JPH05174494A - Formatting method for disk memory - Google Patents

Abstract

PURPOSE:To surely control a head position at the time of writing data and to enhance the reliability of a long term of reading/writing the data by eliminating an adverse effect due to the defect of servo information on the disk surface of the disk memory of an intersector servo system. CONSTITUTION:A servo information inspecting means 40 is incorporated in the disk memory of the intersectors servo system and servo information S1 is read from the disk l surface by a servo information reading circuit 30 and the presence of the defect of respective servo information are inspected. Then, the position of the defect in a track T is detected when the defect is present and a sector S adjacent to the servo information SI having the defect in a formatting data editing means 60 is eliminated based on the inspected result. Then, the formatting data alternated by a spare sector set previously in respective tracks is edited and written into the track T.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk storage device such as a fixed disk device, in which servo information for detecting a head position is written between sectors as recording units of data in the disk. Formatting method.

[0002]

2. Description of the Related Art In a disk storage device, it is always required to increase its storage capacity. For this reason, when the number of tracks in the disk is increased and the data recording density in each track is increased, the position of the head becomes the center of the track. It is easy for read / write errors to occur even if it is slightly deviated from
Recently, an inter-sector servo system in which servo information for detecting the head deviation or off-track is written between the sectors has been widely adopted.
As is well known, as servo information of this system, burst servo in which a simple pattern is repeated at a narrow pitch is sequentially shifted in the radial direction and the circumferential direction of the disk, and is usually four points represented by A to D. Use the one written in
In addition to this, it is customary to write the track number in a recording pattern different from the data as the track collation information used when the head moves between tracks. In the disk storage device, the servo information and track number are first written on the disk to set a track, and then formatting is performed to set a sector which is a data recording unit.

In this inter-sector servo type disk storage device, a servo information reading circuit is incorporated and placed so that when reading and writing data, the servo information is read at narrow time intervals to detect the off-track amount, and this is eliminated. By constantly performing position correction control on the head, the occurrence of read / write errors is prevented. When data is read, even if an error should occur due to an unexpected cause such as vibration or shock, if the same data read trial or retry is repeated 1 to 3 times, the desired data can be read almost reliably. You can

However, if the data writing position is accidentally deviated from the track center due to vibration or shock at the time of writing the data, an error is likely to occur at the time of reading, and in the worst case, reading is repeated no matter how many times the retry is repeated. It can happen that you fail. To prevent this, it is effective to perform read verification each time data is written, and rewrite the data when a read error occurs, but this read verification waits for the disk to make one revolution. However, there is a problem that the access time at the time of writing becomes considerably long. Therefore, in the disk storage device of the inter-sector servo system, conventionally, the servo information is read in parallel with the write operation to detect the off-track amount, and the data is rewritten when it exceeds a predetermined limit set in advance. It is usually done.

[0005]

As described above, it should be possible to eliminate the error occurrence by reading the servo information between the sectors in parallel with the writing of the data and confirming that the off-track is within the allowable limit. However, in reality, there is a problem that the servo information itself cannot be read if the recording medium in the area where the servo information is written has a defect or a defect occurs during use. However, even if the servo information at a certain position cannot be read, the servo information before and after that can be read in many cases, so the position of the head when writing data to the sector adjacent to the defective servo information due to the off-track detected from it. It is possible to estimate the correctness of the above, and even if the write operation is advanced based on such estimation, there is practically no problem. But,
If the write operation based on the estimation of the head position is continued, an error may occur during a long period of use of the disk storage device. This is probably because, for example, the head may come into contact with the disk surface due to an untimely impact, and the recording medium may be seriously damaged.

It is an object of the present invention to solve such a problem and more accurately control and confirm the head position at the time of writing data to further improve the reliability of the read / write operation of the disk storage device.

[0007]

According to the present invention, there is provided a servo information reading circuit for reading servo information from a disk via a head in a disk storage device of the inter-sector servo system described above, and a read operation by the circuit. The servo information verification means that receives the servo information provided and verifies the presence or absence of the defect and detects the position of the defect, and the editing means of the formatting data are built in, and the spare sector is set in each track. This is achieved by causing the formatting data editing means to edit the formatting data in which the sector adjacent to the defective position of the servo information is replaced by the spare sector and writing it on the track based on the verification result.

