JPH09102170A - Disk recording and reproducing device and defect processing method applied thereto - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently process a defect by sequentially adding newly found defect information and efficiently using the defect information necessary for processing the defect in a system to use a non-volatile and DRAW type memory such as flash EEPROM. SOLUTION: Defect information in production and defect information after production newly found when a device operates are stored by using flash EEPROM 14. The defect information after production is, is contrast to the defect information in production, recorded in a specific area of the flash EEPROM 14 in finding order as added information. The defect information in production includes flag information which indicates the existence of the newly added defect information after production.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a defect management technique applied to a disk recording / reproducing device such as a hard disk device.

[0002]

2. Description of the Related Art Conventionally, in a disk recording / reproducing apparatus such as a hard disk apparatus (HDD), a disk surface is damaged during manufacturing of a disk as a recording medium or during an assembly process for mounting the disk inside the HDD. There is. If the damage on the disk surface is out of the allowable range, it is treated as a defect that makes the data recording / reproducing operation impossible.

In the HDD, a large number of concentric tracks are formed on the disk, and each track is divided into, for example, about 50 data sectors. This data sector is the HDD access unit. The HDD uses a head number (disk surface), track number (cylinder number),
And address information corresponding to the sector number is set.

Here, in the system in which the ID area is provided in the data sector, defect information relating to the above-mentioned defects is recorded in the ID area together with the sector number. The defect information is
It is the defect management information including the defect state of the defective sector (whether there is a defect) and the address of the replacement sector.

Based on this defect information, access to the defective sector is prohibited, and replacement with a prepared alternative sector (usually provided for each track on the disk surface) or an alternative track (replacement cylinder) is performed. The defect management process to be performed is executed.

However, in order to increase the data recording density of the disk, a format (ID-less recording format) system which is composed of data sectors having no ID area is being adopted. In this method, defect information (defect map) is stored in a memory (RAM) controlled by the CPU of the microcontroller or a sector buffer controlled by the disk controller (HDC).

The sector buffer is a buffer memory for storing read data transferred to the host computer or write data from the host computer.
Therefore, when the defect information is stored, the storage area of the sector buffer naturally decreases, and the efficiency of data transfer control with the host computer decreases.

The HDC has a read cache function by a pre-read operation at the time of data reproduction and a write cache function by a data accumulation operation at the time of data recording in order to improve data transfer efficiency. These functions require effective use of the read / write data storage area of the sector buffer. Therefore, the reduction of the storage area due to the defect information causes a significant decrease in the performance of the HDC.

Further, in the method of storing in the RAM, it is necessary to secure a dedicated recording area for storing the defect information on the disk or a backup power supply circuit of the RAM. Further, the defect information requires an operation (additional operation) of additionally recording the defect information newly discovered during the operation of the HDD together with the information recorded during the manufacture of the HDD. This additional recording operation cannot be dealt with by the method of storing in the RAM.

Therefore, a non-volatile memory, which is an electrically rewritable flash EEPROM (select)
locally erasable program
There is a method in which an available read only memory) is used as a memory for storing defect information.

The flash EEPROM is capable of erasing data in block units (32 KB or 64 KB) and recording operation in byte units. This flash EEPROM is used to store the defect information relating to the defective sector found in the disk inspection process in the HDD manufacturing process. Then, when the HDD is operating, the CPU of the microcontroller flashes the EEP.
The ROM is searched to determine whether the sector to be accessed is a defective sector. Based on this judgment result, H
The DC executes the above defect management processing.

[0012]

As described above, if the flash EEPROM is used to store defect information, the sector buffer is effectively used for the transfer control of host data (read / write data). Therefore, it is possible to solve the problem that the performance of the HDC is deteriorated, and it is possible to reliably store the defect information.

By the way, in the flash EEPROM, it is possible to invert the bit state reset in the erase (erase) state in the case of a write-once operation of adding newly found defect information to the recorded defect information. However, it is not possible to return the inverted data to the same erased state.

