Disk device

Abstract

The embodiment provides a magnetic disk device with high convenience. The magnetic disk device of the embodiment comprises a magnetic disk, a magnetic head, a sensor, a nonvolatile semiconductor storage device and a controller. Writing and reading are performed with respect to the magnetic disk. The sensor detects the degree of physical influence received from the outside. When the detection value of the sensor satisfies the condition for abnormality determination, the controller generates a log, and saves the log to the semiconductor storage device in accordance with the generation of the log.

Description

[0001] Related Application

[0002] This application claims priority based on Japanese Patent Application No. 2019-147664 (filing date: August 9, 2019). This application includes all the contents of the basic application by reference. Technical Field

[0003] This embodiment relates to a magnetic disk device. Background Art

[0004] In the past, magnetic disk devices generally recorded abnormal information on the magnetic disk. Therefore, when the magnetic head, magnetic disk, spindle motor, motor driver IC (Integrated Circuit) or head IC (Integrated Circuit) was broken, the magnetic disk could not be accessed, and the abnormal information could not be obtained.

[0005] For example, when a magnetic disk device is returned from the market to the manufacturer, the manufacturer cannot obtain information on the abnormality due to the above-mentioned reasons, and may not be able to find out the cause of the abnormality. Summary of the invention

[0006] One embodiment provides a magnetic disk device with high convenience.

[0007] According to one embodiment, a magnetic disk device includes a magnetic disk, a magnetic head, a sensor, a nonvolatile semiconductor storage device, and a controller. Writing and reading are performed with respect to the magnetic disk. The sensor detects the degree of physical influence received from the outside. When the detection value of the sensor satisfies the condition for abnormality determination, the controller generates a log, and corresponding to the generation of the log, saves the log to the semiconductor storage device. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 This is a schematic diagram showing an example of the configuration of the magnetic disk device according to the first embodiment.

[0009] Figure 2 This is a diagram showing an example of the structure of the magnetic disk according to the first embodiment.

[0010] Figure 3 This is a schematic diagram showing an example of arrangement of the RV sensor according to the first embodiment.

[0011] Figure 4 This is a flowchart for explaining an example of the operation of acquiring the detection value of the sensor and determining the abnormality according to the first embodiment.

[0012] Figure 5This is a diagram for explaining an example of the configuration of the abnormality log according to the first embodiment.

[0013] Figure 6 This is a flowchart for explaining an example of the operation of writing an abnormality log to a disk according to the first embodiment.

[0014] Figure 7 This is a flowchart for explaining an example of an operation for acquiring an abnormality log from a failed magnetic disk device when a magnetic disk device fails according to the first embodiment.

[0015] Figure 8 This is a flowchart for explaining an example of the operation of acquiring the detection value of the sensor and determining the abnormality according to the second embodiment.

[0016] Fig. 9 This is a flowchart for explaining an example of the operation of acquiring detection values ​​of the sensor and determining abnormality according to the third embodiment.

[0017] Fig.10 This is a flowchart for explaining an example of the operation of acquiring detection values ​​of the sensor and determining abnormality according to the fourth embodiment. DETAILED DESCRIPTION

[0018] Hereinafter, the magnetic disk device according to the embodiment will be described in detail with reference to the drawings. However, the present invention is not limited to these embodiments.

[0019] (First embodiment)

[0020] Figure 1 This is a schematic diagram showing an example of the configuration of the magnetic disk device 1 according to the first embodiment.

[0021] The disk device 1 can be connected to a host 2. The host 2 is a computer device that issues commands for causing the disk device 1 to perform desired actions. The commands include, for example, a write command for writing data to the disk device 1 and a read command for reading data from the disk device 1. The host 2 is, for example, a server or a personal computer.

[0022] The magnetic disk device 1 includes a magnetic disk 100, an SPM (Spindle Motor) 101, a VCM (Voice Coil Motor) 102, a head actuator 103, a magnetic head 104, a head IC 105, an R (Read) / W (Write) channel 106, an HDC (Hard Disk Controller) 107, a CPU (Central Processing Unit) 108, a motor driver IC 109, an impact sensor 110, a pair of RV (Rotational Vibration) sensors 111A and 111B, a voltage sensor 112, an air pressure sensor 113, and a temperature sensor 114.