The above-mentioned servo information verifying means is also provided with a function of correcting the head position based on the servo information read by the servo information reading circuit, so that a defect in the servo information can be detected when the head position is accurately controlled. It is advantageous to verify the existence. Further, since the track number is usually written in the servo information as described above, and this is also read by the servo information reading circuit, the servo information verifying means can detect the defect including the servo information and the track number. It is desirable to have a function to verify the presence or absence of.

The formatting method of the present invention is applied, of course, at the first formatting of the disk storage device. In addition to this, actually, the servo information verifying means described above is activated at any time during the period of use of the disk storage device, and the servo information is verified. When a defect of information is detected, the formatting data editing means is operated for the track including the defect and the track is reformatted to maintain the reliability of the read / write operation of the disk storage device at a high level for a long time. It is very advantageous in doing so. Further, in the method of the present invention, it is easy to have the servo information verifying means verify the presence / absence of a defect in the servo information for the track in which the data is being read / written when the disk storage device is used. It can be reformatted.

The sector adjacent to the defective position of the servo information to be replaced by the spare sector by the formatting data editing means may be the sector following the defective servo information, but it may be the sector before or after the sector in some cases. .. As the replacement of such a sector is advanced, it is possible that there will be no spare spare sector in a certain track. Therefore, in case of such a worst case, a spare sector track is set and placed in the disk surface. Is good. In addition, a sector management table is provided in association with the servo information verification means for managing the current state of sector substitution, and the physical address in the disk storage device of the read / write data specified by the logical address from the computer side is stored in this sector management table. It is desirable to put it so that it can be easily referenced and converted.

It should be noted that the servo information reading circuit in the above configuration is incorporated in the disk storage device in the form of hardware such as a gate array, and the servo information verifying means is provided in the control processor for the overall control of the device to edit the formatting data. The means are preferably implemented as software in the data processor for read and write data respectively.

[0012]

According to the method of the present invention, the occurrence of an error is prevented in advance by removing the sectors that may have a problem in reading and writing due to defective servo information and performing the formatting in which the spare sectors are replaced by the formatting. The reliability of the read / write operation of the disk storage device is always maintained at a high level.

Therefore, in the present invention, the disc information storage device is equipped with the servo information verifying means as described in the above paragraph, and the servo information reading circuit is made to read the servo information at the time of the initial formatting of the disc and the use after the device. hand,
Each servo information is verified whether or not there is a defect, and if there is a defect, the position within that track is detected, and based on the result, the formatting data editing means excludes the sector adjacent to the defective servo information and Formatting data replaced by a spare sector set in advance is edited and written in the track.

Therefore, according to the method of the present invention, there is no possibility that a so-called write error will occur in which data is written at an irregular head position in a sector adjacent to defective servo information, especially when writing data. If data is written at the proper head position, even if the reading fails once, it can be surely read by performing the above-mentioned retry unless the recording medium is newly scratched, so a read error occurs. Can be virtually eliminated.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1A shows an example of the configuration of a disk storage device that implements the formatting method according to the present invention.
(b) and (c) show how the servo information SI is written in the track T and the sector S is set. FIG. 2 is a flowchart showing the overall operation of the method of the present invention centering on the operation of the servo information verification means 40. In the embodiments described below, the disk storage device is a fixed disk device and the servo information SI
It is assumed that the disk 1 in which the track number TN and the track number TN are written is subjected to the first formatting for setting the sector S as a recording unit of data by the method of the present invention.

The mechanical portion of the disk storage device is shown in a simplified manner at the top of FIG. As is customary, the disk 1 is driven at a constant speed by an outer rotor type spindle motor 2 and the data reading / writing head 3 is supported by a swing arm type carriage 4 in the example shown in the drawing, and is an actuator which is a voice coil motor. 5 controls the radial position on the disc 1. On the lower left side is a data read / write signal processing circuit, which is a read / write circuit 6 connected to a plurality of heads 3 as usual, and a demodulation circuit for receiving the analog read signal RS and converting it into a signal of a predetermined modulation system. 7
And a sync separation circuit 8 and an encoder / decoder circuit 9 which receives the read signal RS after conversion and gives a write signal WS of the same system to the read / write circuit 6. The read / write circuit 6 puts the head 3 designated by the head selection command HS in a readable or writable state according to the read / write command RW.