Specifically, when the cell content is "11111111" at the time of erasing, it is possible to set the bit state to "0" by the write operation, but conversely, the portion of "0" is set to "0". The write operation to "1" is impossible. If this writing operation is impossible, the erase operation is required.

In the erase operation of the flash EEPROM, it is possible to collectively erase all storage areas or the above-described block-unit batch erase. In the case of batch erasing of all storage areas, if the rewrite area is a part, it is necessary to temporarily save the data that needs to be retained in, for example, a sector buffer and write after the erase processing. Further, in batch erase in block units, if the size of the data group to be rewritten does not match the minimum erase block length, it is necessary to save the data that needs to be retained as in the above case.

Further, the flash EEPROM is normally limited in the number of times of writing and erasing. Therefore,
Since it is not possible to perform an additional write operation with an erase operation indefinitely, the method of simply adding the newly discovered defect information together with the fixed defect information at the time of manufacturing saves the defect information necessary for the defect processing. It will be impossible.

An object of the present invention is to provide a flash EEPROM.
In a method that uses a non-volatile additional write operation memory such as, the newly discovered defect information is sequentially added,
The defect information necessary for the defect processing can be effectively used so that a reliable and efficient defect processing can be achieved.

[0018]

The present invention is a disk recording / reproducing apparatus for storing defect information of a defective area detected at the time of manufacturing, for example, using a flash EEPROM and performing defect management processing based on this defect information. is there.

According to the present invention, the defect information of a defect area newly discovered during the operation of the apparatus is recorded in the flash EEPROM together with the defect information detected at the time of manufacturing. The new defect information is recorded in the specific area of the flash EEPROM in the order of discovery as additional information to the defect information detected in manufacturing. The defect information detected during manufacturing includes flag information indicating the newly added defect information, if any.

The defect management means searches the defect information of the flash EEPROM during the data recording / reproducing operation and confirms whether or not there is a defective sector included in the range to be accessed. At this time, the defect information detected at the time of manufacturing is searched, and the defect information newly added based on the flag information included in the defect information is searched.

With such a configuration, the flash EEP
In the ROM, only the defect information newly discovered during the operation of the device is added to the defect information detected at the time of manufacturing in the order of discovery. Therefore, in the operation of the flash EEPROM, the write operation of the flag information and the additional write defect information can be performed without the erase operation.

Further, as the defect management method of the present invention, only the defect information of the defect area detected at the time of manufacture is recorded in the flash EEPROM, and the defect information of the defect area newly discovered after the shipment of the apparatus is stored in a specific area on the disc. Record. The defect information recorded on the disk is loaded on the sector buffer when the device is started up, and is searched when the data is accessed.

With such a method, since the defect information detected during manufacturing is not stored in the sector buffer, the storage area of the sector buffer for the defect information can be reduced.

Further, in the rewriting operation of the flash EEPROM, normally, for example, a small HDD of 2.5 inches is used.
It is necessary to supply a voltage (12V) different from the driving power supply voltage (5V) of the above. Therefore, when the flash EEPROM is rewritten after the device is shipped, a 5V single-power-supply HDD requires a means for externally supplying the 12V voltage for the flash EEPROM.

Therefore, it is not necessary to prepare a special rewriting power source for the flash EEPROM by the method of recording the defect information in the flash EEPROM at the time of manufacturing and recording the newly discovered defect information in the disk after the shipment of the apparatus.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an HDD related to the present embodiment.
2 is a block diagram showing the system configuration of FIG. 2, FIG. 2 is a conceptual diagram for explaining defect information related to this embodiment, and FIG. 3 is a flash EEPRO related to this embodiment.
FIG. 4 is a conceptual diagram for explaining the storage state of M, and FIGS. 4 and 5 are flowcharts for explaining the operation of the present embodiment. (System Configuration) In the present embodiment, an H that uses a flash EEPROM 14 as a memory for storing defect information.
Assumes DD. The flash EEPROM 14 is
It is accessed by the CPU 11 of the microcontroller.

