for assigning a replacement destination sector to a defective sector, from the physical position of the defective sector to the spare track to the spare track. Considering the time required for seeking, determine the replacement destination sector that minimizes the execution time in accessing the sector where the replacement processing was performed, thereby minimizing the performance degradation due to the replacement processing It is an object of the present invention to provide a data recording / reproducing apparatus capable of suppressing the number of sectors and a method of determining an alternative destination sector in the apparatus.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a data recording / reproducing apparatus provided with a disk in which a spare track including a plurality of spare sectors for relocating defective sectors is secured.
An alternative destination sector determining means for determining a spare sector (alternative destination sector) as a replacement destination of a defective sector from among the spare tracks is provided, and a seek time required to seek from the track where the defective sector exists to the spare track is provided. Based on a value determined by one rotation time of the disk, for example, a remainder obtained by dividing a seek time by one rotation time of the disk, a spare sector at a physical position opposite to the physical position of the defective sector with respect to the center of the disk. , Or one of the spare sectors located at the same physical position as that of the defective sector with respect to the center of the disk is determined as the replacement destination sector of the defective sector.

Here, １ ／ of one rotation time of the disk is introduced as a reference value of the remainder for determining the replacement destination sector of the defective sector, and the replacement destination sector determining means determines that the remainder is 回 転 rotation. If it is less than the time, the spare sector at the physical position opposite to the physical position of the defective sector with respect to the center of the disk is less than 1/2 rotation time, and the physical size of the defective sector with respect to the center of the disk is more than 1/2 rotation time. The spare sector located at the same physical position as the target position may be determined as the replacement destination sector. Therefore, it is preferable to provide a determination means for determining whether or not the remainder is less than 1/2 rotation time. It should be noted that whether the remainder, that is, the remainder obtained by dividing the seek time required for seeking from a track having a defective sector to a spare track by one rotation time of the disk, is less than 1/2 rotation time of the disk. The determination is to determine whether or not the fractional part of the divided value is less than 更 に. Further, the relative displacement angle of a predetermined position (for example, a defective sector) on the disk during the seek is determined. This is equivalent to determining whether the ratio with respect to 360 degrees is less than 1/2. Therefore, in the present invention, determining a replacement destination sector based on a remainder obtained by dividing a seek time required for seeking from a track having a defective sector to a spare track by one rotation time of the disk requires that the defective sector be determined. Determining an alternative destination sector based on a fractional part of a value obtained by dividing a seek time required to seek from an existing track to a spare track by one rotation time of a disk; It is assumed that the alternative sector is determined based on a ratio of a relative displacement angle of a predetermined position on the disk to 360 degrees during the seek operation.

Here, in the case of a disk to which the CDR format is applied, the sector number of the defective sector is i, and the zone to which the track in which the defective sector exists is Z.
n, the number of data sectors in the zone Zn is N, the zone to which the spare track belongs is Zm, and the number of data sectors in the zone Zm is M, the physical location opposite to the physical location of the defective sector with respect to the center of the disk. The sector number f of the spare sector at the position is calculated by calculating the integer part of f = {(i / N) * M + (M / 2)}. The sector number f of the spare sector at the target position may be obtained by calculating the integer part of f = {(i / N) * M}.

In addition, if the spare sector determined as the replacement destination sector has already been used as a replacement destination sector for another defective sector, the replacement destination sector is determined again, and the spare sector is determined as the replacement destination sector among the unused spare sectors. The spare sector located closest to the spare sector thus determined may be newly determined as the replacement destination sector.

In such a configuration, the replacement destination sector of the defective sector is determined in consideration of the physical position of the defective sector and the time (seek time) required for seeking from the track where the defective sector exists to the spare track. Therefore, it is possible to determine an alternative destination sector that can minimize the execution time in accessing the sector that has been subjected to the alternative processing.

In particular, when the remainder obtained by dividing the above-mentioned seek time by one rotation time of the disk is less than 1/2 rotation time, the physical position opposite to the physical position of the defective sector with respect to the center of the disk is determined. A spare sector is replaced as a replacement destination sector for a defective sector, and when the remainder is equal to or longer than 1/2 rotation time, a spare sector located at the same physical position as the physical position of the defective sector with respect to the center of the disk is used. If replacement processing is performed as a replacement destination sector for a defective sector, an increase in execution time when access to a continuous sector group including the replacement-processed sector occurs can be minimized as described below. Becomes

First, in the case of accessing a sector group including a sector that has been subjected to replacement processing, if the sector immediately preceding the sector that has been subjected to replacement processing (defective sector) is accessed, the replacement destination sector of this sector that has been subjected to replacement processing (defective sector) is accessed. To access the spare track from there. If the seek time here is less than, for example, half the rotation time of the disk (in this case, the remainder is less than half the rotation time), the center of the disk is defective. Since the replacement destination is assigned to the spare sector at the physical position (on the spare track) opposite to the physical position of the sector, the seek is completed before the replacement destination sector passes the head, and the replacement destination sector is Can be accessed without waiting for the rotation of the disk.