In the disk storage device, a control processor 10 is usually incorporated for general control of the inside of the disc storage device, but in the example shown in the figure, another data processor 20 dedicated for handling the read / write data is incorporated. The internal bus
11 and an interface circuit 12 and an external bus 13 are connected to a computer (not shown) and interconnected via a communication bus 14. The control processor 10 is a read / write circuit 6
To the drive circuit 5a attached to the actuator 5 by issuing the head selection command HS and the read / write command RW described above.
CS is applied to control the position of the head 3. Further, the data processor 20 is connected to the encoder / decoder circuit 9, receives a serial pulse train signal obtained by decoding the read signal RS, converts it into parallel data, and puts it on the internal bus 11 via the RAM 21 or data from the internal bus 11. Is read and converted into a pulse train signal, which is applied to the encoder / decoder circuit, which is then encoded into the write signal WS and output to the read / write circuit 6.

In order to carry out the method of the present invention, a servo information reading circuit is added to the disk storage device configured as described above.
30 and incorporates servo information verification means in this embodiment.
40 is loaded on the control processor 10, and the formatting data editing means 60 is loaded on the data processor 20 as software.

The servo information reading circuit 30 reads the hatched portion between the sectors S in the track T shown in FIG. 1 (b) from the read signal RS, and this portion is as shown in FIG. 1 (c). The track number TN and the servo information SI are written in, and a short blank is usually placed at the beginning as a head mark SM indicating that the next is the servo information SI or the like. When the servo information reading circuit 30 detects this head mark SM, the detection signal DS
Is first sent to the servo information verification means 40, and then the track number TN and the read content RD of the servo information SI are output. The servo information SI of this embodiment is composed of four portions indicated by A to D in FIG. 1 (c) which are the above-mentioned burst servos as usual, and the magnitude of the signal read from the servo information reading circuit 30 is large. It is assumed that four digital values indicating the level are given to the servo information verification means 40 as the read content RD.

As shown in FIG. 1 (c), the sector S set in the track T is roughly divided into a collation code ID and an area for data DT. The collation code ID in this sector is a track number. , Sector numbers, etc. are written, and as is well known, this collation code ID is written in the area for each sector S during formatting.

Now that the structure of the disk storage device shown in FIG. 1 and the function of each part thereof have been described, the overall operation of the method of the present invention will be described with reference to the flow chart of FIG. FIG. 2 shows the operation steps of the servo information verification means 40 when the disk 1 is first formatted. In the first step S41 after the activation, for example, 0 is put in the track number variable i which specifies the track to be formatted, and the track on the outermost diameter side is usually specified. In the next step S42, a so-called seek operation of placing the head 3 on the i-th track Ti is performed. For this purpose, the drive circuit 5a of the actuator 5 may be given a control signal CS designating this track Ti.
Then, in this step S42, the sector number variable j in the track is set to 1, and the flow is shifted to step S43 in synchronization with the rotation of the disk 1, usually in synchronization with the index pulse generated from the spindle motor 2.

In step S43, it waits for the detection signal DS to arrive from the servo information reading circuit 30, and the operation is moved to the next step S44 each time it arrives, and the track number TN and the servo included in the above-mentioned read content RD and the servo are read. A servo value indicating the size of the four burst servos A to D in the information SI is read. Further, in this step S44, the off-track OT is calculated from these servo values A to D. In the case where the servo information SI is of the burst servo type as in this embodiment, A or B of these four servo values A to D becomes the maximum when the head 3 is near the center of the track, so that it is usually shown in FIG. The off-track OT can be easily calculated by CD like. When the deviation of the head 3 from the track center is very large, C or D becomes maximum, so the off-track OT is calculated from the array pitch of AB and the track. If the servo information SI is defective, the off-track OT cannot be calculated normally.

