JP2010044820A - Recorder and recording method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recorder and a recording method for efficiently rewriting data. <P>SOLUTION: The recorder includes: a magnetic disk 101 in which a storage area where data is written is provided; a magnetic head 102 for writing data into each storage section classified from the storage area and reading the data from the storage sections; a determination means 115 for determining whether a sequential writing is carried out, which writes the data into each storage section in order of physical address; a writing frequency management means 115 for counting the writing frequency in which the writing to the same storage section is repeated and also for returning the writing frequency of the storage section, which is determined by the determination means as the sequential writing is carried out, to an initial value; and a refresh means 115 for referring to the writing frequency and newly rewriting the data stored in the storage section by using the magnetic head. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a recording apparatus and a recording method.

  In recent years, disk devices that store stream data such as computer data and digital video data have become widespread. In these disk devices, a plurality of tracks (cylinders) are concentrically formed on a disk medium as a recording medium. Each track is divided into a plurality of data sectors, and data read / write access is executed in units of sectors.

  In addition, in these disk apparatuses, there is an apparatus designed to increase the density by narrowing the interval (track pitch) between adjacent tracks in order to increase the recording capacity. However, if the track pitch is narrowed, new data may be overwritten on the past data in the vicinity of the boundary between adjacent tracks, and the past data may not be read.

Some of these disk devices have a refresh function of periodically reading past data and rewriting the data. For example, Patent Document 1 discloses an apparatus having a function of recording the number of times data has been written on a track, and reading and rewriting a track adjacent to the track that has reached a specified number.
JP 2004-273060 A

  However, the apparatus disclosed in Patent Document 1 does not consider performing refresh processing by distinguishing between storage areas in which data is sequentially written and storage areas in which data is not sequentially written. Therefore, there is a possibility that past data is rewritten to a storage area that does not require refresh processing.

  SUMMARY An advantage of some aspects of the invention is that it provides a recording apparatus and a recording method capable of efficiently rewriting data.

  In order to solve the above-described problems, the present invention provides a magnetic disk provided with a storage area in which data is written, data writing to each storage area partitioned from the storage area, and data reading from each storage area. And a determination means for determining whether or not sequential writing for writing data to the storage areas in the order of physical addresses is performed, and the number of times of repeated writing to the same storage area is counted and the determination is made Means for returning to the initial value the number of writes of the storage section determined to have been sequentially written by the means, and data stored in the storage section using the magnetic head with reference to the write count And a refresh means for rewriting a new one.

  The present invention also relates to a recording method for rewriting data written in a storage area, in which sequential writing is performed in which data is written in order of physical addresses to a plurality of storage areas in which the storage area of the magnetic disk is divided. And determining the number of times of writing in the storage area where the data writing is duplicated, and returning the number of times of writing in the storage area determined to have been sequentially written by the determination means to an initial value, With reference to the number of times of writing, the data written in the storage area is newly rewritten using a magnetic head.

  According to the present invention, it is possible to provide a recording apparatus that can efficiently rewrite data.

Embodiments of the present invention will be described below with reference to the drawings.
First, the configuration of the recording apparatus of this embodiment will be described with reference to FIGS. FIG. 1 is a block diagram showing a configuration of a recording apparatus according to an embodiment of the present invention. FIG. 2 is a conceptual diagram showing a format including the track arrangement of the disc. FIG. 3 is a diagram illustrating an example of the data structure of the track management table 300 according to the present embodiment.

  As shown in FIG. 1, the recording apparatus of this embodiment is an apparatus such as a magnetic disk drive (HDD) 100, for example. The HDD 100 is a storage device that executes writing of data on the recording surface of the disk (magnetic disk) 101 and reading of data from the recording surface in response to a request from the host system 200. The host system 200 is an electronic device such as a personal computer that uses the HDD 100 as a storage device.

  The disk 101 is fixed to a spindle motor (SPM) 103, and rotates at a constant speed when the SPM 103 is driven. For example, one disk surface of the disk 101 forms a recording surface on which data is magnetically recorded. A head (magnetic head) 102 is arranged corresponding to the recording surface of the disk 101.

  The head 102 is fixed to one end of an actuator 105, and the other end of the actuator 105 is fixed to a voice coil motor (VCM) 104. When the VCM 104 is driven, the head 102 moves in a range that overlaps the surface of the disk 101 in an arc trajectory centered on the axis of the VCM 104.