When the replacement destination sector is accessed, the next sector, that is, one of the replacement-processed sectors (defective sectors) is accessed.
In order to access the next sector, a seek is performed from there to the track having the original replacement-processed sector (defective sector). Since the seek time here is less than one half of one rotation time of the disk, the seek is completed before the next sector of the alternative-processed sector passes the head 2, and the next sector is waited for rotation. Accessible without.

As described above, if the time required for seeking between the track having the replacement-processed sector (defective sector) and the spare track is less than half the rotation time of the disk, the replacement-processed sector (defective sector) is used. As compared with the case of accessing a group of sectors having no defective sector), only the execution time of one rotation time of the disk needs to be increased.

Next, an alternative processed sector (defective sector)
The time required for seeking between a track having a track and a spare track is, for example, 倍 times or more of one rotation time of the disk and 1
If it is less than twice (at this time, the remainder is equal to or longer than 1/2 rotation time), it is at the same physical position (on the spare track) as the physical position of the defective sector with respect to the center of the disk. Since the replacement destination is assigned to the spare sector, if a seek is made to the spare track to access the replacement destination sector after accessing the sector immediately before the replacement-processed sector (defective sector), the replacement destination sector becomes the head. The seek is completed before passing through, and the replacement destination sector can be accessed without waiting for the rotation of the disk. Also, if you seek to the original track to access the next sector after accessing the alternative destination sector,
The seek is completed before the next sector passes through the head, and the next sector can be accessed without waiting for the rotation of the disk.

As described above, the time required for seeking between the track having the replacement-processed sector (defective sector) and the spare track is １ ／ or more of one rotation time of the disk and 1 or more.
If less than twice, the replacement processed sector (defective sector)
It is only necessary to increase the execution time for two rotation times of the disk as compared with the case of accessing a sector group without any data.

From this, when arranging one or a plurality of spare tracks on a disk, a half of the disk is moved from all the tracks (tracks in the data area) on the disk to the spare track closest to the track. If you want to be able to seek within the rotation time,
It is possible to access the replacement-processed sector (including a continuous sector group) most efficiently.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a magnetic disk drive will be described below with reference to the drawings.
FIG. 1 is a block diagram showing a configuration of a magnetic disk drive according to one embodiment of the present invention.

In FIG. 1, 1 is a disk (magnetic disk) as a medium on which data is recorded, and 2 is a head used for writing data to the disk 1 (data recording) and reading data from the disk 1 (data reproduction). (Magnetic head). The head 2 is provided corresponding to each data surface of the disk 1.

As shown in FIG. 2, a large number of concentric tracks are formed on both surfaces of the disk 1, and each track is divided into a plurality of sectors (servo sectors) 101.
Each servo sector 101 includes a servo area 102 in which servo data used for positioning control and the like (including cylinder data indicating a cylinder number and burst data for indicating a position error in a cylinder indicated by the cylinder data by a waveform amplitude) is recorded. And a user area 103 in which data (user data) is recorded. Each servo area 102
On the disk 1, they are arranged radially across the tracks from the center. In each user area 103, a plurality of data sectors are set.

In this embodiment, the disc 1 has a CDR
(Constant Density Recording) method (format). In the CDR system, as shown in the schematic diagram of FIG. 2, the disk 1 is divided into a plurality of zones (here, three zones Z0 to Z2) in the radial direction, and each zone has several tens to several hundred tracks. (Cylinder). In the CDR system, a data sector configuration in which the physical circumference of a cylinder is assumed and the recording density with respect to the circumference is substantially constant, that is, the number of data sectors differs depending on each zone.

A track at a predetermined cylinder position on each surface of the disk 1, for example, an innermost track, is allocated as a spare track 104 for replacing a defective sector. A system area (not shown) is allocated to an area different from the data area on each surface of the disk 1, for example, an area inside the spare track 104. In this system area, the spare track use status table 111 shown in FIG. 3 and the alternative destination allocation status table 1 shown in FIG.
12 are stored.