In this embodiment, in the next step S45, it is judged whether the track number TN read in the previous step is correct or not by being equal to the value of the variable j. If no, the flow is skipped to step S47, but if yes, the operation of step S46 is started. This step S46 is a step of detecting a defect of the servo information SI. In the illustrated example, the off-track TN calculated in the previous step is within a normal range or not, and a defect is detected depending on whether or not it can be calculated. .. The determination at this time is not limited to this, of course, and can be made based on, for example, whether or not all of the servo values A to D are within a normal range, or whether or not two or more of them are not 0 at the same time. Step S45
Alternatively, if the determination result in S46 is negative, the operation is step S47.
Enter the sector number variable j at that time as defect number jd
Value is stored and a flag F indicating that a defect is detected is set to 1.

The judgment results of steps S45 and S46 are, of course, usually the same, and the operation proceeds to step S48 to judge whether or not the off-track OT is smaller than the allowable limit δ. If step S50 is not entered, a head position correction command is issued in step S49. This can be achieved by slightly changing the value of the control command CS given to the drive circuit 5a so as to eliminate the off-track OT. The operation after step S49 and step S47 described above proceeds to step S50, and it is determined whether or not the variable j is smaller than its maximum value jm. As long as it is small, the variable j is advanced by one in step S51. The flow returns to step S43 and the same operation is repeated.

The above operation from step S43 to step S51 is repeated, and the sector number variable j reaches the maximum value jm when all the track numbers TN in the track Tj and the presence / absence of the servo information SI have been checked. , The flow exits this operation loop from step S50 and moves to step S52. In this step S52, whether or not a defect is detected in the track Tj is checked by checking whether the flag F is 0 or not, that is, if there is no defect, the operation proceeds to step S54.
If not, that is, if there is a defect, step S53 for excluding the sectors susceptible to the influence is entered.

The servo information verification means 40 is shown in FIG.
It is advisable to set the sector management table 41 in the storage area of the control processor 10 in association with this, and rewrite the contents each time the sector is replaced. Therefore, in this step S53, the sector management table 41 is first modified so that the spare sector replaces the sector corresponding to the defect number jd stored as described above for the track Tj. This sector to be replaced may be the sector before and after the servo information SI in which the defect is detected for safety, but it is usually the sector next to the defect. In this embodiment, since the defect number jd is the sector number to be replaced in the latter case, the defect number jd is notified to the formatting data editing means 60 via the communication bus 14 in order to prepare for the subsequent operation. The flag F and the defect number jd are set back to 0.

After step S53 or step S52
If the determination is YES, the operation proceeds to step S54, and an editing / writing command is given to the formatting data editing means 60 to activate the formatting operation. The formatting data editing means 60 edits the formatting data for one track in which the collation code ID including the sector number is written in each sector S of FIG. 1 (c) and stores it in the RAM 21 of the data processor 20. If the defect number jd is not notified, the normal formatting data is used.If the defect number is notified, the sector of the corresponding number is replaced with the spare sector, but the formatting data with a consistent sector number in the track is added. Are edited respectively. Writing to the track Tj is performed by the data processor 20 from the encoder, as described above.
The write signal WS may be given to the read / write circuit 6 via the decoder circuit 9.

On the servo information detecting means 40 side, the operation proceeds to step S55, and it is judged whether or not the track number variable i is smaller than its maximum value im, and if it is small, the variable i is stepped up in the next step S56. The flow returns to step S42 and the same operation is repeated for the next track. After the formatting of all the tracks in the disc is completed, the flow exits the loop from step S55 and the whole operation is completed.

Although the first formatting for the disk 1 is completed by the above, the reliability of the read / write operation can be maintained at a high level by executing the method of the present invention at any time during the use of the disk storage device, for example, every certain usage period thereafter. Can be maintained at. The operation at the time of reformatting may be the same as that in FIG. 2, but it is not necessary to perform reformatting on a track for which no defect is detected in the servo information, so if the determination in step S52 in FIG. 2 is correct. It is preferable to move the operation to step S55 as shown by the broken line in the figure. Further, the method of the present invention can be performed during read / write operations of the disk storage device. However,
In this case, since the target track is determined, the servo information detecting means 40 may be caused to perform an operation excluding the flow in the leftmost column in FIG. In this case as well, if the determination in step S52 is correct, the operation is of course completed. As described above, the method of the present invention can be implemented in various modes to improve the reliability of data reading / writing of the disk storage device.