[0023] The R / W channel 106, HDC 107, and CPU 108 are mounted on the control substrate 140. The R / W channel 106, HDC 107, and CPU 108 mounted on the control substrate 140 constitute the controller of the embodiment. In addition, the components of the controller are not limited thereto. The controller may also be composed of a part of the R / W channel 106, HDC 107, and CPU 108. In addition, the controller may include any components other than the R / W channel 106, HDC 107, and CPU 108.

[0024] The magnetic disk 100 is a storage medium in which a magnetic layer is formed on a disk-shaped object such as an aluminum or glass substrate.

[0025] Figure 2 1 is a diagram showing an example of the structure of the magnetic disk 100 according to the first embodiment. Servo information is written to the magnetic layer formed on the surface of the magnetic disk 100 by a servo writer or the like before shipment. In addition, the servo information can also be written to the magnetic disk 100 after shipment by self-servo writing (SSW). Figure 2 In the embodiment of the present invention, as an example of the configuration of the servo area in which the servo information is written, a servo area 100a arranged radially is shown. A plurality of concentric tracks 100b are provided at a predetermined interval in the radial direction of the magnetic disk 100. Many sectors are continuously formed on the circumference of each track 100b. For each sector, data is written and read by a magnetic head 104 described later.

[0026] Return the description Figure 1 The SPM 101 rotates the magnetic disk 100 .

[0027] A magnetic head 104 is mounted on the front end of the head actuator 103. The magnetic head 104 is supported by the head actuator 103 so as to face the recording surface of the magnetic disk 100.

[0028] The VCM 102 drives the head actuator 103 , thereby enabling the magnetic head 104 attached to the front end of the head actuator 103 to move relative to the recording surface of the magnetic disk 100 .

[0029] The magnetic head 104 writes data to the magnetic disk 100 (more specifically, the magnetic layer of the magnetic disk 100 ) and reads data from the magnetic disk 100 .

[0030] The head IC 105 is an amplifier that amplifies a signal read from the magnetic disk 100 by the magnetic head 104 and a signal written to the magnetic disk 100 .

[0031] The R / W channel 106 encodes data written to the magnetic disk 100 or decodes a signal read from the magnetic disk 100 .

[0032] The HDC 107 is connected to the host 2 and transmits and receives data and commands to and from the host 2. In addition, the HDC 107 writes and reads data to and from the magnetic disk 100.

[0033] The motor driver IC 109 drives the SPM 101 and the VCM 102 . The motor driver IC 109 also acquires detection values ​​of the impact sensor 110 , the RV sensors 111A and 111B, the voltage sensor 112 , the air pressure sensor 113 , and the temperature sensor 114 , and transmits the acquired detection values ​​to the CPU 108 .

[0034] The impact sensor 110, RV sensors 111A, 111B, voltage sensor 112, air pressure sensor 113 and temperature sensor 114 are sensors for detecting the degree of physical influence received by the magnetic disk device 1 from the outside. The physical influence is impact, vibration, voltage of the supplied power, air pressure or temperature, etc. In addition, the detection value of the sensor represents the degree of the physical influence using numerical information. The numerical information can be any information indicating the degree of the physical influence. For example, the numerical information obtained by the sensor can be information represented by any existing unit system. Alternatively, the numerical information obtained by the sensor can be information not represented by the existing unit system, but an indicator having a correlation with the degree of the physical influence. For example, the detection value of the temperature sensor 112 can be numerical information represented by Celsius, Fahrenheit or K (Kelvin), or it can be numerical information that is simply different from the above-mentioned unit system and takes a larger value as the temperature increases.

[0035] The RV sensors 111A and 111B detect the amount of vibration of the magnetic disk 100 in a substantially circumferential direction.

[0036] Figure 3This is a schematic diagram showing an example of the configuration of the RV sensors 111A and 111B according to the first embodiment. In this figure, the short side direction of the housing 130 of the magnetic disk device 1 is set as the X direction, the long side direction is set as the Y direction, and the thickness direction (that is, the axial direction of the SPM 101) is set as the Z direction.

