Disk device and recording method

Abstract

To provide a disk device capable of reducing impact on responses to a host device when system data is updated, and a recording method.SOLUTION: A disk device of the embodiment is a disk device controlled by using system data. The disk device has a disk, a non-volatile memory, and a controller. The controller can record the same system data in both the non-volatile memory and the disk.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] FIELD An embodiment of the present invention relates to a disk device and a recording method. [Background technology]

[0002] In a disk device, system data used to control the disk device is recorded on the disk. This system data is recorded in multiple layers on the disk to increase the reliability of the disk device. Therefore, when the system data is updated, all of the multiple pieces of system data recorded in multiple layers on the disk must be updated, which creates a problem of long time required to update the system data. This can cause problems such as delayed responses from the disk device to the host device when the system data is updated, which can reduce user convenience. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-283085 Summary of the Invention [Problem to be solved by the invention]

[0004] The problem to be solved by the present invention is to provide a disk device and a recording method that can reduce the effect on the response of a host device when system data is updated. [Means for solving the problem]

[0005] The disk device of the embodiment is a disk device controlled using system data. The disk device has a disk, a nonvolatile memory, and a controller. The controller is capable of recording the same system data in both the nonvolatile memory and the disk. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is a block diagram showing the configuration of a disk device according to a first embodiment. [Figure 2] FIG. 2 is a perspective view showing a disk according to the first embodiment. [Figure 3] FIG. 2 is a cross-sectional view showing the disk of the first embodiment. [Figure 4] 4 is a flowchart showing a part of a control procedure of a controller according to the first embodiment. [Figure 5] 10 is a flowchart showing an example of a procedure for system data writing processing according to the first embodiment. [Figure 6] 6 is a flowchart showing another part of the control procedure of the controller of the first embodiment. [Figure 7] 10 is a flowchart showing still another part of the control procedure of the controller of the first embodiment. [Figure 8] 10 is a flowchart showing an example of a procedure for system data writing processing according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0007] Hereinafter, a disk device and a recording method according to an embodiment will be described with reference to the drawings.

[0008] (First embodiment) FIG. 1 is a block diagram showing the configuration of a disk device 100 according to this embodiment. The disk device 100 according to this embodiment shown in FIG. 1 is a magnetic disk device incorporating a hard disk drive. The disk device 100 can store information as digital data. The disk device 100 is driven based on commands from a host device 40. The host device 40 is, for example, a personal computer. The host device 40 is not particularly limited as long as it is a device that issues commands to the disk device 100. The host device 40 can record information in the disk device 100 and read data recorded in the disk device 100.

[0009] 1, the disk drive 100 includes a disk 10, a head 11, a spindle motor 12, a voice coil motor 13, a head amplifier IC 14, a driver IC 15, a controller 20, a first volatile memory 31, a second volatile memory 32, and a non-volatile memory 33. The disk drive 100 is controlled using system data SD. The system data SD is recorded in the disk drive 100. The system data SD includes, for example, data indicating locations of defects in the recording area of ​​the disk 10, data for driving the spindle motor 12 and the voice coil motor 13, data for driving the head 11, and table data for managing the system data SD.

[0010] In this embodiment, the disk 10 is a magnetic disk. FIG. 2 is a perspective view showing the disk 10. The disk 10 is disk-shaped. The disk 10 is connected to a shaft 12a of a spindle motor 12. The disk 10 has a recording surface 10a. The recording surface 10a has a user data area UDA and a system data area SDA. User data transmitted from the higher-level device 40 is recorded in the user data area UDA. System data SD used to control the disk device 100 is recorded in the system data area SDA. Multiple copies of the same system data SD are recorded in the system data area SDA.

[0011] 2, the system data area SDA is provided closer to the outer periphery of the recording surface 10a than the user data area UDA. Note that the user data area UDA may be provided separately on the inner periphery and outer periphery of the recording surface 10a, and the system data area SDA may be provided between the inner user data area UDA and the outer user data area UDA.

[0012] FIG. 3 is a cross-sectional view showing a disk 10. As shown in FIG. 3, in this embodiment, a plurality of disks 10 are provided at intervals in the axial direction of the shaft 12a. In the example of FIG. 3, each of the plurality of disks 10 has a user data area UDA and a system data area SDA. Note that the system data area SDA may be provided on only some of the plurality of disks 10. Each disk 10 is rotated around the central axis of the shaft 12a by the spindle motor 12.

[0013] 1 is a magnetic head capable of reading data recorded on the disk 10 and writing data to the disk 10. Although not shown, the head 11 has a read head that reads data recorded on the disk 10 and a write head that writes data to the disk 10. A head 11 is provided for each disk 10. The head 11 is moved by a voice coil motor 13 between a position facing the recording surface 10a of the disk 10 and a position not facing the recording surface 10a of the disk 10. When the head 11 is in the position facing the recording surface 10a, it is capable of reading data from and writing data to the recording surface 10a.

[0014] Although not shown, the head amplifier IC 14 has a read amplifier and a write driver. The read amplifier amplifies the signal of data read from the disk 10 by the head 11 and outputs the amplified signal to a read / write channel 23 (described later) in the controller 20. The write driver outputs a write current to the head 11 according to the data output from the read / write channel 23. The head 11 writes data to the disk 10 based on the write current output from the write driver.

[0015] The driver IC 15 controls the driving of the spindle motor 12 and the driving of the voice coil motor 13 based on instructions from the controller 20 .

[0016] The controller 20 is a system controller that controls the disk device 100. The controller 20 is, for example, a large-scale integrated circuit (LSI) called a system-on-a-chip (SoC) in which multiple elements are integrated on a single chip. The controller 20 is electrically connected to a head amplifier IC 14, a driver IC 15, a first volatile memory 31, a second volatile memory 32, and a non-volatile memory 33. The controller 20 includes a microprocessor 21, a hard disk controller 22, and a read / write channel 23.