[0030]

As described above, in the formatting method according to the present invention, the servo information verifying means is incorporated in the disk storage device of the inter-sector servo system, and the servo information is read from the disk surface by the servo information reading circuit so that each servo information is recorded. In addition to verifying the presence or absence of a defect, if there is a defect, the position within that track is detected, and based on this verification result, the formatting data editing means excludes the sector adjacent to the defective servo information and pre-writes in each track. The following effects can be achieved by having the set spare sector substitute the formatting data for editing and writing it in the track.

(A) Since the disk storage device is operated in a state in which the sectors that may interfere with reading and writing due to defective servo information are excluded, the heads in which data is irregular are also recorded in the sectors in the disk. There is no possibility of writing at a position, an error can be prevented, and the reliability of the read / write operation of the disk storage device can be maintained at a much higher level than before. (b) By performing the method of the present invention not only at the time of initial formatting, but also periodically during the period of use of the disk storage device or during its read / write operation, there is a possibility that defective servo information may interfere with read / write. The exclusion of a sector can be made more complete to further enhance the reliability of its read and write operations. (c) The method of the present invention can be easily implemented without substantial cost increase by loading the servo information verifying means in the disk storage device as its simple software and slightly changing the software for the formatting data editing means. it can.

As described above, the method of the present invention has the effect that the reliability of the read / write operation of the disk storage device can be guaranteed over the long period of use, and the data recording density can be increased to further increase the storage capacity. It can also contribute to the increase.

[Brief description of drawings]

FIG. 1 shows an embodiment of a formatting method according to the present invention, and FIG. 1 (a) is a configuration circuit diagram showing an example of the configuration of a disk storage device implementing the method of the present invention together with an outline of a mechanical section,
FIG. 2B is a partially developed view of the track of the inter-sector servo system, and FIG. 1C is a partially enlarged view of the same FIG. 2B showing a servo information writing procedure and a sector setting procedure.

FIG. 2 is a flowchart showing the overall operation of the method of the present invention corresponding to the embodiment of FIG. 1, focusing on the operation of the servo information verification means.

[Explanation of symbols]

 1 disk 3 head 10 control processor 20 data processor 30 servo information reading circuit 40 servo information verification means 41 sector management table 60 formatting data editing means S sector SI servo information T track TN track number attached to servo information

Claims (5)

[Claims] 1. A method of formatting a disk storage device in which servo information for detecting a head position is written between sectors as a recording unit of data.
Servo information reading circuit for reading servo information from the disk via the head, servo information verification means for receiving the servo information read by the servo information reading circuit and verifying the presence or absence of the defect and detecting the position of the defect, and one track In addition to providing a means for editing the formatting data of, the spare sector is set in each track and the spare sector replaces the sector adjacent to the defective position of the servo information based on the verification result of the servo information verification means. A formatting method for a disk storage device, characterized in that it is written in a track by being edited by a formatting data editing means. 2. The method according to claim 1, wherein the servo information verifying means verifies the presence or absence of a defect in the servo information while correcting the head position based on the servo information read by the servo information reading circuit. Disk storage device formatting method. 3. The disk storage device according to claim 1, wherein the track number is written along with the servo information, and the servo information verifying means verifies the presence or absence of a defect including the track number. Formatting method. 4. The method according to claim 1, wherein the servo information verifying means is activated while the disk storage device is in use, and the formatting data editing means is operated only for a track in which a servo information defect is detected. A method for formatting a disk storage device, comprising: 5. The method according to claim 1, wherein the servo information verifying means verifies the presence or absence of a servo information defect with respect to a track in which data is being read or written when the disk storage device is used, and when there is a defect, formatting data editing means. A method for formatting a disk storage device, characterized in that the disk drive is made to operate on the track.