JP2010225196A - Storage device, method of controlling the same, and electronic device using the storage device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a storage device capable of suppressing data read delay and a method of controlling the same, and an electronic device using the storage device. <P>SOLUTION: The storage device includes a head position control unit 40 which controls so that a head 12 for reading data recorded on a data track 20 of a magnetic disk 10 as a recording medium is on-track on the target data track 20, an on-track determination unit 42 which determines whether the head 12 is on-track on the target data track 20, and a read control unit 48 which reads data from the target data track 20 and complements a sector where data can not be read therefrom by dummy data even when the head 12 is not on-track on the target data track 20. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a storage device, a control method thereof, and an electronic device using the storage device.

  2. Description of the Related Art Recently, a hard disk drive (HDD) is installed in various products such as a personal computer, a navigation device, and an AV (Audio Visual) device. For this reason, there are increasing opportunities to be used for recording and reproducing video data and music data.

  Even if video data and music data may be lost to some extent, it does not pose a major problem when playing back video and music. For this reason, recent HDDs are equipped with a function for continuously transferring data without performing error recovery processing even if a data error (read error) occurs when reading video data or music data. There is something.

  In addition, a method has been proposed in which the data reading speed is not performed in real time in the same manner as the normal reproduction speed, the data is read at a high speed, and the read data is temporarily stored in a memory and then transferred ( For example, Patent Document 1). Thereby, even when a read error occurs, data can be transferred continuously.

  A method has also been proposed in which data can be transferred continuously even if the memory overflows due to the difference between the data storage speed in the memory and the data transfer speed from the memory (for example, Patent Document 2).

JP-A-2005-78760 JP 2008-176926 A

  Conventionally, in response to a read request from the host, if the head is not on-tracked to the target data track due to residual vibration, disturbance, etc., a recovery process that seeks the head to the target data track again and attempts on-track is performed again. It has been broken.

  This recovery process will be described with reference to FIG. As shown in FIG. 1A, in response to a read request related to a plurality of sectors from the host, the head is sought to the target data track and on-track is attempted. At this time, due to residual vibration, disturbance, or the like, on-track may not be performed at the head sector in the read request range, but may be on-track at an intermediate sector (for example, the fourth sector from the head sector). In this case, as shown in FIG. 1B, the on-track is tried again so that it is on-tracked at the head sector. After successful on-track in the first sector, a data read operation is executed from the first sector, and the read data is transferred to the host.

  When the recovery process as shown in FIG. 1 is performed, a disk rotation wait occurs, which causes a delay in data reading. While data reading is delayed, data is not transferred to the host, and data transfer is interrupted.

  Patent Documents 1 and 2 do not disclose a technique for solving such a problem related to on-track recovery processing.

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a storage device capable of suppressing delay in reading data, a control method thereof, and an electronic device using the storage device. To do.

  The storage device described in this specification includes a head position control unit that controls a head that reads data recorded on a data track of a recording medium to be on-tracked to a target data track, and the head is turned on to the target data track. Even if the head is not on-tracked to the target data track, data is read from the target data track, and dummy data is read for a sector from which data cannot be read. And a complementary lead control unit.

  According to this, even when the data is not on-track to the target data track, the data is read, and the dummy data is supplemented for the sector where the data cannot be read, thereby eliminating the on-track recovery process and the data read-out. Delay can be suppressed. Therefore, data can be transferred continuously.

  The storage device control method described in this specification includes a head position control process in which a head that reads data recorded on a data track of a recording medium is controlled to be on-track to a target data track; On-track determination process for determining whether or not the track is on-track, and even if the head is not on-track to the target data track, data is read from the target data track, and the sector from which data cannot be read A read control process for complementing the dummy data.

  According to this, even when the data is not on-track to the target data track, the data is read, and the dummy data is supplemented for the sector where the data cannot be read, thereby eliminating the on-track recovery process and the data read-out. Delay can be suppressed. Therefore, data can be transferred continuously.

  The electronic device described in this specification includes the storage device described in this specification.

  According to this, the delay of data reading is suppressed, and the provision of the storage device capable of continuously transferring data can suppress the interruption of video and music playback in the middle.

  According to the storage device and the control method thereof described in the present specification, it is possible to suppress a data read delay, and it is possible to transfer data continuously. In addition, according to the electronic device described in the present specification, there is an effect that it is possible to prevent the reproduction of video and music from being interrupted.