Spare truck use status table 111
Indicates, for each spare track 104 on each surface of the disk 1, whether or not each sector (spare sector) in the track 104 is assigned as a replacement destination sector for a defective sector. On the other hand, the alternative destination allocation status table 112
Are the position information (head number, cylinder number, and sector number) of the defective sector, the position information (head number, cylinder number, and sector number) of the spare sector in the spare track 104 assigned as a replacement destination of the defective sector. Is shown. At the time of read / write access, by referring to the alternative destination allocation status table 112, since the target sector is a defective sector, it seeks the alternative destination sector (to the spare track 104 where the existing sector is located), and It can be determined whether or not access is required.

In this embodiment, the tables 111, 111
Although 112 is stored in the system area of each surface of the disk 1 for backup, it may be stored only in the system area of a specific surface.
However, from the viewpoint of reliability, it is preferable that the tables 111 and 112 be backed up.

Referring again to FIG. 1, the disk 1 is rotated at a high speed by the spindle motor (SPM) 3. The head 2 is attached to a head moving mechanism called a carriage 4, and moves in the radial direction of the disk 1 by the movement of the carriage 4. The carriage 4 is driven by a voice coil motor (VCM) 5.

The spindle motor (SPM) 3 and the voice coil motor (VCM) 5 are connected to a motor driver 6. The motor driver 6 is a spindle motor 3
The motor 3 is driven by supplying a control current to the voice coil motor 5, and the motor 5 is driven by supplying a control current to the voice coil motor 5. The value of the control current (control amount) is determined by calculation processing of the CPU (microprocessor) 10, and is given, for example, as a digital value.

Each head 2 is connected to a head IC 7 mounted on, for example, a flexible printed wiring board (FPC). The head IC 7 controls switching of the head 2 and inputs and outputs read / write signals to and from the head 2, and has a head amplifier 71 that amplifies an analog output read by the head 2.

The head IC 7 is connected to a read / write IC (read / write circuit) 8. The read / write IC 8 roughly has an encode / decode function for processing user data and a signal processing function for processing servo data.

The read / write IC 8 receives an analog output (read signal of the head 2) read from the disk 1 by the head 2 and amplified by the head amplifier 71 in the head IC 7, and receives a signal necessary for a data reproducing operation. Processing, for example, signal processing for converting analog output into NRZ data and transferring the data to the disk controller (HDC) 14 is performed by a decoding function. Read / write IC8
Is a signal processing required for the data recording operation, for example, HDC1
4 modulates the NRZ data (write data) sent from disc 4 and writes it to the disc 1 (eg, 2-7, 1
-7 modulated data) and sends the signal to the head IC 7 by the encoding function.

The read / write IC 8 executes, by a signal processing function, a servo data reproduction process necessary for servo processing such as head positioning control, in addition to the above-described normal user data recording / reproduction process. That is, read / write I
C8 is the servo area 102 read by the head 2.
And outputs a data pulse including cylinder data to the servo processing circuit 9. Further, the read / write IC 8 samples and holds the peak value of the burst data (in the servo data) and outputs it to the servo processing circuit 9.

The servo processing circuit 9 includes a read / write IC
In response to the data pulse and the burst data from the control unit 8, signal processing necessary for servo processing is executed. That is, the servo processing circuit 9 has a decoding function for extracting and decoding cylinder data (cylinder number) and the like from the data pulse from the read / write IC 8, and a timing generation function such as a write gate. Also, the servo processing circuit 9 has a read / write I
A / D (analog / digital) conversion of the sample / hold result of the peak value of the burst data from C8 to CP
It also has an A / D conversion function to output to U10. The servo processing circuit 9 is configured using, for example, a gate array (GA).

The CPU 10 is, for example, a one-chip microprocessor. The CPU 10 controls each unit in the magnetic disk device according to a control program (firmware) stored in the ROM 11.

The CPU 10 constitutes a servo processing system (head positioning control mechanism) for executing head positioning control together with the servo processing circuit 9, and converts cylinder data extracted by the servo processing circuit 9 and converted by the servo processing circuit 9. The A / D conversion value corresponding to the sample hold result of the peak value of the burst data thus read is read from the servo processing circuit 9 and the head is controlled (by controlling the voice coil motor 5 via the motor driver 6) according to the read data. 2 is moved to a target cylinder and performs head positioning control for positioning at the center (track center) of the target cylinder.

The CPU 10 also performs an alternative process of assigning an alternative destination sector to a defective sector. CPU10
In this alternative process, the spare track 104 and the physical position of the defective sector
In consideration of the time required for seeking until the replacement, the replacement destination sector is determined so as to minimize the execution time in accessing the sector on which the replacement process has been performed.

In addition, the CPU 10 also controls transfer of read / write data by controlling the HDC 14. The CPU 10 has a ROM (Read Only) as a non-volatile memory storing a control program (firmware) for controlling each unit in the magnetic disk device.
Memory) 11, a RAM (Random Acc.) As a rewritable volatile memory for providing a work area of the CPU 11 and the like.
ess memory) 12 and an electrically erasable and programmable EEPROM (EEPROM) as a rewritable nonvolatile memory.
ogrammable Read Only Memory) 13 is connected.