As shown in FIG. 1, the HDD includes a disk 1 which is rotated at a high speed by a spindle motor (SPM) 2, a head 3 held by a head actuator 4, a head amplifier 6, and a read / write. (R /
W) circuit 7.

The head actuator 4 is rotationally driven by a voice coil motor (VCM) 5 to move the head 3 in the radial direction of the disk 1. VCM5 and SPM2
Is a VCM / S integrated as a double driver
A drive current is supplied from the PM driver 9 to drive it.

The R / W circuit 7 exchanges read / write signals with the head 3 via the head amplifier 6.
The R / W circuit 7 reproduces the read signal from the head 3, reproduces the read data, and outputs it to the HDC 15.
Further, the R / W circuit 7 has a servo processing circuit 8, reproduces servo data from the read signal of the head 3, and outputs it to the microcontroller 10.

The microcontroller 10 is the main control unit of the HDD, and is a microprocessor (CPU) 11
And an A / D converter 12 and a D / A converter 13. The CPU 11 controls the flash EEPROM 14 related to the present embodiment, and executes a defect information recording operation and a search operation necessary for the defect management processing. A
The / D converter 12 converts the burst data output from the servo processing circuit 8 into digital data and converts it into a CPU.
11 is output. The D / A converter 13 converts the control amount of the movement control or the position control of the head 3 calculated by the CPU 1 into an analog signal and outputs it to the VCM / SPM driver 9.

The HDC 15 comprises an interface between the HDD and the host computer and a data controller. The HDC 15 temporarily stores read / write data in the sector buffer (RAM) 16 and executes data transfer control with the host computer. The HDC 15 executes a defect management process for the data sector to be accessed, based on the defect information from the microcontroller 10. (Defect Information Format) The defect information of this embodiment is
As shown in FIG. 2, it comprises a defect record defined for each defective sector. The defective record includes address information of a defective sector detected as a defective area and other information. The address information includes a head number (disk surface) to which the corresponding defective sector belongs, a track number (upper and lower sides of the cylinder code), and a sector number.

The other information includes address information (upper and lower) for designating an alternative sector of the defective sector, an alternative format (method of alternative type), and flag information related to this embodiment.

The alternative format is information for designating, for example, a sector skip method or a track-based alternative method. In the sector skip method, a defective sector is made unusable, access is skipped (skip), and a spare sector provided in the track is used. Therefore, in the case of the sector skip method, since the replacement process is not executed in units of sectors, the address of the replacement destination is unnecessary. Further, in the track-based alternative method, the sector number in the defective record and the sector number of the alternative destination address are unnecessary.

Here, the flag information is made up of 2-bit flags F0 and F1, and is made up of a validity judgment flag F0 and a record insertion (additional writing) instruction flag F1. Validity judgment flag F
0 is a flag for determining whether or not the record is valid. For example, when the replacement destination sector becomes a defective sector, the validity determination flag F0 is set to indicate that the address information of the replacement destination sector of the record is invalid.

A record insertion (additional write) instruction flag (hereinafter referred to as an additional write flag) F1 is a flag for indicating the existence of an additional write defect record described later. Here, in the write-once method as in the present embodiment, when the replacement destination sector becomes a defective sector, the record itself is invalidated without changing the address information of the replacement destination sector (validity determination flag F
Set of 0). Then, the replacement destination sector is added as a newly discovered defective sector with the defective record.
This additionally recorded defect record group is referred to as subsequent defect information in this embodiment. On the other hand, defect information that is detected and fixedly recorded at the time of manufacturing the HDD is referred to as manufacturing defect information.

That is, in this embodiment, as shown in FIG. 3A, the manufacturing defect information consisting of defect record groups of defective sectors detected in the disk inspection process at the time of manufacturing the HDD is predetermined in the flash EEPROM 14. Is recorded in the storage area of. Further, as shown in FIG. 3B, the subsequent defect information is recorded in a predetermined storage area of the flash EEPROM 14 in the order of detection every time it is newly discovered during the operation of the HDD. (Defect Management Process) The defect management process of this embodiment will be described below with reference to the flowcharts of FIGS. 4 and 5.