[0017] The hard disk controller 22 controls data transfer between the host device 40 and the read / write channel 23 based on commands from the microprocessor 21. The hard disk controller 22 is electrically connected to the microprocessor 21, the read / write channel 23, the head amplifier IC 14, the driver IC 15, the first volatile memory 31, the second volatile memory 32, and the nonvolatile memory 33. The hard disk controller 22 includes an interface control unit 22a, a buffer control unit 22b, and a format control unit 22c. The interface control unit 22a controls the interface with the host device 40. The interface control unit 22a reads commands input from the host device 40 and receives and transfers data. The buffer control unit 22b temporarily records data input from the host device 40 via the interface control unit 22a and data read from the disk 10 in the first volatile memory 31. The format control unit 22c converts the formats of data input from the buffer control unit 22b and data input from the read / write channel 23.

[0018] Based on instructions from the microprocessor 21, the read / write channel 23 performs signal processing on data sent from the disk 10 to the host device 40 and data sent from the host device 40 to the disk 10. The read / write channel 23 has a function of measuring the signal quality of the data, for example.

[0019] The first volatile memory 31 and the second volatile memory 32 are semiconductor memories in which stored data is lost when the power supply is cut off. In this embodiment, data is temporarily recorded in the first volatile memory 31 by the buffer control unit 22b. In this embodiment, the first volatile memory 31 is a dynamic random access memory (DRAM). Data necessary for processing in each unit of the disk device 100 is recorded in the second volatile memory 32. In this embodiment, the second volatile memory 32 is a static random access memory (SRAM). The first volatile memory 31 and the second volatile memory 32 may be integrated into a single volatile memory. The first volatile memory 31 may be an SRAM, a synchronous dynamic random access memory (SDRAM), a ferroelectric random access memory (FeRAM), a magnetoresistive random access memory (MRAM), or the like. The second volatile memory 32 may be a DRAM, SDRAM, FeRAM, MRAM, or the like.

[0020] The nonvolatile memory 33 is a semiconductor memory that continues to retain recorded data even when the power supply is cut off. In this embodiment, the nonvolatile memory 33 is a flash memory. The nonvolatile memory 33 is, for example, a NOR or NAND flash memory. The nonvolatile memory 33 stores at least part of the program for operating the disk device 100, as well as data required before reading and writing data from and to the disk 10. In this embodiment, the nonvolatile memory 33 stores multiple copies of system data SD that are identical to the system data SD stored in the system data area SDA of the disk 10. Note that the nonvolatile memory 33 may store only one piece of system data SD.

[0021] 1, the white arrows indicate the flow of user data UD. The user data UD input from the higher-level device 40 to the disk device 100 is input to the buffer control unit 22b via the interface control unit 22a, and is temporarily recorded in the first volatile memory 31 by the buffer control unit 22b. The user data UD recorded in the first volatile memory 31 is read by the buffer control unit 22b and converted into a format recordable on the disk 10 by the format control unit 22c. The converted user data UD is sent to the head amplifier IC 14 via the read / write channel 23, and written onto the disk 10 by the head 11. When the user data UD recorded on the disk 10 is read by the higher-level device 40, the user data UD is read in the reverse order of the procedure by which the user data UD is written onto the disk 10 described above.

[0022] The microprocessor 21 is a control unit and a main controller that controls each unit of the disk device 100. The microprocessor 21 controls the voice coil motor 13 via the driver IC 15 and executes servo control to position the head 11. The microprocessor 21 controls the spindle motor 12 via the driver IC 15 and rotates the disk 10. The microprocessor 21 controls the operation of writing data to the disk 10 (write operation). The microprocessor 21 selects a storage destination for data to be written to the disk 10. The microprocessor 21 controls the operation of reading data recorded on the disk 10 (read operation). The microprocessor 21 controls the processing of data read from the disk 10. The microprocessor 21 is electrically connected to each unit of the disk device 100.

[0023] The microprocessor 21 is capable of executing power loss protection processing that protects at least a portion of the data recorded in the first volatile memory 31 by recording it in the nonvolatile memory 33 when the power supply to the disk device 100 is stopped. When the microprocessor 21 determines, based on output from a power monitoring unit (not shown), that the power supply to the disk device 100 has been stopped, it executes power loss protection processing that records the data recorded in the first volatile memory 31 in the nonvolatile memory 33. Note that when executing the power loss protection processing, power to each unit is supplied from a capacitor (not shown) mounted in the disk device 100. In this way, the disk device 100 of this embodiment is equipped with a power loss protection function.

[0024] The controller 20 is capable of executing a system data write process. The system data write process includes a process of writing the system data SD to the nonvolatile memory 33 and a process of writing the system data SD to the disk 10. The system data write process is executed when the system data SD is updated. The system data SD is updated by, for example, the higher-level device 40. In this embodiment, the system data write process is executed by the microprocessor 21. A method of recording the system data SD used to control the disk device 100 includes executing the system data write process.

[0025] Fig. 4 is a flowchart showing part of the control procedure of the controller 20. In this embodiment, the control procedure shown in Fig. 4 is executed by the microprocessor 21 of the controller 20. As shown in Fig. 4, when the system data SD is updated (step S1), the controller 20 determines whether the size of the updated system data SD is equal to or smaller than a predetermined size that can be protected by the power loss protection function (step S2). When the system data SD is updated, the updated system data SD is temporarily recorded in the first volatile memory 31 from the higher-level device 40 via the interface control unit 22a and the buffer control unit 22b.