In the RAM 12, when the apparatus shown in FIG.
The spare track use status table 111 shown in FIG. 3 and the alternative destination allocation status table 112 (including the information on the system area) shown in FIG. 4 are read. The EEPROM 13 stores parameters for controlling the magnetic disk device, such as the number of data sectors in each zone of the disk 1, the number of data sectors in each servo sector 101, the offset between the servo area 102 in the servo sector 101 and the first data sector, It is used for storing a table of parameters such as data sector intervals. In FIG.
Of the tables stored in the EEPROM 13,
5 shows an example of a data structure of a table (sector number table per zone) 131 indicating the number of data sectors for each zone related to the present invention. In FIG. 5, Zm indicates an innermost zone (zone Z2 in the example of FIG. 2) of the disk 1. The cylinder range of the zone Zm is Sm-1 to Sm, and the number of data sectors is M. Is shown.

The CPU 10 is also connected to a disk controller (HDC) 14. The HDC 14 controls communication of commands and data with the host device, and also controls data communication with the read / write IC 8 (via the disk 1). In this HDC 14,
Read / write data is stored in a cache manner,
For example, a buffer memory (buffer RAM) 15 composed of a RAM or the like and a host interface 16 are connected. The host interface 16 serves as an interface between the HDC 14 and the host device.
Reference numeral 4 communicates commands and data with the host device via the host interface 16.

Next, a description will be given of a replacement process for a defective sector in the configuration of FIG. Now, in the magnetic disk drive of FIG. 1, tracks 6 on the disk 1 shown in FIG.
01 sector (data sector) 602 is normally read /
Since the write access could not be performed, the read / write access is retried, and even if the retry is performed a predetermined number of times, the access was not successful.
Is determined to be a defective sector.

In such a case, the CPU 10 performs an alternative process of allocating the defective sector 602 to any one of the spare tracks 104 according to the flowchart shown in FIG.

First, the CPU 10 takes the time required to seek the head 2 from the track 601 where the defective sector 602 exists to the spare track 104 (seek time).
Ts is calculated from the cylinder number of the track 601 and the cylinder number of the spare track 104 (step 70).
1). For this seek time (scheduled seek time) Ts, a correspondence table between the cylinder number difference and the seek time is prepared in advance, and the track 60 where the defective sector 602 exists is prepared.
By referring to the table based on the difference between the cylinder number of No. 1 and the cylinder number of the spare track 104, it is possible to calculate without performing calculations. This table is also stored in the system area in the same manner as the spare track use status table 111 and the like.
By reading the data into the H.12, high-speed table reference can be realized.

Next, the CPU 10 determines the calculated seek time T
s is the time required for one rotation of the disk 1 (one rotation time) T
The remainder Tm is calculated by dividing by C (step 70).
2). Next, the CPU 10 checks whether or not the calculated remainder Tm is shorter than the half rotation time (of the disk 1) (whether or not longer than the half rotation time) (step 70).
3). This means that the fractional part of the value (Ts / Tc) obtained by dividing the seek time Ts by one rotation time Tc of the disk 1 is １ ／.
It is equivalent to checking if it is less than.

It is not always necessary to perform steps 701 and 702 for the determination in step 703. However, for this purpose, the seek time between the track number of each track on the disk 1 and the cylinder number of the spare track 104 (the number of cylinders assumed to seek to the spare track) is set as the difference between the two. Remainder Tm of value divided by one rotation time Tc of disk 1
Is preliminarily classified into a range in which the rotation time is less than 1/2 rotation time and a range in which the rotation time is equal to or longer than 1/2 rotation time, and a correspondence table (remainder determination table) 801 as shown in FIG. System area or EEPROM 13
It is necessary to prepare it inside.

In the case of the table shown in FIG. 8, if the difference Δ between the cylinder number of the spare track 104 and the cylinder number of the track 601 where the defective sector 602 exists (that is, the number of cylinders to be sought) is within the range of 0 or more and less than N1. If
If the Tm is less than 1/2 rotation time and is in the range of N1 or more and less than N2, the Tm is 1/2 rotation time or more, and if the Tm is in the range of N2 or more and less than N3, the Tm is 1 / rotation time.
It is shown that the time is less than two rotation times.