When the target address to be accessed is set from the HDC 15, the CPU 11 causes the flash EEPRO.
The M14 is accessed to search the manufacturing defect information (manufacturing defect map) (steps S1 and S2). That is, it is determined by searching the manufacturing defect information whether the defective sector exists in the data sector included in the address range of the access target. Here, the search operation (search operation) method is, for example, a binary search (binary search).

If a defect sector included in the access range exists in the manufacturing defect information, the sector number is used as the internal memory (RA) of the microcontroller 10, for example.
M) (YES at step S3, S4).

Next (including the case where there is no defective sector), the additional recording flag F of each defective record of the manufacturing defect information.
Check 1 (step S5). Here, as a result of checking the flag F1 of the defect record that is larger than the target address and has the closest address, if the additional recording flag F1 is set, the process moves to the process of searching the subsequent defect information (steps S6 and S7). .

If it is determined that there is no defective sector, the data recording / reproducing operation is executed for the data sector included in the access target (step S8). Subsequent defect information (subsequent defect map) is stored in the HDD as described above.
The defective record group newly recorded during the operation is recorded in the order of detection. Therefore, CPU1
1 will retrieve all defect records of the subsequent defect information.

The CPU 11 reads the first defective record from the flash EEPROM 14 and checks whether the head number and the track number, which are the address information of the record, correspond to the defective sector on the track where the target sector exists (step). S11).

If they do not match, the reference pointer for reading the next defective record is updated, and the processing from step S10 is repeated (steps S12, S13, S1).
4). This process continues until all defective records of the subsequent defect information are read.

If they match, it is checked whether or not the sector number of the defective record is included in the range to be accessed (YES in step S12, S16). This is because even defective sectors on the same track are not always included in the access range. If not included, the reference pointer is updated to read the next defective record (NO in step S17, S1).
3).

If there is a defective sector included in the access range, the defective sector number is stored in, for example, the internal memory (RAM) of the microcontroller 10 (YES in step S17, S18).

If no defective sector is found from the manufacturing defect information, the defective sector found from the subsequent defect information is saved as a new defect position. When a defective sector is found in the manufacturing defect information, the sector number of the subsequent defect information is compared with the sector number of the manufacturing defect information, which is the head sector number of the access target, and the difference is found. The smaller sector number is saved as a new defect position.

Here, when a new defective sector is discovered during the operation of the HDD, the CPU 11 relates the new defect record to the subsequent defect information, the update of the number of subsequent defect records, and the manufacturing defect information. Each operation of setting the additional recording flag F1 of the defective record is executed.

As described above, according to this embodiment, the defect information for searching the defective area (sector unit) of the disk 1 is stored in the flash EEPROM 14. Therefore, the defect record corresponding to the newly discovered defective sector can be additionally written as the subsequent defect information without using the sector buffer 16.

In this embodiment, since the defect information at the time of manufacturing and the subsequent defect information which is new defect information are separately stored, the erase operation of the flash EEPROM erases all storage areas at once or collectively. There is no need to perform block-based batch erase. That is, the manufacturing defect information is recorded at the time of manufacturing the HDD, and thereafter, there is no rewriting change other than the flag information F0 and F1. Further, since the subsequent defect information is recorded in the order of detection, there is no rewriting change after being recorded by one writing operation.

The setting operation of the flag information F0 and F1 is realized without utilizing the erase operation by utilizing the characteristics of the flash EEPROM as described above.
That is, in FIG. 2, “01h” is set as the alternative format code.
Is specified and the flag information F0 and F1 are the upper 2 bits. At this time, as a value that can change the flag state by additional writing, for example, "1100000"
1B ”code. In order to additionally write the information of set (0 as the bit state) when the position of the flag information F1 is bit 6, "10000001B" may be additionally written. By this additional recording operation, the recording state is "1000.
0001B ".