[0026] If the size of the updated system data SD is equal to or smaller than the predetermined size (step S2: YES), the controller 20 does not immediately start the system data write process, but instead keeps the updated system data SD temporarily recorded in the first volatile memory 31 in the first volatile memory 31 (step S3). On the other hand, if the size of the updated system data SD is larger than the predetermined size (step S2: NO), the controller 20 executes the system data write process (step S4). Note that the data in the system data SD whose size is equal to or smaller than the predetermined size may be, for example, table data for managing the system data SD.

[0027] 5 is a flowchart showing an example of the procedure for system data write processing. As shown in FIG. 5, in the system data write processing, the controller 20 writes the system data SD to the nonvolatile memory 33 (step S5). After writing the system data SD to the nonvolatile memory 33, the controller 20 determines whether or not processing based on a command from the higher-level device 40 is being executed (step S6). In this embodiment, the processing in step S6 corresponds to a determination process for determining whether or not processing based on a command from the higher-level device 40 is being executed. The processing based on a command from the higher-level device 40 includes, for example, a process for writing user data UD to the disc 10 and a process for reading user data UD from the disc 10.

[0028] If it is determined in step S6 that processing based on a command from the higher-level device 40 is not being executed, the controller 20 writes one piece of system data SD to the disk 10 (step S7). Thus, in the system data write processing of this embodiment, the controller 20 writes the system data SD to the non-volatile memory 33, and then writes the same system data SD to the disk 10. Furthermore, in the system data write processing of this embodiment, before writing the system data SD to the disk 10, the controller 20 executes a determination process of determining whether processing based on a command from the higher-level device 40 is being executed, i.e., the process of step S6.

[0029] In step S7 of this embodiment, the controller 20 copies one piece of system data SD temporarily recorded in the first volatile memory 31 and writes it to the disk 10, in the same manner as when writing the above-mentioned user data UD to the disk 10. In this way, the controller 20 can record the same system data SD in both the non-volatile memory 33 and the disk 10. Note that in step S7, the controller 20 may also copy the system data SD recorded in the non-volatile memory 33 and write it to the disk 10.

[0030] After writing one piece of system data SD to the disk 10 in step S7, the controller 20 determines whether a predetermined number of identical system data SDs have been written to the disk 10 (step S8). In this embodiment, the predetermined number of identical system data SDs to be written to the disk 10 is two or more. That is, in the system data write process of this embodiment, the controller 20 writes a plurality of identical system data SDs to the disk 10. Note that the predetermined number of identical system data SDs to be written to the disk 10 may be one.

[0031] If it is determined in step S8 that the predetermined number of identical system data SDs have not yet been written to the disks 10 (step S8: NO), the controller 20 executes step S6 again, and if processing based on a command from the higher-level device 40 has not been executed, writes one system data SD to the disks 10 again (step S7). Thus, in the system data write processing of this embodiment, the controller 20 executes the above-mentioned determination processing, i.e., the processing of step S6, every time before writing one system data SD to the disks 10. If it is determined in step S8 that the predetermined number of identical system data SDs have been written to the disks 10 (step S8: YES), the controller 20 ends the system data write processing (step S9).

[0032] In this embodiment, a plurality of identical system data SDs are stored as separate system data SDs recorded in the nonvolatile memory 33 and system data SDs recorded on the disks 10. In other words, in this embodiment, after the system data write process is completed, the controller 20 continues to maintain a state in which at least one identical system data SD is recorded in the nonvolatile memory 33 and at least one identical system data SD is recorded on the disks 10.

[0033] If it is determined in step S6 that processing based on a command from the higher-level device 40 is being executed (step S6: YES), the controller 20 interrupts the system data write processing (step S10). If the system data write processing is interrupted, the controller 20 suspends execution of the system data write processing until it is time to write the system data SD to the disk 10. Timings at which it is possible to write the system data SD to the disk 10 include when the controller 20 executes a specific process. In other words, if the system data write processing is interrupted, the controller 20 resumes the system data write processing when a specific process is executed.

[0034] It should be noted that "the controller 20 resumes the system data write process when a specific process is executed" includes cases where the controller 20 resumes the system data write process after it has been determined that a specific process will be executed but before the specific process is executed, cases where the controller 20 resumes the system data write process while the specific process is being executed, and cases where the controller 20 resumes the system data write process immediately after the specific process is executed.

[0035] The above-mentioned specific processes include processes whose execution time is sufficiently longer than the time required to write the system data SD to the disk 10, and processes that do not require a response to the host device 40. In this embodiment, "another time is sufficiently longer than a certain time" includes other times being 10 times or longer than the certain time.

[0036] Specifically, in this embodiment, the specific processes include a spin-up process that increases the rotation speed of the disk 10 to a specific rotation speed, and an unload process that moves the head 11 away from the disk 10. The spin-up process is a process that is executed before writing data to the disk 10 or reading data from the disk 10. The time required to execute the spin-up process is sufficiently longer than the time required to write system data SD to the disk 10. The unload process is a process that is executed when a time period during which no command is input from the host device 40 continues for more than a predetermined time. The unload process is a process that does not require a response to the host device 40. In the unload process, the controller 20 moves the head 11 to a position that does not face the disk 10.

[0037] The controller 20 determines, for example, the timing immediately after the spin-up process is completed and the timing after the decision to execute the unload process has been made and before the unload process is executed as the timing at which it is possible to write the system data SD to the disk 10, i.e., the timing at which it is possible to resume the system data write process.