Therefore, the track 601 on which the cylinder number of the spare track 104 and the defective sector 602 are present
The above Tm, that is, the seek from the track 601 where the defective sector 602 exists to the spare track 104 can be performed simply by determining the difference range of the cylinder number in the table of FIG. Time Ts
Is divided by one rotation time Tc of the disk 1 to determine whether the remainder Tm is less than 1/2 rotation time (whether or not it is 1/2 rotation time or more).

If the result of the determination in step 703 is that the remainder Tm is less than 1/2 rotation time,
U10 is a sector (spare sector) 60 located at a physical position on the opposite side of the physical position of the defective sector 602 (with respect to the center of the disk 1) from the spare track 104.
3a is selected as a first candidate of an alternative destination sector, and its sector number (data sector number) is set as a base sector number f for searching for an alternative destination sector (step 70).
4). On the other hand, if the remainder Tm is not less than 回 転 rotation time (if it is １ ／ rotation time or more), the physical location of the defective sector 602 (with respect to the center of The sector (spare sector) 603b located at the same physical position as the target position is selected as the first candidate for the replacement destination sector, and its sector number (data sector number) is set to the base sector number f for searching for the replacement destination sector. (Step 705).

Here, the base sector number f is i, the sector number of the defective sector 602, Zn is the zone to which the track 601 in which the defective sector 602 exists, N is the number of data sectors in the zone Zn, and the spare track 104 is If the zone to which Zm belongs and the number of data sectors in the zone Zm is M, if the remainder Tm is less than 1/2 rotation time, an integer part of f = {(i / N) * M + (M / 2)} ... (1) If the CDR method is not applied to the disc 1, N = M.

When the remainder Tm is equal to or longer than 1/2 rotation time, the base sector number f is obtained by the calculation of f = (i / N) * M, an integer part (2).

When obtaining the base sector number f for the search for the alternative sector, the CPU 10 sets the offset value g for the search for the alternative sector to the initial value 0 (step 706).

Next, the CPU 10 adds the current offset value g to the base sector number f, and uses the spare sector of the sector number indicated by the added value f + g (of the spare sectors in the spare track 104) as the replacement destination sector. Is determined by referring to the spare track use status table 111 (step 70).
7).

If the spare sector with the sector number f + g is not used, the CPU 10 determines the spare sector as a substitute sector for the defective sector 602 and (R
The status of the spare sector in the spare track use status table 111 (read in the AM 12) is set to “use status”, and the position of the defective sector 602 is stored in the alternative destination assignment status table 112 (read in the RAM 12). An alternative process of registering information (head number, cylinder number, and sector number) and position information of a spare sector in the spare track 104 determined as an alternative of the defective sector is executed (step 708).

On the other hand, if the spare sector having the sector number f + g has already been used, the CPU 10 increments the current offset value g by one in order to calculate the sector number of the spare sector adjacent to the spare sector (step 709). ). Then, the CPU 10 subtracts the offset value g after +1 from the base sector number f, and (of the spare sectors in the spare track 104) the spare sector of the sector number indicated by the subtraction value f-g, that is, the spare sector which is used first. G (=
1) It is determined by referring to the spare track use status table 111 whether or not the spare sector before the sector is being used as a replacement destination sector (step 71).
0).

If the spare sector having the sector number fg is not used, the CPU 10 determines the spare sector as a substitute sector for the defective sector 602, and sets the spare sector having the sector number f + g to the defective sector 60.
The same replacement process as when the second sector is determined as the second sector is executed (step 708).

On the other hand, if the spare sector with the sector number fg has already been used, the process proceeds to step 707, and the spare sector with the sector number indicated by f + g, that is, the spare sector determined to be used first. It is determined whether a spare sector after g (= 1) sectors is used as a replacement destination sector.

If the spare sector with the sector number f + g is not used, the CPU 10 determines the spare sector as a substitute sector for the defective sector 602 and executes a substitute process (step 708). On the other hand, if the spare sector of the sector number f + g has already been used, the CPU 10 returns to step 709 again and increments the offset value g at that time by +1.

As described above, the seek time (scheduled seek time) Ts from the track 601 where the defective sector 602 exists to the spare track 104 is less than １ ／ of one rotation time Tc of the disk 1, or more than 1/3. The seek time Ts is set to be equal to one rotation time Tc of the disk 1 so as to be less than twice.
When the remainder Tm of the value divided by the following is less than 1/2 rotation time, the spare sector 603a at the physical position on the opposite side to the physical position of the defective sector 602 becomes the first of the replacement destination sectors.
(Step 704).