  In the configuration of FIG. 1, the HDD 100 including a single disk 101 is assumed. However, the configuration is not limited thereto, and a plurality of disks 101 are fixed to the SPM 103 with a gap. It doesn't matter. In this case, the plurality of actuators 105 are fixed to the VCM 104 in a state where they overlap with the gaps of the plurality of disks 101. A head 102 is fixed to one end of each of the plurality of actuators 105. Therefore, as the SPM 103 is driven, all the disks 101 rotate simultaneously, and as the VCM 104 is driven, all the heads 102 move simultaneously.

  In the configuration of FIG. 1, one surface of the disk 101 forms a recording surface. However, the present invention is not limited to this, and both surfaces of the disk 101 both form a recording surface, and the head 102 is arranged corresponding to each recording surface. It does not matter.

  Here, as shown in FIG. 2, a plurality of tracks 201 are concentrically arranged on the recording surface of the disk 101. Data received by the HDD 100 from the host system 200 is recorded on at least one of the plurality of tracks 201 in accordance with an address designated by the host system 200.

  Servo areas 202 and data areas 203 are alternately arranged at equal intervals on the plurality of tracks 201 of the disk 101. Servo signals used for positioning the head 102 are recorded in the servo area 202. The data area 203 is used for recording data transferred from the host system 200.

  Referring again to FIG. 1, the CPU 115 functions as a main controller of the HDD 100. The CPU 115 performs control for starting / stopping the SPM 103 and maintaining the rotation speed via the motor driver 106. The CPU 115 also controls to drive the VCM 104 via the motor driver 106 to move the head 102 to the target track and to set the head within the target range of the track.

  Control for moving the head 102 to the target track is called seek control, and control for setting the head 102 within the target range of the target track is called head positioning control. Further, the CPU 115 performs refresh control (refresh processing) for rewriting data written to the track 201 of the disk 101 again.

  Positioning of the head 102 is performed in a steady rotation state after the start of the SPM 103. Since the servo area 202 is arranged at equal intervals on the disk 101, the servo signal recorded in the servo area 202 is time-sequentially included in the analog signal read from the disk 101 by the head 102 and amplified by the head IC 107. Appear at regular intervals.

  The read / write IC 108 and the gate array 109 generate signals for positioning the head 102 by processing analog signals. The CPU 115 controls the motor driver 106 based on this signal to supply a current (VCM current) for positioning the head 102 from the motor driver 106 to the VCM 104 in real time.

  Further, the CPU 115 controls the SPM 103 and the VCM 104 via the motor driver 106, while executing control of other ICs, command processing, and the like to control the entire HDD. The CPU 115 is connected to the CPU bus 112. A read / write IC 108, a gate array 109, a disk controller (HDC) 110, a RAM 113, and a flash ROM 114 are connected to the CPU bus 112.

  The flash ROM 114 is a rewritable nonvolatile memory. Note that the flash ROM 114 is rewritten under the control of the CPU 115. The flash ROM 114 stores a program to be executed by the CPU 115 in advance. In addition, a part of the storage area of the flash ROM 114 stores a track management table 300 that manages information of each track, which will be described later, and a write count table that manages the number of writes for each allocated storage area.

  As shown in FIG. 3, for example, in this embodiment, data written in each track is managed in a table format. In the track management table 300, a logical address (LBA), a data size, a physical address at which writing is started, and link information are registered. The link information is attribute information indicating the correspondence between the physical address of the track and the logical block of the RAM 113. As described above, in this embodiment, by referring to the track management table 300, the logical address and the physical address can be associated with each other, and the write command from the host system 200 can be processed.

  Referring back to FIG. 1, the RAM 113 is used to store various variables used by the CPU 115, for example. A part of the storage area of the RAM 113 is used as a work area of the CPU 115.

  The read / write IC 108 includes a servo block 121 and a read / write block 122. The servo block 121 performs signal processing necessary for positioning of the head 102 including extraction of servo signals. The read / write block 122 performs signal processing for reading / writing data. The gate array 109 generates various control signals including a signal for extracting a servo signal by the servo block 121.

  In addition to the CPU bus 112, the HDC 110 is connected to the host system 200, the gate array 109, and the buffer RAM 111. The HDC 110 includes a host block 123, a read / write block 124, and a buffer block 125. The host block 123 has a host interface control function for receiving a command (write command, read command, etc.) transferred from the host system 200 and controlling data transfer between the host and the HDC 110. The read / write block 124 is connected to the read / write IC 108 and the gate array 109, and performs read / write processing of data performed via the read / write IC 108. The buffer block 125 controls the buffer RAM 111. A part of the storage area of the buffer RAM 111 is used as a write buffer for temporarily storing data (write data) written to the disk 101 via the HDC 110 (read / write block 124 in the HDC 110). Another part of the storage area of the buffer RAM 111 is used as a read buffer for temporarily storing data (read data) read from the disk 101 via the HDC 110.