[0038] 6 is a flowchart showing another part of the control procedure of the controller 20. In this embodiment, the control procedure shown in FIG. 6 is executed by the microprocessor 21 of the controller 20. As shown in FIG. 6, when the controller 20 determines that it is time to write the system data SD to the disk 10 (step S11), it determines whether writing of the system data SD to the nonvolatile memory 33 has been completed (step S12). When writing of the system data SD to the nonvolatile memory 33 has not been completed (step S12: NO), the controller 20 executes step S2 described above. When it is determined in step S2 that the size of the updated system data SD is equal to or smaller than the protectable predetermined size, there is no suspended system data write process, and therefore the controller 20 does not execute or resume the system data write process.

[0039] Note that when the system data SD is updated, step S2 described above is normally executed. Therefore, if the size of the updated system data SD exceeds the predetermined size that can be protected by the power loss protection function, a system data write process is executed, and the system data is written to the nonvolatile memory 33, regardless of whether or not a process based on a command from the higher-level device 40 is being executed. Therefore, if the size of the updated system data SD exceeds the predetermined size, the system data SD is normally written to the nonvolatile memory 33. However, if an error or the like occurs and the system data SD is updated, the system data write process may be interrupted before the system data SD is completely written to the nonvolatile memory 33. Even in this case, by determining in step S12 whether or not the system data SD has been written to the nonvolatile memory 33, the system data write process can be resumed and the system data SD can be written to the nonvolatile memory 33.

[0040] If the writing of the system data SD to the nonvolatile memory 33 is complete (step S12: YES), the controller 20 determines whether the writing of the system data SD to the disks 10 is complete (step S13). In step S13, the controller 20 determines whether the writing of a predetermined number of identical system data SD to the disks 10 is complete. If the controller 20 determines in step S13 that the writing of the system data SD to the disks 10 is complete (step S13: YES), the controller 20 determines that there is no suspended system data write process and does not execute or resume the system data write process. On the other hand, if the controller 20 determines in step S13 that the writing of the system data SD to the disks 10 is not complete (step S13: NO), the controller 20 resumes the system data write process (step S14). As shown in FIG. 5, if the system data write process is to be resumed in step S14, the controller 20 resumes the system data write process from step S6.

[0041] Next, a control procedure of the controller 20 when the power of the disk device 100 is turned on from off will be described. FIG. 7 is a flowchart showing yet another part of the control procedure of the controller 20. In this embodiment, the control procedure shown in FIG. 7 is executed by the microprocessor 21 of the controller 20. As shown in FIG. 7, when the power of the disk device 100 is turned on, the controller 20 determines whether or not there is system data SD protected by the power loss protection function (step S15). If the system data SD is protected by the power loss protection function, the system data SD is recorded in the nonvolatile memory 33. In step S15, the controller 20 determines whether or not there is system data SD in an area of ​​the recording area of ​​the nonvolatile memory 33 where data is recorded when protected by the power loss protection function. In the following description, the area of ​​the recording area of ​​the nonvolatile memory 33 where data is recorded when protected by the power loss protection function will be referred to as the protected area.

[0042] If it is determined in step S15 that system data SD protected by the power loss protection function exists (step S15: YES), the controller 20 executes a system data write process (step S16). That is, when the power of the disk device 100 is turned on, if there is system data SD protected by the power loss protection function, the controller 20 executes the system data write process. In this case, in step S5 of the system data write process, the controller 20 writes the system data SD recorded in the protection area of ​​the nonvolatile memory 33 to an area of ​​the recording area of ​​the nonvolatile memory 33 where the system data SD is recorded.

[0043] If it is determined in step S15 that there is no system data SD protected by the power loss protection function (step S15: NO), the controller 20 determines whether there is any suspended system data write processing (step S17). In step S17, the controller 20 determines whether writing of the system data SD to the disk 10 is complete, and determines whether there is any suspended system data write processing. In other words, when the power supply of the disk device 100 is turned on, if there is no system data SD protected by the power loss protection function, the controller 20 determines whether there is any suspended system data write processing.

[0044] If it is determined in step S17 that there is an interrupted system data write process (step S17: YES), the controller 20 resumes the interrupted system data write process (step S18). That is, when the power of the disk device 100 is turned ON, if there is an interrupted system data write process, the controller 20 resumes the system data write process. As shown in FIG. 5, when resuming the system data write process in step S18, the controller 20 resumes the system data write process from step S6. As shown in FIG. 7, if it is determined in step S17 that there is no interrupted system data write process (step S17: NO), the controller 20 does not write the system data SD.

[0045] According to this embodiment, the disk device 100 is a disk device controlled using system data SD and includes a disk 10, a nonvolatile memory 33, and a controller 20. The controller 20 can record the same system data SD in both the nonvolatile memory 33 and the disk 10. That is, the method for recording the system data SD includes recording the same system data SD in both the nonvolatile memory 33 and the disk 10. Therefore, it is possible to record some of the multiple identical system data SDs that need to be recorded in the nonvolatile memory 33. The time required to write the system data SD to the nonvolatile memory 33 is shorter than the time required to write the system data SD to the disk 10. Therefore, the time required to record multiple system data SDs can be shorter than when all of the multiple system data SDs are written to the disk 10. This prevents delays in the response from the disk device 100 to the host device 40, even when multiplexed system data SDs are updated. This reduces the impact on the response to the host device 40 when the system data SDs are updated.

[0046] Furthermore, according to this embodiment, the controller 20 can execute a system data write process that includes a process of writing system data SD to the nonvolatile memory 33 and a process of writing the system data SD to the disk 10. In the system data write process, the controller 20 writes the system data SD to the nonvolatile memory 33, and then writes the same system data SD to the disk 10. In other words, the method for recording the system data SD includes executing a system data write process that includes a process of writing the system data SD to the nonvolatile memory 33 and a process of writing the system data SD to the disk 10, and the system data write process includes writing the system data SD to the nonvolatile memory 33, and then writing the same system data SD to the disk 10. Therefore, by first recording the updated system data SD to the nonvolatile memory 33, which takes a relatively short time to write, it is possible to sequentially write the system data SD to the disk 10, which takes a relatively long time to write, while maintaining the state in which at least one system data SD is recorded. This allows the timing of writing to the disk 10 to be set so as not to affect the response to the host device 40 or to have a small effect on the response to the host device 40, thereby making it possible to write the system data SD to the disk 10 while reducing the effect on the response to the host device 40.