FIG. 1 is a diagram for explaining on-track recovery processing. FIG. 2 is a block diagram for explaining the configuration of the storage device according to the first and second embodiments. FIG. 3 is a diagram for explaining data tracks and servo patterns formed on the magnetic disk. FIG. 4 is a functional block diagram of the MPU of the storage device according to the first and second embodiments. FIG. 5 is a flowchart (part 1) for explaining the read operation of the storage device according to the first embodiment. FIG. 6 is a flowchart (part 2) illustrating the read operation of the storage device according to the first embodiment. FIG. 7 is a diagram (part 1) for explaining the read operation of the storage device according to the first embodiment. FIG. 8 is a diagram (part 2) for explaining the read operation of the memory device according to the first embodiment. FIG. 9 is a flowchart (part 1) for explaining the read operation of the storage device according to the second embodiment. FIG. 10 is a flowchart (part 2) illustrating the read operation of the storage device according to the second embodiment. FIG. 11 is a diagram for explaining the read operation of the storage device according to the second embodiment. FIG. 12 is a block diagram for explaining a configuration of an electronic device including the storage device according to the first embodiment or the second embodiment.

  Hereinafter, a magnetic disk device 100 as an embodiment of the storage device of the present invention will be described.

  FIG. 2 is a block diagram of the magnetic disk device 100 according to the first embodiment. As shown in FIG. 2, the magnetic disk device 100 includes a control board 90 and a disk enclosure 80.

  The disk enclosure 80 includes a magnetic disk 10 as a recording medium, a head 12, a head amplifier 14, a voice coil motor 16, and a spindle motor 18.

  The magnetic disk 10 is a recording medium for recording data by changing the magnetization state of the applied magnetic material. As shown in FIG. 3, a data track 20 on which user data is recorded and servo information are recorded. The servo pattern 22 is formed on the surface of the magnetic disk 10. A plurality of data tracks 20 are formed concentrically along the circumferential direction of the magnetic disk 10, and each data track 20 is divided into a plurality of sectors. A plurality of servo patterns 22 are formed radially in the radial direction of the magnetic disk 10 and have servo information of track data, sector data, and burst data. The track data has a data track number written therein, and the sector data has a sector number written therein. The burst data has relative position information of the head 12 with respect to the data track 20 and is used to accurately position the head 12 at the center of the target data track 20.

  Returning to FIG. 2, the head 12 is a main body made of ceramic or the like, and a recording element for writing and erasing data on the magnetic disk 10, and for reading data and servo information written on the magnetic disk 10. And a reproducing element.

  The head amplifier 14 includes a reproduction amplifier for amplifying a read signal read from the head 12 (reproduction element) and a recording amplifier for amplifying a write signal supplied to the head 12 (recording element).

  The voice coil motor 16 drives a head stack assembly (HSA) that holds the head 12 under the control of the servo controller 32, and moves (seeks) the head 12 in the radial direction of the magnetic disk 10. The head 12 is positioned on the data track 20.

  The spindle motor 18 rotates the magnetic disk 10 at an appropriate rotation speed such as 4200 to 15000 rpm under the control of the servo controller 32.

  The control board 90 includes a read / write channel 24, a hard disk controller (HDC) 26, a data buffer 28, a memory 30, a servo controller 32, and an MPU (Micro Processing Unit) 34. These are connected to each other by a system bus 36.

  The read / write channel 24 processes read / write signals related to recording / reproducing operations.

  The HDC 26 controls transmission and reception of various commands and data with the host 38. Further, the HDC 26 determines a read error based on an instruction from the MPU 34. The data buffer 28 temporarily stores write data input from the host 38 and read data read from the magnetic disk 10.

  The memory 30 includes, for example, a volatile memory such as a RAM (Random Access Memory) and a non-volatile memory such as a flash ROM (Read Only Memory). The RAM is a work memory used when the MPU 34 executes control processing. The flash ROM stores a control program executed by the MPU 34 in advance.

  The servo controller 32 controls the voice coil motor 16 and the spindle motor 18 based on instructions from the MPU 34.

  The MPU 34 performs overall control of the magnetic disk device 100 such as read / write operation control, head 12 positioning control, and read data error determination control read from the magnetic disk 10. As shown in FIG. 4, the MPU 34 includes a head position control unit 40, an on-track determination unit 42, a read continuation function determination unit 44, a retry count determination unit 46, a read control unit 48, and a read error determination control unit 50. ing. These are connected to each other by the system bus 52 and executed when the MPU 34 reads out a control program stored in advance in the flash ROM of the memory 30.