[0037] RV sensors 111A and 111B are provided at two diagonally opposite corners in the housing 130 of the magnetic disk device 1. The RV sensors 111A and 111B can detect the amount of vibration in the X direction and the Y direction, respectively. The difference between the detection value of the RV sensor 111A and the detection value of the RV sensor 111B is amplified by a differential amplifier (not shown), thereby directly detecting the amount of vibration in the substantially circumferential direction of the magnetic disk 100. The amount of vibration in the substantially circumferential direction of the magnetic disk 100 is, for example, the amount of vibration in the direction of arrow 200 when the housing 130 moves to the position 130′.

[0038] Furthermore, the RV sensors 111A and 111B can detect the amount of vibration as a displacement, a velocity, an acceleration, or any other physical quantity.

[0039] In addition, the position where the differential amplifier is arranged is not limited to a specific position. In one example, the differential amplifier is placed in the motor driver IC 109 .

[0040] Hereinafter, the RV sensors 111A and 111B are collectively referred to as RV sensors 111. The detection value obtained by the RV sensor 111 means the amount of vibration in the substantially circumferential direction of the magnetic disk 100 obtained from the detection values ​​of the RV sensors 111A and 111B.

[0041] Return the description again Figure 1 The impact sensor 110 can detect the amount of vibration in each direction of X, Y, and Z. The amount of vibration detected by the impact sensor 110 is a displacement, a velocity, an acceleration, or any other physical quantity. The motor driver IC 109 or the CPU 108 synthesizes the amounts of vibration in each direction detected by the impact sensor 110 to calculate the amount of vibration in the vibration direction. In addition, the components for calculating the amount of vibration in the vibration direction are not limited to the motor driver IC 109 and the CPU 108.

[0042] Hereinafter, the detection value obtained by the impact sensor 110 means the amount of vibration in the vibration direction.

[0043] The voltage sensor 112 detects the voltage of power supplied from the outside to the magnetic disk device 1 .

[0044] The air pressure sensor 113 detects the air pressure.

[0045] The temperature sensor 114 detects temperature.

[0046] In addition, any circuit such as an AD (Analog Digital) converter, an amplifier or a filter circuit may be interposed on the wires until the signals output by various sensors (for the motor driver IC 109, the impact sensor 110, the RV sensors 111A and 111B, the voltage sensor 112, the air pressure sensor 113 and the temperature sensor 114) are obtained as detection values ​​by the motor driver IC 109. In addition, as the standard of the bus connecting the various sensors to the motor driver IC 109, any standard can be adopted. For example, I2C can be adopted as the standard of the above-mentioned bus. In addition, various sensors can also be connected to the CPU 108 or the HDC 107 instead of the motor driver IC 109.

[0047] The CPU 108 comprehensively controls the operation of each component in the magnetic disk device 1 .

[0048] In addition, the CPU 108 includes a FROM (Flash Read Only Memory) 120 and a RAM (Random Access Memory) 121 .

[0049] FROM120 is an example of a nonvolatile semiconductor storage device. As a nonvolatile semiconductor storage device, a semiconductor storage device other than FROM, such as MRAM (Magnetoresistive Random Access Memory) or PCM (Phase-Change Memory), etc. can be used. In addition, when the magnetic disk device 1 is configured as a hybrid HDD (Hard Disk Drive) having an SSD (Solid State Drive) and a NAND-type flash memory, the SSD and NAND-type flash memory can be used as nonvolatile semiconductor storage devices of the embodiment.

[0050] The firmware program is stored in advance in the FROM 120. The CPU 108 implements the above control by loading the firmware program stored in the FROM 120 into the RAM 121 and executing the firmware program loaded into the RAM 121. When executing the above control, the CPU 108 can use the RAM 121 as a work area.

[0051] Furthermore, the CPU 108 determines whether the magnetic disk device 1 is receiving an abnormal physical influence from outside as part of the control.

[0052] Specifically, the CPU 108 determines whether the detection value of the sensor (regarding the motor driver IC 109, the impact sensor 110, the RV sensor 111A, 111B, the voltage sensor 112, the air pressure sensor 113 or the temperature sensor 114) satisfies the condition for abnormality determination. When the detection value of the sensor satisfies the condition, the CPU 108 generates an abnormality log, which is information at the time of the abnormality. In response to the generation of the abnormality log, the CPU 108 saves the abnormality log to the FROM 120.