[0047] Furthermore, according to this embodiment, after the system data write process is completed, the controller 20 continues to maintain a state in which at least one identical system data SD is recorded in both the nonvolatile memory 33 and the disk 10. In other words, the method for recording the system data SD includes maintaining a state in which at least one identical system data SD is recorded in both the nonvolatile memory 33 and the disk 10 after the system data write process is completed. Therefore, one or more pieces of system data SD that need to be recorded in multiplexed form can also be recorded in the nonvolatile memory 33. This allows the system data area SDA on the disk 10 for recording the system data SD to be smaller, and the user data area UDA on the disk 10 for recording the user data UD to be relatively larger. Furthermore, the capacity of the nonvolatile memory 33 can be reduced compared to when all of the system data SD that need to be recorded in multiplexed form are recorded in the nonvolatile memory 33.

[0048] Furthermore, according to this embodiment, in the system data write process, before writing the system data SD to the disk 10, the controller 20 executes a determination process to determine whether or not a process based on a command from the host device 40 is being executed. If it is determined in the determination process that a process based on a command from the host device 40 is not being executed, the controller 20 writes at least one piece of system data SD to the disk 10. If it is determined in the determination process that a process based on a command from the host device 40 is being executed, the controller 20 suspends the system data write process. That is, the system data SD recording method includes the steps of: executing a determination process to determine whether or not a process based on a command from the host device 40 is being executed in the disk device 100 before writing the system data SD to the disk 10; writing at least one piece of system data SD to the disk 10 if it is determined in the determination process that a process based on a command from the host device 40 is not being executed; and suspending the system data write process if it is determined in the determination process that a process based on a command from the host device 40 is being executed. Therefore, if a process based on a command from the host device 40 is being executed, writing of the system data SD to the disk 10, which takes a relatively long time to write, is not executed. This makes it possible to further suppress delays in response to the host device 40 and further reduce the impact on the response to the host device 40. Also, when a process based on a command from the host device 40 is not being executed and the timing does not impact the response to the host device 40, the system data SD is written to the disk 10, and the system data write process can be quickly carried out.

[0049] Furthermore, according to this embodiment, in the system data write process, the controller 20 writes multiple identical system data SDs to the disk 10 and executes the above-described determination process each time before writing one system data SD to the disk 10. That is, in the system data SD recording method, the system data write process includes writing multiple identical system data SDs to the disk 10 and executing the above-described determination process each time before writing one system data SD to the disk 10. Therefore, even if a command is input from the host device 40 while writing system data SDs to the disk 10, the system data write process can be immediately interrupted after writing one system data SD. This further reduces delays in response to the host device 40 and further reduces the impact on the response to the host device 40.

[0050] Furthermore, according to this embodiment, if the system data write process is interrupted, the controller 20 resumes the system data write process when a specific process is executed. That is, the method for recording system data SD includes resuming the system data write process when a specific process is executed while the system data write process is interrupted. Therefore, by making the specific process a process that does not affect the response to the host device 40 or has a small effect on the response to the host device 40, the system data write process can be resumed while reducing the effect on the response to the host device 40.

[0051] Furthermore, according to this embodiment, the specific processing described above includes a spin-up process that increases the rotational speed of the disk 10 to a specific rotational speed. The time required for the spin-up process is significantly longer than the time required to write the system data SD to the disk 10. Therefore, even if the system data SD is written to the disk 10 after the spin-up process is executed, the additional time required to write the system data SD to the disk 10 can be considered an error in the time required for the spin-up process. Therefore, even if the system data SD is written to the disk 10 after the spin-up process is executed, the user is unlikely to recognize that the response to the host device 40 has been delayed due to the writing of the system data SD to the disk 10. This further reduces the impact on the response to the host device 40.

[0052] Furthermore, according to this embodiment, the disk device 100 includes a head 11 that can read data recorded on the disk 10 and write data to the disk 10. The specific processing described above includes an unload processing in which the head 11 is moved away from the disk 10. The unload processing is a processing that is executed when a command from the host device 40 is not executed for a predetermined time. Therefore, the timing at which it is decided to execute the unload processing is a timing at which it is not necessary to respond to the host device 40 and it is considered highly likely that a response to the host device 40 will not be generated immediately. Therefore, by writing the system data SD to the disk 10 before executing the unload processing at the timing at which it is decided to execute the unload processing, it is possible to further reduce the impact on the response to the host device 40.

[0053] Furthermore, according to this embodiment, the disk device 100 includes a first volatile memory 31. The disk device 100 is equipped with a power loss protection function that protects at least a portion of the data recorded in the first volatile memory 31 by recording it in the nonvolatile memory 33 when power supply to the disk device 100 is stopped. When the system data SD is updated, the controller 20 determines whether the size of the updated system data SD is equal to or smaller than a predetermined size that can be protected by the power loss protection function, and if the size of the updated system data SD is equal to or smaller than the predetermined size, the controller 20 stores the updated system data SD in the first volatile memory 31. If the size of the updated system data SD is larger than the predetermined size, the controller 20 executes a system data write process to write the updated system data SD to the nonvolatile memory 33. In other words, the method for recording system data SD includes, when the system data SD is updated, determining whether the size of the updated system data SD is equal to or smaller than a predetermined size that can be protected by the power loss protection function; storing the updated system data SD in the first volatile memory 31 if the size of the updated system data SD is equal to or smaller than the predetermined size; and executing a system data write process to write the updated system data SD to the nonvolatile memory 33 if the size of the updated system data SD is larger than the predetermined size. Therefore, when the system data SD is updated to a size equal to or smaller than the predetermined size that can be protected by the power loss protection function, the updated system data SD can be stored in the first volatile memory 31 without being written to the nonvolatile memory 33 while power is being supplied to the disk device 100. This reduces the frequency with which the system data SD recorded in the nonvolatile memory 33 is rewritten. This prevents the number of times data in the nonvolatile memory 33 is rewritten from reaching its upper limit.