  The head position control unit 40 uses the servo information recorded in the servo pattern 22 to control the servo controller 32 to seek the head 12 to the target data track 20 according to the read request from the host 38 and to perform on-track. Process.

  The on-track determination unit 42 determines whether or not the head 12 is on-tracked on the target data track 20. For example, the positional deviation amount of the head 12 is calculated from the amplitude of the signal obtained by the head 12 reading the burst data of the servo pattern 22, and the on-track is determined depending on whether the positional deviation amount is within a predetermined range. Determine success or failure.

  The lead continuation function determination unit 44 determines whether the lead continuation function is ON or OFF. For example, the read continuation function can be set to ON when the data that is the target of the read request from the host 38 is video data or music data, and can be set to OFF when the data is information processing data.

  The retry number determination unit 46 determines whether the number of seeks of the head 12 to the target data track 20 has reached a specified number, and whether the number of reads of data from the same sector has reached a specified number.

  The read control unit 48 reads data recorded in the sector. Further, when the read error determination control unit 50 described later determines that an error has occurred in the read data read from the sector, for example, dummy data is supplemented as the data of the sector.

  The read error determination control unit 50 controls the HDC 26 to determine whether an error has occurred in the read data read from the sector.

  Next, a read operation in response to a read request from the host 38 will be described using the flowcharts of FIGS. As shown in FIG. 5, when the MPU 34 receives a read request for data relating to a plurality of sectors from the host 38 (step S10), the MPU 34 controls the servo controller 32 to drive the voice coil motor 16 and the spindle motor 18 to respond to the read request. The head 12 is sought to the corresponding target data track 20 (step S12). At this time, the servo information recorded in the servo pattern 22 is used.

  Next, the MPU 34 tries to on-track the head 12 to the target data track 20 using the burst data recorded in the servo pattern 22, and determines whether the on-track is successful (step S14). When residual vibration or disturbance occurs, on-track may fail. Whether the on-track is successful or not can be determined based on whether or not the positional deviation amount of the head 12 calculated from the amplitude of the signal obtained from the burst data is within a predetermined range.

  When the on-track fails (in the case of No), the MPU 34 first determines whether the read continuation function is ON or OFF (step S16). ON / OFF of the read continuation function can be switched depending on whether the data related to the read request from the host 38 is video data, music data, or information processing data.

  When the read continuation function is OFF (in the case of No), since the data related to the read request from the host 38 is information processing data, the lack of data is not allowed, so the MPU 34 again performs seek and on-track. Try. Specifically, first, the MPU 34 determines whether the number of seeks to the target data track 20 has reached the specified number of seek retries (step S18). When the specified number of times has not been reached (in the case of No), the MPU 34 again seeks the head 12 to the target data track 20 (step S20) and tries on-track (step S14). When the specified number of times has been reached (in the case of Yes), it is considered that seek to the target data track 20 and on-track cannot be performed due to various factors such as a failure of the head 12, so the MPU 34 performs seek error processing. The seek to the target data track 20 is stopped (step S22).

  When the read continuation function is ON (in the case of Yes), the data related to the read request from the host 38 is video data or music data, and therefore some data loss is permitted. Therefore, as shown in FIG. 6, the MPU 34 does not perform the on-track recovery process to the target data track 20 (step S24), and performs a data read operation from the first sector in the read request range (step S26). In the read operation, the read signal read by the head 12 is signal-processed by the read / write channel 24 and sent to the HDC 26.

  Next, the MPU 34 controls the HDC 26 to determine whether or not an error has occurred in the read data that has been read (step S28). When residual vibration or disturbance continues to occur, data cannot be normally read from the sector, and a read error occurs. If a read error has occurred (in the case of Yes), the MPU 34 determines whether the sector that has performed the read operation is the first sector in the read request range (step S30). If it is the head sector (Yes), the MPU 34 supplements the dummy data as the data of the head sector and stores it in the data buffer 28 (step S32). If it is not the first sector (in the case of No), the MPU 34 supplements the same data as the data of the sector immediately before the sector on which the read operation is performed as data of the sector, and stores it in the data buffer 28 (step S34). . That is, when dummy data is supplemented in the previous sector, dummy data is also supplemented for the sector on which the read operation has been performed and stored in the data buffer 28. Further, when the read data actually read in the previous sector is stored in the data buffer 28, the read data of the previous sector is complemented and stored in the data buffer 28 for the sector. To do.