  The read / write IC 108, the gate array 109, and the HDC 110 each have a control register. Each of these control registers is allocated to a part of the memory space of the CPU 115, and the CPU 115 accesses this part of the area, so that the read / write IC 108 and the gate array 109 are accessed via the control register. Or the HDC 110 is controlled.

  Next, data read processing in the HDD 100 of this embodiment will be described with reference to FIG. FIG. 4 is a flowchart showing the flow of data read processing in this embodiment.

  First, the CPU 115 of the HDD 100 reads an analog signal from the disk 101 using the head 102 in accordance with a data read command from the host system (S11). Next, the head IC 107 amplifies the read analog signal and outputs it to the read / write IC 108 (S12). The read / write IC 108 separates the signal received from the head IC 107 into a servo signal and a data signal, and outputs the data signal to the read / write block 122 (S13).

  The read / write block 122 in the read / write IC 108 decodes the data signal and sends it to the HDC 110 (S14). Next, the read / write block 124 in the HDC 110 processes the decoded data signal according to the control signal from the gate array 109 to generate data to be transferred to the host system 200 (S15).

  The buffer block 125 in the HDC 110 transfers the data generated in S15 to the host system 200 while temporarily storing the data in the buffer RAM 111 (S16).

  Next, a data writing process in the HDD 100 of this embodiment will be described with reference to FIG. FIG. 5 is a flowchart showing the flow of data writing processing in this embodiment.

  First, the CPU 115 of the HDD 100 receives the data read command and transfer data output from the host system at the host block 123 (S21). Next, the buffer block 125 in the HDC 110 takes out the transfer data while temporarily storing it in the buffer RAM 111, and outputs it to the read / write block 124 in the HDC 110.

  When data is received from the buffer block 125, the read / write block 124 in the HDC 110 refers to a control signal for positioning the head 102 generated by the gate array 109 and sends the data to the read / write IC 108. The read / write block 122 in the read / write IC 108 encodes the data received from the read / write block 124 in the HDC 110 and outputs it to the head 102 (S22). Finally, the head 102 writes the encoded data to the disk 101 under the control of the CPU 115 and ends the process (S23).

  Next, a sequential data write operation in the present embodiment will be described with reference to FIGS. FIG. 6 is a diagram showing a state in which data A and B are written in adjacent tracks on the disk 101. FIG. 7 is a diagram illustrating a state in which data is sequentially written from the adjacent track N + 1 on the disk 101 in order.

  Here, the state in which data is sequentially written in the present embodiment refers to a state in which data is written to adjacent tracks in the order of physical addresses in accordance with a write command. In the HDD 100 according to the present embodiment, for example, when a command for sequentially writing data is received from the host system 200, when stream data such as a TV program is written in an area of one track or more, or the LBA of the track in which the last writing has been completed lastly. Sequential write is considered to be executed in any case where writing is started from a track having continuous LBAs. Note that LBAs are assigned in order to sectors included in continuous tracks. Further, in this embodiment, as a method for finding the track that has been written last time, for example, a method of detecting the latest data updated last is adopted. If the latest data can be detected, the track storing the latest data can be found as the track in which the previous writing was finished last.

  As shown in FIG. 6, when data B is written to the adjacent track N + 2 after data A is written to the track N + 1 on the disk 101, the data portion on the track N + 2 side is overwritten in the recording data A. If such overwriting is repeated, the recording signal of the recording data A on track N + 1 is weakened, and there is a possibility that the reading operation becomes impossible.

  In addition, as shown in FIG. 7, when data is sequentially written from the track N + 1 on the disk 101, the data N + 1 to N + 3 overload each adjacent track on one side once when the data N + 4 is written. Lighted. That is, in the case of sequential writing only, the adjacent track on one side is overwritten only at most once, so that the risk of erasing the recording data signal is extremely low even when the track pitch is narrowed.

  Therefore, in this embodiment, the refresh process is executed by distinguishing between a storage area where data is sequentially written and a storage area where data is not written sequentially. As a result, the refresh process can be executed efficiently, reducing the power consumption and preventing the performance of the command from the host from being lowered.

  Next, with reference to FIG. 8, the determination of whether or not to perform the refresh process of the present embodiment will be specifically described. FIG. 8 is a diagram showing an example of the data structure of the write count table 400 that holds the number of writings for each track group. The write count table 400 is stored in a predetermined area of the RAM 113 in FIG.

  In the example of the write count table 400 in FIG. 8, for the sake of simplicity of explanation, it is assumed that the HDD 100 has one head 102 and the HDD 100 is configured by one track group (management track range). is doing.