If the spare sector 603a is not yet used (as a replacement destination sector) (steps 706 and 707), the spare sector 603a is replaced with a replacement destination sector of the defective sector 602 (step 708). . On the other hand, if the spare sector 603a has already been used (as a replacement destination sector) in the previous replacement process (step 707), the spare sector 6
03a, the spare sector 603a-1 immediately before the spare sector 603a, the spare sector 603a + 1 immediately after the spare sector 603a, and the spare sector 603a-2 immediately before the spare sector 603a.
, The spare sector 60 after the spare sector 603a
Unused spare sectors are searched in the order of the spare sector closest to the spare sector 603a, such as 3a + 2... (709, 710, 707), and the corresponding spare sector is replaced with a replacement destination sector of the defective sector 602 (step). 708).

On the other hand, the seek time (scheduled seek time) Ts from the track 601 where the defective sector 602 exists to the spare track 104 is equal to one rotation time T of the disk 1.
The remainder Tm obtained by dividing the seek time Ts by one rotation time Tc of the disk 1 is not less than 1/2 rotation time, such as 1/2 times or more and less than 1 time of c or 3/2 times or more and less than 2 times. In the case (when the rotation time is more than 1/2 rotation time), the defective sector 6
The spare sector 603b located at the same physical position as the physical position No. 02 is selected as the first candidate of the replacement destination sector (step 705).

If the spare sector 603b is not yet used (as a replacement destination sector) (steps 706 and 707), the spare sector 603b is replaced with a replacement destination sector of the defective sector 602 (step 708). . On the other hand, if the spare sector 603b has already been used (as a replacement destination sector) in the previous replacement process (step 707), the spare sector 6
03b, the spare sector 603b-1 immediately before the spare sector 603b, the spare sector 603b + 1 immediately after the spare sector 603b, and the spare sector 603b-2 immediately before the spare sector 603b.
, The spare sector 60 after the spare sector 603b
Unused spare sectors are searched in the order of the spare sector closest to the spare sector 603b, such as 3b + 2... (709, 710, 707), and the corresponding spare sector is replaced by the replacement sector of the defective sector 602 (step). 708).

By performing the above-described substitution processing, an increase in the execution time when reading / writing to a continuous sector group including the substitution-processed sector after the substitution processing is shown in FIG. The seek time (Ts) from the track 601 having the defective sector 602 to the spare track 104 is １ ／ of one rotation time (Tc) of the disk 1.
The read access when the spare sector 603a is assigned as the replacement destination of the defective sector 602 as an alternative destination is as follows.

First, the CPU 10 reads the sector immediately before the sector (defective sector) 602 subjected to the replacement processing, and seeks the head 2 to the spare track 104 according to the replacement destination allocation status table 112. Since the seek time at this time is less than half the rotation time of the disk 1, the seek is completed before the replacement destination sector (spare sector) 603a passes through the head 2, and the seek time of the replacement destination sector (spare sector) 603a is reduced. Reading can be performed without waiting for the rotation of the disk 1.

When the CPU 10 reads the replacement destination sector (spare sector) 603a, the CPU 10 performs replacement processing from the spare track 104 to read the next sector, that is, the sector immediately following the replacement processed sector (defective sector) 602. Original track 6 with sector (defective sector) 602
01 seeks the head 2. This track 104,6
01 is 1/1 of one rotation time of the disk 1.
Since it is less than twice, the seek is completed before the next sector of the sector 602 passes the head 2 and the sector 602
Can be read without waiting for rotation.

As a result, even when reading a sector group including the sector subjected to the substitution processing, the execution time of one rotation time of the disk 1 is shorter than when reading a group of sectors not including the sector subjected to the substitution processing. The alternative destination can be read only by increasing, compared to the conventional (seek time to spare track + rotation wait time to alternative destination sector + seek time to original track + rotation wait time to next sector) Thus, the increase in execution time can be minimized.

Similarly, when reading a sector group including the sector subjected to the replacement processing, for example, the tracks 601, 10
4 seek time is 1/2 of one rotation time of disk 1.
If it is not less than twice and less than 1 time, the execution time is increased only by 2 rotation times, and is 1 time or more of 1 rotation time of the disk 1.
If it is less than twice, the execution time is increased by only 3 rotation times, and if it is 3/2 times or more and less than 2 times the rotation time of the disk 1, the execution time is increased by only 4 rotation times, The increase in execution time can be minimized.

In the above embodiment, the spare track 104 is described as being prepared on the innermost circumference (of the data area) of the disk 1, but the present invention is not limited to this. For example, the spare track 104 may be prepared on a track (an intermediate track of the disk 1) that can be sought in the same time from the innermost track (of the data area) and the outermost track of the disk 1. In this case, even if the sector subjected to the substitution processing exists on the outer peripheral side of the disk 1, the increase in the execution time at the time of accessing the sector subjected to the substitution processing can be further reduced.