  In step S28, if residual vibration, disturbance, etc. are settled and data can be normally read from the sector, and no read error has occurred (in the case of No), the MPU 34 converts the read data actually read into the data The data is stored in the buffer 28 (step S36).

  Next, the MPU 34 determines whether or not the read operation has been completed for all sectors in the read request range from the host 38 (step S38). If the read operation has not been completed for all sectors (in the case of No), the MPU 34 performs the read operation for the next sector (step S40), and executes the processes described in steps S28 to S36.

  If the read operation has been completed for all sectors (Yes), the MPU 34 transfers the data stored in the data buffer 28 to the host 38 (step S42).

  Returning to FIG. 5, if it is determined in step S14 that the on-track has succeeded (in the case of Yes), the MPU 34 performs a data read operation from the first sector in the read request range (step S44).

  Next, the MPU 34 determines whether an error has occurred in the read data that has been read (step S46). If no read error has occurred in all sectors in the read request range (in the case of No), the MPU 34 transfers the read data actually read to the host 38 via the data buffer 28 (step). S48).

  If a read error has occurred (Yes), the MPU 34 determines whether the read continuation function is ON or OFF (Step S50). When the read continuation function is ON (in the case of Yes), as described above, the read data relates to video data or music data, and some data loss is permitted. Therefore, the MPU 34 stores dummy data in the data buffer 28 without executing the read operation again for the sector in which the read error has occurred. For a sector in which no read error has occurred, the read data that is actually read is stored in the data buffer 28, and after the read operation is completed for all sectors in the read request range, the read data is stored in the data buffer 28. The transferred data is transferred to the host 38 (step S52).

  When the read continuation function is OFF (in the case of No), as described above, the read data relates to information processing data, and data loss is not allowed. For this reason, the read operation is repeated again. Specifically, the MPU 34 first determines whether the number of read operations for the same sector has reached the specified number of read retries (step S54). If the specified number of times has not been reached (No), the MPU 34 executes the read operation again (step S56). If the specified number of times has been reached (Yes), read error processing is performed and the read operation is stopped (step S58).

  Next, with reference to FIG. 7, the process of the steps shown in steps S24 to S42 in FIG. 6 will be described by taking as an example the case where the MPU 34 receives a read request relating to 9 sectors from the host 38.

  As shown in FIG. 7, when the head 12 is sought to the target data track 20 in response to a read request from the host 38 and an on-track is attempted, the head 12 is turned on at the head sector of the read request range due to residual vibration or disturbance. Sometimes you can't track. At this time, when the data related to the read request from the host 38 is video data or music data, the read operation is executed from the head sector without performing the on-track recovery process to the head sector. For example, from the first sector to the third sector, the effects of residual vibration, disturbance, etc. remain, and if on-tracking is not possible and an error occurs in the read data, dummy data is used as the third sector data from the first sector. Are stored in the data buffer 28. For example, in the fourth sector, when residual vibration, disturbance, etc. are settled and on-tracking is possible, read data is stored in the data buffer 28. Then, after the read operation is completed for all nine sectors, the data stored in the data buffer 28 is transferred to the host 38.

  As described above, according to the first embodiment, even when the head 12 is not on-tracked to the target data track 20 corresponding to the read request from the host 38, data is read from the head sector in the read request range. . For a sector in which read data has an error and data cannot be read normally, the dummy data is complemented and transferred to the host 38. For the sector from which data has been normally read, the read data is transferred to the host 38.

  As a result, even when the target data track 20 is not on-track, the on-track recovery process is eliminated, and the occurrence of a data read delay due to waiting for rotation of the magnetic disk 10 in the recovery process can be suppressed. Therefore, data can be transferred to the host 38 continuously.

  The data transferred to the host 38 is a mixture of read data and dummy data. However, as described above, even if there is a certain amount of data missing, there is little influence on video data and music data. In other words, when the data read from the data track 20 is video data or music data, even if the read data and dummy data are mixed, the video data and music data are continuously displayed without affecting the reproduced video and music. Can be processed.

  Further, as described in steps S30 to S34 in FIG. 6, when an error occurs in the read data and the sector from which data cannot be normally read is the head sector of the read request range, the dummy data is supplemented. If the sector from which data cannot be read normally is not the first sector, the same data as that of the previous sector is complemented. As a result, for example, when data is normally read in the sector immediately before the sector in which the read error has occurred, the data is highly related to the original data of the sector in which the read error has occurred instead of dummy data. The data of the previous sector is complemented, and the influence on the reproduced video and music can be further suppressed.