[0054] Furthermore, according to this embodiment, when the power supply of the disk device 100 is turned on, if there is system data SD protected by the power loss protection function, the controller 20 executes a system data write process, and when the power supply of the disk device 100 is turned on and there is no system data SD protected by the power loss protection function, the controller 20 determines whether or not there is any suspended system data write process, and if there is suspended system data write process, the controller 20 resumes the system data write process. In other words, the method for recording the system data SD includes: when the power supply of the disk device 100 is turned on and there is no system data SD protected by the power loss protection function, the controller 20 executes a system data write process; and when the power supply of the disk device 100 is turned on and there is no system data SD protected by the power loss protection function, the controller 20 determines whether or not there is suspended system data write process, and if there is suspended system data write process, the controller 20 resumes the system data write process. Therefore, even if the power of the disk device 100 is turned off before the system data write process is executed or before the system data write process is completed, the system data write process can proceed when the power of the disk device 100 is turned on. Furthermore, the time required for the process executed when the power of the disk device 100 is turned on is much longer than the time required for the system data write process. Therefore, even if the system data write process is executed when the power of the disk device 100 is turned on, the user is unlikely to recognize that the response to the host device 40 has been delayed due to the system data write process. Therefore, the impact on the response to the host device 40 can be further reduced.

[0055] (Second embodiment) The second embodiment differs from the first embodiment in part of the control procedure of the controller 20. In the following description, the same components as those in the above-described embodiments will be denoted by the same reference numerals as appropriate, and the description thereof may be omitted.

[0056] FIG. 8 is a flowchart showing an example of the procedure for the system data write process in this embodiment. As shown in FIG. 8, in the system data write process of this embodiment, steps S19 and S20 are provided between steps S7 and S8. In this embodiment, the controller 20 writes one system data SD to the disk 10 in step S7, and then executes step S19. In step S19, the controller 20 determines whether the system data SD is recorded in the nonvolatile memory 33. If it is determined in step S19 that the system data SD is recorded in the nonvolatile memory 33 (step S19: YES), the controller 20 executes step S20. In step S20, the controller 20 erases the system data SD recorded in the nonvolatile memory 33. That is, in this embodiment, the controller 20 writes one or more system data SD to the disk 10 in the system data write process, and then erases the system data SD written in the nonvolatile memory 33. After erasing the system data SD recorded in the nonvolatile memory 33, the controller 20 executes step S8.

[0057] If it is determined in step S19 that the system data SD is not recorded in the nonvolatile memory 33 (step S19: NO), the controller 20 executes step S8 without executing step S20. In step S7 after deleting the system data SD recorded in the nonvolatile memory 33 in step S20, the controller 20 may copy the system data SD recorded on the disk 10 and write it to the disk 10, or may copy the system data SD recorded in the first volatile memory 31 and write it to the disk 10. Other control procedures by the controller 20 are similar to other control procedures by the controller 20 in the first embodiment.

[0058] As described above, in this embodiment, the system data SD is temporarily recorded in the nonvolatile memory 33 before it is written to the disc 10, but after any one piece of system data SD has been written to the disc 10, the system data SD recorded in the nonvolatile memory 33 is erased. Therefore, in this embodiment, when the system data write process is completed, all of the multiple identical system data SD will have been recorded on the disc 10.

[0059] According to this embodiment, the controller 20 erases the system data SD written to the nonvolatile memory 33 after writing one or more system data SDs to the disk 10 in the system data write process. In other words, the system data SD recording method of this embodiment includes erasing the system data SD written to the nonvolatile memory 33 after writing one or more system data SDs to the disk 10 in the system data write process. Therefore, when other system data SDs are updated, the area of ​​the nonvolatile memory 33 in which the system data SDs were recorded can be used as an area for recording the updated system data SDs. This allows the area reserved in the nonvolatile memory 33 for recording the system data SDs to be large enough to temporarily record the updated system data SDs when the system data SDs are updated. This reduces the area required for recording the system data SDs in the nonvolatile memory 33, thereby reducing the capacity of the nonvolatile memory 33.

[0060] According to at least one of the embodiments described above, the disk device 100 is a disk device controlled using system data SD. The disk device 100 has a disk 10, a nonvolatile memory 33, and a controller 20. The controller 20 can record the same system data SD in both the nonvolatile memory 33 and the disk 10. This reduces the impact on the response to the host device 40 when the system data SD is updated.

[0061] The number of identical system data SD recorded on the disk device 100 may be any number as long as they are recorded in multiplex on the disk device 100. Furthermore, in the disk device 100, as long as the system data SD can be recorded on both the nonvolatile memory 33 and the disk 10, the multiple identical system data SD held in the steady state may be recorded separately on the nonvolatile memory 33 and the disk 10 as in the first embodiment, or may be recorded only on the disk 10 as in the second embodiment. When the system data SD is held separately on the nonvolatile memory 33 and the disk 10, the number of system data SD recorded on the nonvolatile memory 33 may be the same as or different from the number of system data SD recorded on the disk 10. The disk device 100 does not need to be equipped with a power loss protection function. The disks included in the disk device may be optical disks or other disks other than magnetic disks, as long as they are capable of recording data. The controller 20 may include at least one of a first volatile memory 31, a second volatile memory 32, a non-volatile memory 33, a head amplifier IC 14, and a driver IC 15. The controller 20 does not necessarily include at least one or more components other than the microprocessor 21.