In short, since the erased bit state (1) can be inverted, the bit state (1) is changed to the bit state (0) in order to set (0) as an additional write operation of the flag state. It will be reversed.
Therefore, it is possible to realize the operation of setting (not changing) only the flag information of the manufacturing defect information without performing the erase operation of the batch erase of all the storage areas or the block unit.

In general, a memory such as a ROM is provided with inspection data for determining whether the contents are correct. This inspection data uses a checksum or the like and is arranged at a specific address on the memory.

When the power is turned on, the CPU executes the calculation of the checksum (exclusive logical operation of all data) on all the data in the memory, and the result of this operation and the result previously arranged in the memory. And a diagnostic process for determining that the memory is normal if the two match. Here, when the contents of the memory are rewritten,
Of course, the checksum calculation result will change. Even in such a case, by adopting the write-once operation method of the present embodiment, the inspection data can be updated without performing the erase operation by utilizing the characteristics of the flash EEPROM. (Application of this Embodiment) In this embodiment, as described above, the subsequent defect information found after the shipment of the device at the time of manufacturing is recorded in a specific area of the disc. In other words, this is a method in which after the defect information is recorded in the flash EEPROM 14 during manufacturing, the write operation of the defect information is not executed in the flash EEPROM 14.

Therefore, in particular, when the flash EEPR is applied to an HDD having a single power supply voltage specification of, for example, 5V.
An external power supply for supplying a 12 V voltage for rewriting the OM 14 can be eliminated.

Here, the subsequent defect information recorded in a specific area of the disc is loaded into, for example, a sector buffer when the apparatus is activated, and the defect information is retrieved from the sector buffer when data is accessed. Therefore, the defect information search operation is executed for both the flash EEPROM 14 and the sector buffer.

Since the flash EEPROM 14 has no additional write operation, no additional write flag exists. The defect management information consists of a defective address and an alternative address,
Since there is no additional writing, the replacement destination address for the defective address detected during manufacturing cannot be changed.

When the alternative destination becomes defective after the device is shipped, the alternative destination should be originally registered as a defect in the defect management information, but the search processing time becomes long,
The search operation is less efficient. That is, it is necessary to determine whether or not there is a defective area in the access range, and if there is a defective area, it is necessary to perform a re-search operation to determine whether the replacement destination or the defective area is present.

Therefore, the changing process of the alternative destination is executed. As a specific condition, the address of the defective area detected at the time of manufacturing is registered in the flash EEPROM 14, but the defect information of the same address is recorded in the sector buffer. If the replacement information for the same address exists in both the flash EEPROM 14 and the sector buffer, the defect information on the sector buffer is prioritized and the defect information on the sector buffer is referred to as the replacement destination.

[0058]

As described above in detail, according to the present invention, in the defect management system of the disk, the flash E
A non-volatile memory such as an EPROM capable of additional recording is used to sequentially record the manufacturing defect information and the newly discovered defect information and store the subsequent defect information. In the defect management processing, each of the manufacturing defect information and the subsequent defect information is searched in two stages. Therefore, it is possible to surely update and retrieve the defect information without performing the erase operation of the memory. As a result, as a result, reliable and efficient defect processing can be achieved.

[Brief description of the drawings]

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

FIG. 2 is a conceptual diagram for explaining defect information related to the present embodiment.

FIG. 3 is a flash EEPROM related to the present embodiment.
FIG. 6 is a conceptual diagram for explaining the storage state of the memory.

FIG. 4 is a flowchart for explaining the operation of the embodiment.