  Further, as shown in FIG. 8, even when a so-called head switch is generated in which a sector related to a read request range from the host 38 extends over different data tracks 20, the flowcharts of FIGS. 5 and 6 can be used. That is, even when the target data track 20 after the head switch cannot be on-tracked due to residual vibration or disturbance caused by the head switch, the on-track recovery process is eliminated by executing the flowcharts of FIGS. Occurrence of data read delay can be suppressed. Therefore, data can be transferred to the host 38 continuously.

  The block diagram of the magnetic disk device according to the second embodiment is the same as the block diagram of the magnetic disk device 100 according to the first embodiment and is shown in FIG. Further, in the MPU 34 included in the magnetic disk device according to the second embodiment, when the on-track determination unit 42 has the read continuation function ON, the on-track determination criterion is set loosely and the on-track success / failure determination is performed. Except for this point, the second embodiment is the same as the first embodiment and is shown in FIG.

  Next, a read operation in response to a read request from the host 38 will be described using the flowcharts of FIGS. 9 and 10. As shown in FIG. 9, when the MPU 34 receives a read request for data related to a plurality of sectors from the host 38 (step S60), it first determines whether the read continuation function is ON or OFF (step S62). .

  When the read continuation function is OFF (in the case of No), the MPU 34 seeks the head 12 to the target data track 20 according to the read request (step S64), attempts to perform on-track, and checks whether the on-track is successful. Determination is made (step S66). As described above, the success / failure of the on-track can be determined by the positional deviation amount of the head 12 calculated from the amplitude of the signal obtained from the burst data. Here, when the read continuation function is OFF, the data related to the read request from the host 38 is information processing data, and therefore data loss is not allowed. Therefore, the allowable range of the positional deviation amount of the head 12, which is a reference value for determining success or failure of on-track, is set narrow as usual.

  When the on-track has failed (in the case of No), the MPU 34 again performs seek and on-track to the target data track 20 in the same manner as the steps described in steps S18 to S22 of FIG. Try. Specifically, the MPU 34 determines whether or not the number of seeks has reached the specified number (step S68). If not reached (in the case of No), the MPU 34 causes the head 12 to seek the target data track 20 (step S68). S70), on-track is attempted (step S66). When the specified number of times has been reached (in the case of Yes), the MPU 34 performs seek error processing and stops seeking (step S72).

  When it is determined that the on-track has succeeded (in the case of Yes), the MPU 34 performs a data read operation from the first sector in the read request range (step S74), and no error has occurred in the read data that has been read. (Step S76). If no error has occurred in the read data for all sectors in the read request range (No), the read data is transferred to the host 38 via the data buffer 28 (step S78).

  When an error has occurred in the read data (in the case of Yes), the MPU 34 executes the read operation again in the same manner as the steps described in steps S54 to S58 in FIG. Specifically, the MPU 34 determines whether the number of read operations has reached the specified number (step S80). If the number has not reached (No), the read operation is performed again on the sector in which the read error has occurred. Is executed (step S82). If the specified number of times has been reached (Yes), read error processing is performed and the read operation is stopped (step S84).

  If it is determined in step S62 that the read continuation function is ON (in the case of Yes), the data related to the read request from the host 38 is video data or music data, and therefore some data is missing. Is not so much of a problem. Therefore, the MPU 34 loosely sets a determination criterion for determining success or failure of on-track (step S86). Specifically, the allowable range of the positional deviation amount of the head 12 calculated from the amplitude of the signal obtained from the burst data is increased.

  Thereafter, the MPU 34 seeks the head 12 to the target data track 20 corresponding to the read request (step S88), and tries to perform on-track. Here, since the on-track success / failure criteria are loosely changed, it is usually determined that the on-track has succeeded even if the positional deviation amount of the head 12 is determined to have failed. Will come to be.

  Thereafter, the flowchart of FIG. 10 is executed. The steps from step S90 to step S106 shown in the flowchart of FIG. 10 are the same as the steps from step S26 to step S42 shown in FIG. 6 of the first embodiment, and thus description of the processing of each step is omitted.

  Next, with reference to FIG. 11, the process of the steps shown in steps S86 to S106 in FIGS. 9 and 10 will be described using the case where the MPU 34 receives a read request for 9 sectors from the host 38 as an example.