[0062] At least a part of the functions of the controller 20 described in the above-described embodiment is realized, for example, by the microprocessor 21 executing a program, i.e., software, recorded in at least one of the nonvolatile memory 33 and the disk 10. Note that at least a part of the functions of the controller 20 may be realized by hardware including circuitry such as an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), a GPU (Graphics Processing Unit), and the LSI of the above-described embodiment, or may be realized by a combination of software and hardware.

[0063] The disk device and recording method of the embodiment include the following additional aspects. (Appendix 1) A disk device controlled using system data, The disk and a non-volatile memory; A controller; Equipped with A disk device, wherein the controller is capable of recording the same system data in both the nonvolatile memory and the disk. (Appendix 2) the controller is capable of executing a system data write process including a process of writing the system data to the nonvolatile memory and a process of writing the system data to the disk; 2. The disk device according to claim 1, wherein in the system data write process, the controller writes the system data to the nonvolatile memory, and then writes the same system data to the disk. (Appendix 3) The disk device described in Appendix 2, wherein the controller continues to maintain a state in which at least one identical piece of system data is recorded in the non-volatile memory and on the disk after the system data writing process is completed. (Appendix 4) 3. The disk device according to claim 2, wherein the controller erases the system data written to the nonvolatile memory after writing one or more of the system data to the disk in the system data writing process. (Appendix 5) In the system data writing process, the controller before writing the system data to the disk, a determination process is performed to determine whether or not a process based on a command from a host device is being executed; writing at least one of the system data to the disk when it is determined in the determination process that the process based on the command has not been executed; 5. The disk device according to claim 2, wherein the system data write process is interrupted when it is determined in the determination process that a process based on the command is being executed. (Appendix 6) In the system data writing process, the controller writing a plurality of identical system data to the disk; 6. The disk device according to claim 5, wherein the determination process is executed every time before writing one of the system data to the disk. (Appendix 7) 7. The disk device according to claim 5, wherein the controller resumes the system data write process when a specific process is executed while the system data write process is suspended. (Appendix 8) 8. The disk device according to claim 7, wherein the specific process includes a spin-up process for increasing the rotation speed of the disk to a specific rotation speed. (Appendix 9) a head capable of reading data recorded on the disk and writing data to the disk; 9. The disk device according to claim 7, wherein the specific process includes an unload process of moving the head away from the disk. (Appendix 10) It has a volatile memory, a power loss protection function is implemented that protects at least a portion of the data recorded in the volatile memory by recording it in the nonvolatile memory when power supply to the disk device is stopped; The controller When the system data is updated, it is determined whether the size of the updated system data is equal to or smaller than a predetermined size that can be protected by the power loss protection function; When the size of the updated system data is equal to or smaller than the predetermined size, the updated system data is stored in the volatile memory; A disk device described in any one of Appendix 2 to Appendix 9, which executes the system data write process and writes the updated system data to the non-volatile memory when the size of the updated system data is larger than the specified size. (Appendix 11) The controller When the power supply of the disk device is turned on, if there is system data protected by the power loss protection function, the system data write process is executed; A disk device as described in Appendix 10, wherein when the power supply of the disk device is turned on, if there is no system data protected by the power loss protection function, it determines whether there is an interrupted system data write process, and if there is an interrupted system data write process, it resumes the system data write process. (Appendix 12) A method for recording system data used to control a disk device having a disk and a nonvolatile memory, comprising: A recording method comprising recording the same system data in both the non-volatile memory and the disk. (Appendix 13) executing a system data writing process including a process of writing the system data to the nonvolatile memory and a process of writing the system data to the disk; 13. The recording method according to claim 12, wherein the system data writing process includes writing the system data to the non-volatile memory, and then writing the same system data to the disc. (Appendix 14) The recording method described in Appendix 13, which includes, after the system data writing process is completed, continuing to maintain a state in which at least one identical piece of system data is recorded in the non-volatile memory and the disk. (Appendix 15) 14. The recording method according to claim 13, further comprising erasing the system data written to the non-volatile memory after writing one or more of the system data to the disc in the system data writing process. (Appendix 16) executing a determination process to determine whether or not a process based on a command from a host device is being executed in the disk device before writing the system data to the disk in the system data writing process; writing at least one of the system data to the disk when it is determined in the determination process that the process based on the command has not been executed; interrupting the system data writing process when it is determined in the determination process that a process based on the command is being executed; 16. The recording method according to any one of appendices 13 to 15, comprising: (Appendix 17) The system data writing process includes: writing a plurality of identical system data to the disk; executing the determination process at each timing before writing one of the system data to the disk; 17. The recording method of claim 16, comprising: (Appendix 18) 18. The recording method according to claim 16 or 17, further comprising resuming the system data writing process when a specific process is executed in the case where the system data writing process has been interrupted. (Appendix 19) the disk device is provided with a power loss protection function for recording at least a part of the data recorded in the volatile memory in the nonvolatile memory to protect the data when power supply to the disk device is stopped; When the system data is updated, determining whether or not the size of the updated system data is equal to or smaller than a predetermined size that can be protected by the power loss protection function; When the size of the updated system data is equal to or smaller than the predetermined size, storing the updated system data in the volatile memory; If the size of the updated system data is larger than the predetermined size, executing the system data writing process to write the updated system data to the nonvolatile memory; 19. The recording method according to any one of appendices 13 to 18, comprising: (Appendix 20) When the power supply of the disk device is turned on, if there is system data protected by the power loss protection function, executing the system data write process; When the power supply of the disk device is turned on, if there is no system data protected by the power loss protection function, determine whether or not there is an interrupted system data write process, and if there is an interrupted system data write process, resume the system data write process; 19. The recording method of claim 19, comprising:

[0064] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, as well as within the scope of the invention described in the claims and their equivalents. [Explanation of symbols]

[0065] 10... disk, 11... head, 20... controller, 31... first volatile memory (volatile memory), 33... non-volatile memory, 40... host device, 100... disk device, SD... system data

Claims

1. A disk device controlled using system data, The disk and a non-volatile memory; A controller; Equipped with A disk device, wherein the controller is capable of recording the same system data in both the nonvolatile memory and the disk.

2. the controller is capable of executing a system data write process including a process of writing the system data to the nonvolatile memory and a process of writing the system data to the disk; 2. The disk device according to claim 1, wherein in the system data write process, the controller writes the system data to the nonvolatile memory, and then writes the same system data to the disk.

3. 3. The disk device according to claim 2, wherein said controller continues to maintain a state in which at least one of the same system data is recorded in said nonvolatile memory and at least one of the same system data on said disk after said system data writing process is completed.

4. 3. The disk device according to claim 2, wherein the controller erases the system data written in the nonvolatile memory after writing one or more of the system data to the disk in the system data writing process.

5. In the system data writing process, the controller before writing the system data to the disk, a determination process is performed to determine whether or not a process based on a command from a host device is being executed; writing at least one of the system data to the disk when it is determined in the determination process that the process based on the command has not been executed; 3. The disk device according to claim 2, wherein the system data write process is interrupted when it is determined in the determination process that a process based on the command is being executed.

6. In the system data writing process, the controller writing a plurality of identical system data to the disk; 6. The disk device according to claim 5, wherein the determination process is executed every time before writing one of the system data to the disk.

7. 6. The disk device according to claim 5, wherein said controller resumes said system data write process when a specific process is executed while said system data write process is suspended.

8. 8. The disk device according to claim 7, wherein the specific process includes a spin-up process for increasing the rotation speed of the disk to a specific rotation speed.

9. a head capable of reading data recorded on the disk and writing data to the disk; 8. The disk drive according to claim 7, wherein the specific process includes an unload process for moving the head away from the disk.

10. It has a volatile memory, a power loss protection function is implemented that protects at least a portion of the data recorded in the volatile memory by recording it in the nonvolatile memory when power supply to the disk device is stopped; The controller When the system data is updated, it is determined whether the size of the updated system data is equal to or smaller than a predetermined size that can be protected by the power loss protection function; When the size of the updated system data is equal to or smaller than the predetermined size, the updated system data is stored in the volatile memory; 3. The disk device according to claim 2, wherein when the size of the updated system data is larger than the predetermined size, the system data write process is executed to write the updated system data to the nonvolatile memory.

11. The controller When the power supply of the disk device is turned on, if there is system data protected by the power loss protection function, the system data write process is executed; 11. The disk device according to claim 10, wherein when the power supply of the disk device is turned on, if there is no system data protected by the power loss protection function, it determines whether there is an interrupted system data write process, and if there is an interrupted system data write process, it resumes the system data write process.

12. A method for recording system data used to control a disk device having a disk and a nonvolatile memory, comprising: A recording method comprising recording the same system data in both the non-volatile memory and the disk.

13. executing a system data writing process including a process of writing the system data to the nonvolatile memory and a process of writing the system data to the disk; 13. The recording method according to claim 12, wherein the system data writing process includes writing the system data to the nonvolatile memory, and then writing the same system data to the disc.

14. 14. The recording method according to claim 13, further comprising: after the system data writing process is completed, continuing to maintain a state in which at least one of the same system data is recorded in the nonvolatile memory and the disc.

15. 14. The recording method according to claim 13, further comprising erasing the system data written in the nonvolatile memory after writing one or more of the system data to the disc in the system data writing process.

16. executing a determination process to determine whether or not a process based on a command from a host device is being executed in the disk device before writing the system data to the disk in the system data writing process; writing at least one of the system data to the disk when it is determined in the determination process that the process based on the command has not been executed; interrupting the system data writing process when it is determined in the determination process that a process based on the command is being executed; The recording method according to claim 13, comprising:

17. The system data writing process includes: writing a plurality of identical system data to the disk; executing the determination process at each timing before writing one of the system data to the disk; 17. The recording method according to claim 16, comprising:

18. 17. The recording method according to claim 16, further comprising restarting the system data writing process when a specific process is executed in the case where the system data writing process has been interrupted.

19. the disk device is provided with a power loss protection function for recording at least a part of the data recorded in the volatile memory in the nonvolatile memory to protect the data when power supply to the disk device is stopped; When the system data is updated, determining whether or not the size of the updated system data is equal to or smaller than a predetermined size that can be protected by the power loss protection function; When the size of the updated system data is equal to or smaller than the predetermined size, storing the updated system data in the volatile memory; If the size of the updated system data is larger than the predetermined size, executing the system data writing process to write the updated system data to the nonvolatile memory; The recording method according to claim 13, comprising:

20. When the power supply of the disk device is turned on, if there is system data protected by the power loss protection function, executing the system data write process; When the power supply of the disk device is turned on, if there is no system data protected by the power loss protection function, determine whether or not there is an interrupted system data write process, and if there is an interrupted system data write process, resume the system data write process; 20. The recording method of claim 19, comprising:

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