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

[Explanation of symbols]

 1 ... Disk (recording medium) 2 ... Spindle motor (SPM) 3 ... Head 4 ... Head actuator 5 ... Voice coil motor (VCM) 6 ... Head amplifier 7 ... Read / write circuit (R / W circuit) 8 ... Servo processing circuit 9 ... VCM / SPM driver (double driver) 10 ... Micro controller 11 ... CPU 12 ... A / D converter 13 ... D / A converter 14 ... Flash EEPROM (defect information storage means) 15 ... Disk controller (HDC) 16 ... Sector buffer

Claims (5)

[Claims] 1. A disk recording / reproducing apparatus having a disk as a recording medium, and storing defect information designating a defective area in which data recording / reproducing operation cannot be performed on the disk, which is non-volatile. Non-volatile rewritable storage means for storing, as the defect information, address information of the defect area and flag information indicating that defect information of a newly discovered defect area is added. And rewritable storage means for storing defect information of the newly discovered defect area, and for searching and accessing the first storage means during data recording / reproducing operation. The presence or absence of defect information included in the target range is confirmed, and the second storage unit is searched based on the flag information to determine whether the defect information included in the access range exists. A disk recording / reproducing apparatus comprising: a defect management unit for confirming nothing. 2. A disk recording / reproducing apparatus having a disk as a recording medium, and storing defect information designating a defective area in which data recording / reproducing operation is disabled on the disk, wherein the defect information A first memory for storing flag information indicating that the address of the defective area, the address of the alternative area of the defective area, and the defect information of the newly discovered defective area are added. Means, flash memory, and second storage means for storing defect information of the newly discovered defect area; and, during data recording / reproducing operation, the first storage means is searched for access targets. The presence or absence of defect information included in the range is confirmed, and the second storage unit is searched based on the flag information to be included in the range of the access target. Defect management means for confirming the presence / absence of defect information, and the defect management means in the first storage means or the second storage means, if there is defect information included in the range of access target, the defect information And a control means for executing a data recording / reproducing operation by using the alternative area included in the above as a recording area to be accessed. 3. A disk, which is a recording medium, is provided, and defect information designating a defect area where data recording / reproducing operation is disabled on the disk is stored in a flash memory at the time of manufacturing the device, and based on the defect information. A defect management method for a disk recording / reproducing apparatus for performing defect management processing according to claim 1, wherein the defect information of a defect area newly discovered during operation of the apparatus is added to a specific area of the flash memory in the order of discovery, Recording flag information for indicating the presence of additional write defect information additionally written in the area as information included in the defect information related to the additional write defect information stored in the flash memory; and a data recording / reproducing operation. Sometimes, the flash memory is searched to check if there is any defect information included in the range to be accessed. And a step of confirming the presence or absence of the write-once defect information included in the range of the access target based on the flag information. 4. A manufacturing defect information and a device having a disk which is a recording medium, wherein a defect area in which a data recording / reproducing operation cannot be performed on the disk and which is detected at the time of manufacturing the device is designated. Of the disc recording / reproducing apparatus that stores the subsequent defect information in which a newly discovered defect area is specified in the flash memory in the flash memory, records the subsequent defect information in the order of detection, and executes defect management processing based on the defect information. A defect management method, wherein during a data recording / reproducing operation, a step of accessing the flash memory and first searching a defect area included in an access target range from the manufacturing defect information; Flag information included, which is flag information indicating the presence of defect information added as the subsequent defect information A step of checking, a step of accessing the flash memory to search for a defect area included in an access target range from the subsequent defect information when the flag information is set, the manufacturing defect information or the A defect management method comprising the step of storing defect information retrieved from subsequent defect information and executing a predetermined defect management process. 5. A disk, which is a recording medium, is provided, and defect information designating a defect area in which data recording / reproducing operation is disabled on the disk is stored in a flash memory at the time of manufacturing the device, and based on the defect information. A defect management method for a disc recording / reproducing apparatus for performing a defect management process, comprising: recording defect information of a defect area newly discovered during operation of the apparatus in a specific area on the recording medium; and recording data. During a reproducing operation, a step of searching for defect information of a defect area recorded in a specific area on the flash memory and the recording medium and confirming whether there is defect information included in an access target range is included. Defect management method.