  As shown in FIG. 11, when a read request related to video data or music data is received from the host 38, the on-track determination criterion is relaxed by increasing the allowable range of the positional deviation amount of the head 12. As a result, it is determined that the on-track has succeeded without being affected even if there is some residual vibration or disturbance. However, in this case, not the target data track 20 but, for example, a case where it is on-track to the adjacent data track 20 may occur. Thereafter, data is read from the data track 20 that is on-track, and if there is no error in the read data that has been read, the read data is stored in the data buffer 28. Then, after the read operation is completed for all nine sectors, the data stored in the data buffer 28 is transferred to the host 38.

  As described above, according to the second embodiment, the tolerance of the positional deviation amount of the head 12, which is a determination criterion for determining the success / failure of on-track, is increased, and the determination criterion is set loosely to determine the success / failure of on-track. This makes it easy to determine that the on-track has succeeded regardless of the effects of residual vibration, disturbance, etc., and eliminates the on-track recovery process. For this reason, it is possible to suppress occurrence of a data read delay due to waiting for rotation of the magnetic disk 10 in the recovery process.

  In addition, by relaxing the on-track success / failure determination criteria, there may be a case where, for example, the adjacent data track 20 is on-track instead of the target data track 20. However, as described above, video data and music data will not be a big problem even if data is lost to some extent, so that even if the data of the adjacent data track 20 is transferred to the host 38 to some extent, it is reproduced. Video and music are not affected much.

  FIG. 12 is a block diagram of an electronic device 200 including the magnetic disk device 100 according to the first or second embodiment. Examples of the electronic device 200 include electronic devices that store data such as telephones, audio machines, personal computers, HDD recorders, and the like. In particular, electronic devices used for video and music reproduction are preferable.

  As illustrated in FIG. 12, the electronic device 200 includes a magnetic disk device 100, a controller (CPU) 202, and an interface 204. The magnetic disk device 100, the controller 202, and the interface 204 are connected by a system bus 206.

  The interface 204 exchanges data with the outside. The controller 202 controls various commands and the like with the HDC 26 in the magnetic disk device 100. For example, the HDC 26 is instructed so that data input from the outside via the interface 204 is recorded on the magnetic disk 10 in the magnetic disk device 100. Further, the controller 202 instructs the HDC 26 to read the data recorded on the magnetic disk 10 and outputs the read data to the outside via the interface 204.

  As described above, the magnetic disk device 100 according to the first embodiment or the second embodiment can continuously transmit data to the interface 204 even if residual vibration or disturbance occurs. For this reason, for example, when the electronic device 200 is an electronic device used for reproducing video and music, the video and music can be continuously reproduced without interruption.

  The embodiment described above is a preferred embodiment of the present invention. However, the present invention is not limited to this, and various modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 10 Magnetic disk 12 Head 14 Head amplifier 16 Voice coil motor 18 Spindle motor 20 Data track 22 Servo pattern 24 Read / write channel 26 Hard disk controller 28 Data buffer 30 Memory 32 Servo controller 34 MPU
38 host 40 head position control unit 42 on-track determination unit 44 read continuation function determination unit 46 retry count determination unit 48 read control unit 50 read error determination control unit 80 disk enclosure 90 control board 100 magnetic disk device 200 electronic device 202 controller (CPU) )
204 interface

Claims (5)

A head position controller that controls the head that reads data recorded on the data track of the recording medium to be on-track to the target data track;
An on-track determination unit for determining whether the head is on-tracked to the target data track;
Even when the head is not on-track to the target data track, a read control unit that reads data from the target data track and supplements dummy data for sectors where data cannot be read;
A storage device comprising:   The storage device according to claim 1, wherein the on-track determining unit sets a criterion for determining whether or not the data track is on-track, and determines whether or not the head is on-tracked to the target data track. .   The read control unit supplements dummy data when the sector from which data cannot be read is the first sector of the read range, and supplements the same data as the data of the previous sector when the sector is not the first sector. The storage device according to claim 1 or 2. A head position control step for controlling a head for reading data recorded on a data track of a recording medium to be on-track to a target data track;
An on-track determination step of determining whether the head is on-tracked to the target data track;
A read control step of reading data from the target data track even when the head is not on-track to the target data track, and supplementing dummy data for sectors where data cannot be read; and
A method for controlling a storage device, comprising:   An electronic device comprising the storage device according to claim 1.

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