  As shown in FIG. 8, the write count table 400 holds the physical address of the track group set as the management track range and the write count value counted for each management track range.

  The track group is a set of a predetermined number of tracks. Here, the number of tracks per track group is set to 100. However, the number of tracks is not limited to this and may be set in units of tracks or sectors. When data is written to a track in the track group, the number of times of writing held in the count table 400 is incremented by the number of times of writing.

  In FIG. 8, data is written 1000 times in the management track range of physical addresses 0 to 99, and data is written 10 times in the management track range of physical addresses 100 to 199, and management of physical addresses 200 to 299 is performed. In the example shown, data writing is executed 4000 times in the track range.

  In the HDD 100 according to the present embodiment, when the number of writings reaches a predetermined value, it is determined that the refresh process needs to be executed. However, for example, when sequential data is written in the management track range of the physical addresses 0 to 99, the HDD 100 determines that the execution of the refresh process is unnecessary in the management track range, and sets the write count value to the initial value. Reset to zero.

  Thus, in this embodiment, it is possible to determine whether or not it is necessary to execute the refresh process by referring to the write count table 400. Further, when sequential data writing is executed, unnecessary refresh processing can be avoided by resetting the write count value of the storage area in which writing has been performed to the initial value.

  In this embodiment, the write count table 400 and the track management table 300 are stored in the RAM 113 as described above. However, since the contents of the RAM 113 are lost when the power of the HDD 100 is shut off, for example, a configuration in which the contents are saved (saved) in a predetermined area of the disk 101 when necessary (for example, when the HDD 100 is shifted to the power saving state) may be provided. Be good. As a result, the contents including the count table 400 and the track management table 300 stored in the predetermined area of the disk 101 can be read and restored in the RAM 113 when the HDD 100 is started (when the power is turned on).

  Next, the flow of refresh processing in the HDD 100 of this embodiment will be described with reference to FIG. FIG. 9 is a flowchart showing the flow of refresh processing in the HDD 100 of this embodiment.

  First, when the power of the HDD 100 is turned on, the CPU 115 performs initialization processing and activation processing for the entire HDD 100 (S101). When the startup process is completed, the CPU 115 enters a command wait loop (S102 to S112) from the host system 200 via the HDC 110.

  Upon confirming reception of a command from the host system 200 in S102, the CPU 115 branches to S103 to exit the command wait loop and executes processing according to the command from the host system 200.

  When receiving the command, the CPU 115 determines whether the command from the host system 200 is a write command (S103). When the command from the host system 200 is not a write command (No in S103), the CPU 115 executes a process corresponding to the command (S104), and advances the process to S109.

  On the other hand, if the command from the host system 200 is a write command (Yes in S103), the CPU 115 determines whether or not the sequential write command has been received, or the LBA of the track to start writing is set to the LBA of the track that has finished writing last time. It is determined whether or not it is continuous (S105). Although not shown in the flowchart of FIG. 9, the process for converting the logical address specified by the write command from the host system 200 into the physical address has already been performed before reaching S105. And

  When the sequential write command is received in S105, or when the LBA of the track to start writing is continuous with the LBA of the track for which writing has been completed last (Yes in S105), the CPU 115 moves the process to S106.

  On the other hand, when the sequential write command is not received in S105, or when the LBA of the track to start writing is not continuous with the LBA of the track for which writing was completed last time (No in S105), the CPU 115 stores the data to be currently written. It is determined whether or not the stream data is written in an area of one track or more (S106).

  When the data to be currently written is not stream data to be written in an area of one track or more (No in S106), the CPU 115 increments the write count value of the management track included in the data writing range (S107), and moves the process to S109. . On the other hand, when the data to be written is stream data to be written in an area of one track or more (Yes in S106), the CPU 115 resets the write count value of the management track included in the data writing range (S108), The process proceeds to S109.

  When any one of S104, S107, and S108 is executed, the write command process is completed. Therefore, the CPU 115 performs command termination processing such as updating registers and releasing the busy state (S109), and returns to the command wait loop.

  Next, when it is determined in S102 in the command waiting loop that a command has not been received (No in S102), idle time processing is performed. The idle time process includes a refresh process of data stored in the track. The CPU 115 determines whether or not to perform refresh processing during idle (S110).

  In S110, the CPU 115 comprehensively determines whether it is necessary to immediately execute a command from the host system 200 without performing the refresh process, or whether the refresh process should be avoided. The command needs to be executed immediately when, for example, the command is received from the host system 200 immediately after S109. The situation where the refresh process should be avoided is when the HDD 100 is subjected to vibration exceeding a certain level from the outside, or when the environmental temperature of the HDD 100 is out of the temperature range in which the operation of the HDD 100 is guaranteed. It is a case where it is used in.