In the above embodiment, only one spare track 104 is provided on each surface of the disk 1. However, a plurality of spare tracks may be prepared. In this case, from all the tracks on the disk 1 (tracks in the data area), the spare track closest to the track is replaced with 1/1/1 of the disk 1.
If a plurality of spare tracks are distributed and arranged at positions where seeks can be performed within two rotation times, access to (alternate sector groups including) sectors that have been subjected to substitution processing can be performed most efficiently.

In the above embodiments, the magnetic disk device has been described. However, according to the present invention, a spare track for relocating a defective sector is secured on a recording medium (disk), and when a defective sector is detected, the defective track is detected. The present invention is applicable to general data recording / reproducing devices other than magnetic disk devices, such as magneto-optical disk devices, as long as the sector replacement destination sector is selectively assigned from spare tracks.

[0068]

As described above in detail, according to the present invention, in the replacement process for allocating a replacement destination sector to a defective sector, when seeking from the track in which the defective sector exists to the spare track, In consideration of the time required for the disk, the remainder of the seek time divided by the rotation time of the disk is used to select one of the spare tracks from the physical position opposite to the physical position of the defective sector with respect to the center of the disk. Since either the spare sector at the position or the spare sector at the same physical position as the defective sector with respect to the center of the disk is determined as the replacement destination sector for the defective sector, the replacement processing has been completed. Can determine an alternative destination sector that minimizes the execution time in accessing a given sector, resulting in lower performance due to alternative processing. It can be suppressed to a minimum.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a magnetic disk drive according to an embodiment of the present invention.

FIG. 2 is an exemplary conceptual view showing a typical format example of a disc 1 applied in the embodiment.

FIG. 3 is an exemplary conceptual diagram showing a data structure example of a spare track use status table 111 applied in the embodiment.

FIG. 4 is an exemplary conceptual diagram showing an example of the data structure of an alternative destination assignment status table 112 applied in the embodiment.

FIG. 5 is an exemplary conceptual diagram showing an example of the data structure of a zone number per sector table 131 applied in the embodiment;

FIG. 6 is an exemplary view showing a positional relationship between a defective sector and a spare sector which is a candidate for an alternative destination sector in order to explain replacement processing for a defective sector in the embodiment;

FIG. 7 is a flowchart for explaining a replacement process for a defective sector in the embodiment.

FIG. 8 shows whether a remainder obtained by dividing a seek time from a track having a defective sector to a spare track by one rotation time of the disk 1, which is necessary when determining an alternative destination sector in the replacement processing, is less than 1/2 rotation time; FIG. 9 is a conceptual diagram showing an example of the data structure of a remainder determination table 801 that can be used for determining whether or not there is no data.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Disk, 2 ... Head, 10 ... CPU (alternative destination sector determination means, determination means) 11 ... ROM, 12 ... RAM, 13 ... EEPROM, 104 ... Spare track, 111 ... Spare track use status table, 112 ... Alternative destination Allocation status table, 131 ... Zone number table per zone. 601: track (track with defective sector 602), 602: defective sector, 603a-2, 603a-1, 603a, 603a + 1, 60
3a + 2, 603b-2, 603b-1, 603b, 603b +
1, 603b + 2 ... spare sector. 801: remainder determination table (determination table means).

Claims (10)