  When it is determined that the refresh process is to be performed (Yes in S111), the CPU 115 performs the refresh process (S112). On the contrary, when it is determined that the track refresh process is not performed (No in S111), the CPU 115 returns the process to S102. Thereafter, the CPU 115 repeats the above processing.

As described above, according to the present embodiment, it is possible to provide a recording apparatus and a recording method capable of efficiently rewriting data.
In addition, this invention is not limited to the said embodiment or its modification example as it is, A component can be deform | transformed and embodied in the range which does not deviate from the summary in an implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment or its modification. For example, you may delete a some component from all the components shown by embodiment or its modification.

1 is a block diagram showing a configuration of a magnetic disk device (HDD) according to an embodiment of the present invention. The conceptual diagram which shows the format containing the track arrangement | positioning of a present Example. The figure which shows the example of the data structure of the track management table of a present Example. 6 is a flowchart showing a flow of data read processing in the embodiment. 6 is a flowchart showing a flow of data writing processing in the embodiment. The figure which shows the state which wrote data A and B to the adjacent track on the disk in a present Example. The figure which shows the state which written the data sequentially in order from the adjacent track N + 1 on the disk in a present Example. The figure which shows the data structure example of the write count table of a present Example. 6 is a flowchart showing a flow of refresh processing in the HDD 100 of the present embodiment.

Explanation of symbols

100: Magnetic disk device (HDD)
DESCRIPTION OF SYMBOLS 101 ... Disk 102 ... Head 103 ... Spindle motor 104 ... Voice coil motor 105 ... Actuator 106 ... Motor driver 107 ... Head IC
108 ... Read / Write IC
109 ... Gate array 110 ... HDC
111 ... Buffer RAM
112 ... CPU bus 113 ... RAM
114: Flash ROM
115 ... CPU (controller)
121: Servo blocks 122, 124 ... Read / write block 123 ... Host block 125 ... Buffer block 201 ... Track 300 ... Track management table.
400 ... Light count table

Claims (10)

A magnetic disk provided with a storage area in which data is written;
A magnetic head for writing data to and reading data from a plurality of storage areas that divide the storage area;
A determination means for determining whether or not sequential writing for writing data to a plurality of storage areas in the order of physical addresses has been performed;
Write count management means for counting the number of times of writing in the storage area where data writing has been duplicated and returning the number of times of writing in the storage area determined to have been sequentially written by the determination means to an initial value;
A recording apparatus comprising: refresh means for referring to the number of times of writing and newly rewriting data written in a storage area using the magnetic head.   The determination unit determines that sequential writing has been performed when writing is started from a storage area that does not store data adjacent to a storage area that stores the latest data with the latest writing time. Item 2. The recording device according to Item 1.   3. The recording apparatus according to claim 2, wherein the determination unit determines that sequential writing has been performed when data is written in response to a command for writing data to each storage area in the order of logical addresses.   The determination unit determines that sequential writing has been performed when writing is started from a storage area that has a logical address next to the logical address of the storage area that stores the latest data and that does not store data. The recording apparatus according to claim 3.   The recording apparatus according to claim 1, wherein the determination unit determines that sequential writing has been performed when writing stream data in two or more storage areas.   The recording apparatus according to claim 1, wherein the determination unit determines that sequential writing has been performed with reference to a data write request command. The write count management means counts the number of writes in units of continuous track groups in the storage area,
5. The recording apparatus according to claim 4, wherein the refresh means refers to the number of times of writing and newly rewrites data stored in the track group using the magnetic head. The write count management means counts the write count in units of tracks in the storage area,
8. The recording apparatus according to claim 7, wherein the refresh means refers to the number of times of writing and newly rewrites data stored in each track using the magnetic head. The writing number management means counts the number of writings in units of sectors in which tracks in the storage area are divided,
8. The recording apparatus according to claim 7, wherein the refresh means refers to the number of times of writing and newly rewrites data stored in each sector using the magnetic head. A recording method for rewriting data written in a storage area,
Determining whether sequential writing was performed to write data in the order of physical addresses to a plurality of storage areas that divided the storage area of the magnetic disk,
Counting the number of times of writing in the storage area where data writing is duplicated, and returning the number of times of writing in the storage area determined to have been sequentially written by the determination means to the initial value,
A recording method characterized by referring to the number of times of writing and rewriting data written in a storage area using a magnetic head.

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