[Claims] 1. A data processing apparatus comprising: a disk in which a spare track including a plurality of spare sectors for relocating a defective sector is secured; and a replacement process for determining and assigning a replacement destination sector of the defective sector from among the spare tracks. In the recording / reproducing apparatus, an alternative destination determining means for determining an alternative destination of a defective sector, comprising: a seek time required to seek from a track where the defective sector exists to the spare track; and a rotation time of the disk. Based on the determined value, from among the spare tracks, a spare sector at a physical position opposite to the physical position of the defective sector with respect to the center of the disk, or the defective sector with respect to the center of the disk One of the spare sectors at the same physical position as the physical location of the defective sector Data recording and reproducing apparatus comprising the alternative destination sector determining means for determining as a connector. 2. A data for performing a replacement process, comprising a disk in which a spare track including a plurality of spare sectors for relocating a defective sector is secured, and determining and assigning a replacement destination sector of the defective sector from among the spare tracks. In the recording / reproducing apparatus, an alternative destination determining means for determining an alternative destination of a defective sector, wherein a seek time required for seeking from a track where the defective sector exists to the spare track is divided by one rotation time of the disk. Based on the remainder, from among the spare tracks, a spare sector at a physical position opposite to the physical position of the defective sector with respect to the center of the disk, or the defective sector with respect to the center of the disk One of the spare sectors at the same physical position as the physical location of the defective sector Data recording and reproducing apparatus comprising the alternative destination sector determining means for determining as a connector. 3. A data which is provided with a disk in which a spare track including a plurality of spare sectors for relocating a defective sector is secured, and which executes an alternative process of determining and assigning an alternative destination sector of the defective sector from among the spare tracks. In the recording / reproducing apparatus, when determining the replacement destination of the defective sector, the remainder obtained by dividing the seek time required for seeking from the track where the defective sector exists to the spare track by one rotation time of the disk is １ ／ rotation. Discriminating means for discriminating whether or not the time is less than a time; as a result of the discrimination by the discriminating means, if the remainder is less than 1/2 rotation time, the spare track is shifted from the center of the disc to the center of the disc; A spare sector at a physical position opposite to the physical position of the defective sector is determined as a replacement destination sector for the defective sector, and If the remainder is equal to or longer than 回 転 rotation time, a spare sector located at the same physical position as the physical position of the defective sector with respect to the center of the disk from among the spare tracks is replaced with a replacement destination of the defective sector. A data recording / reproducing apparatus comprising: an alternative destination sector determining means for determining a sector. 4. The replacement destination sector determination means, if the spare sector determined as the replacement destination sector has already been used as a replacement destination sector for another defective sector, redetermines the replacement destination sector, and 4. The data recording / reproducing apparatus according to claim 1, wherein a spare sector closest to the spare sector determined as the replacement destination sector among the spare sectors is newly determined as a replacement destination sector. 5. A format according to a CDR (Constant Density Recording) method in which the disk is divided into a plurality of zones in a radial direction, wherein the replacement destination sector determining means sets a sector number of the defective sector to i, Assuming that the zone to which the track having the defective sector belongs is Zn, the number of data sectors in the zone Zn is N, the zone to which the spare track belongs is Zm, and the number of data sectors in the zone Zm is M, the sector number of the replacement destination sector If the remainder is less than 回 転 rotation time, the integer part of f = {(i / N) * M + (M / 2)} is calculated. The data recording / reproducing apparatus according to claim 3, wherein f is calculated by calculating an integer part of f = {(i / N) * M}. 6. Assuming that each track on the disk is the defective track, the remainder of the difference between the cylinder number of each track and the cylinder number of the spare track is less than 1/2 rotation time. Range and 1/2
A determination table for registering a range equal to or longer than the rotation time, wherein the determination unit refers to the determination table based on a difference between a cylinder number of a track in which the defective sector exists and a cylinder number of the spare track. 4. The data recording / reproducing apparatus according to claim 3, wherein it is determined whether or not the remainder is less than 1/2 rotation time. 7. A data having a disk in which a spare track including a plurality of spare sectors for relocating a defective sector is secured, and performing a substitution process for determining and assigning a substitution destination sector of the defective sector from among the spare tracks. A method for determining an alternative destination sector in a recording / reproducing apparatus, comprising: a seek time required to seek from a track having a defective sector to a spare track;
Based on a value determined by the rotation time, from among the spare tracks, a spare sector at a physical position opposite to the physical position of the defective sector with respect to the center of the disk;
Alternatively, one of the spare sectors located at the same physical position as the physical location of the defective sector with respect to the center of the disk is determined as a replacement destination sector for the defective sector. . 8. The replacement destination sector according to claim 7, wherein a value determined by the seek time and one rotation time of the disk is a remainder obtained by dividing the seek time by one rotation time of the disk. Decision method. 9. A data having a disk in which a spare track made up of a plurality of spare sectors for relocating defective sectors is secured, and performing a substitute process for determining and assigning a substitute sector for a defective sector from among the spare tracks. A method for determining an alternative destination sector in a recording / reproducing apparatus, wherein when determining an alternative destination of a defective sector, a seek time required to seek from a track where the defective sector exists to the spare track is determined by one rotation time of the disk. It is determined whether or not the remainder is less than 1/2 rotation time. If the result of this determination is that the remainder is less than 1/2 rotation time, the spare track is moved from the spare track to the center of the disk. Determining a spare sector at a physical position opposite to the physical position of the defective sector as a replacement destination sector for the defective sector; If the remainder is equal to or longer than 1/2 rotation time, a spare sector located at the same physical position as the physical position of the defective sector with respect to the center of the disk is replaced with the defective sector from among the spare tracks. A method of determining an alternative destination sector, which is determined as a destination sector. 10. When the spare sector determined as the replacement destination sector has already been used as a replacement destination sector for another defective sector, the replacement destination sector is determined again, and the spare sector is determined as the replacement destination sector among the unused spare sectors. 10. The replacement destination sector determination method according to claim 7, wherein a spare sector closest to the determined spare sector is newly determined as a replacement destination sector.