[0053] Thus, even if the magnetic head 104, magnetic disk 100, SPM 101, motor driver IC 109 or head IC 105 is damaged due to the magnetic disk device 1 being exposed to abnormal physical influences such as abnormal impact, abnormal supply voltage, abnormal air pressure or abnormal temperature, and reading from the magnetic disk 100 is impossible, the abnormal log can be obtained from FROM 120.

[0054] Saving the exception log to FROM120 in accordance with the generation of the exception log means that the exception log is saved to FROM120 with the generation of the exception log as an opportunity. Thus, after the exception log is generated, the exception log is saved in FROM120 without leaving any time. Here, as an example, it is assumed that the exception log is saved to FROM120 immediately after the CPU108 generates the exception log for explanation. In addition, as described in detail later, the exception log is saved not only to FROM120 but also to RAM121. The exception log saved to RAM121 is written to the disk 100 at a timing after a period of time has passed since it was generated, such as the timing when the disk device 1 becomes an idle state. CPU108 only needs to save the exception log to FROM120 at least before completing the saving of the exception log to the disk 100 via RAM121.

[0055] Furthermore, the conditions for abnormality determination can be arbitrarily configured as long as they can estimate whether the magnetic disk device 1 is receiving an abnormal physical influence from the outside. Furthermore, the conditions for abnormality determination can be arbitrarily configured according to the type of abnormal physical influence to be detected.

[0056] In the case where it is estimated that the magnetic disk device 1 is subjected to an abnormal physical impact from the outside, the abnormal log can include information about the detection values ​​collected by the motor driver IC 109 from one or more of the impact sensor 110, the RV sensors 111A and 111B, the voltage sensor 112, the air pressure sensor 113, and the temperature sensor 114, or numerical information obtained by processing the detection values. The abnormal log is used for analyzing the cause of the failure, etc., and can be arbitrarily configured according to the analysis method.

[0057] An example of the first embodiment of the conditions for abnormality determination and the abnormality log will be described later.

[0058] In addition, if you use Figure 2 As described above, the servo information is recorded on the tracks at substantially equal intervals. Therefore, the servo information is read at substantially constant time intervals. After the servo information is read, an interrupt is generated to the CPU 108, and the CPU 108 and the HDC 107 perform position calculations based on the servo information in response to the interrupt.

[0059] In the first embodiment, for example, when the interruption occurs, the CPU 108 performs calculation of the position based on the servo information, and acquires the detection values ​​of various sensors and determines abnormalities. That is, the CPU 108 acquires the detection values ​​of various sensors and determines abnormalities every time the servo information is read. Hereinafter, the interruption caused by the reading of the servo information is referred to as a servo interruption.

[0060] In addition, the timing of obtaining the detection values ​​of various sensors and determining the abnormality is not limited to the timing of the servo interruption. CPU108 can obtain the detection values ​​of various sensors at any timing and perform abnormality determination at any timing. For example, CPU108 or other components of the controller can also always obtain the detection values ​​of various sensors. In addition, CPU108 or other components of the controller can also regularly obtain the detection values ​​of various sensors at a timing different from the servo interruption.

[0061] Next, the operation of the magnetic disk device 1 according to the first embodiment will be described.

[0062] Figure 4 This is a flowchart for explaining an example of the operation of acquiring the detection value of the sensor and determining the abnormality according to the first embodiment.

[0063] When a servo interruption occurs (S101), the CPU 108 obtains the detection values ​​of various sensors (S102). Then, the CPU 108 determines whether the condition that the detection value of the impact sensor 110 exceeds the limit value S1 or the detection value of the RV sensor 111 exceeds the limit value S2 is satisfied (S103). In addition, S1 and S2 are preset. S1 is a limit value compared with the detection value of the impact sensor 110, and S2 is a limit value compared with the detection value of the RV sensor 111.

[0064] When the determination condition of S103 is satisfied ( S103 : YES), the CPU 108 determines whether the duration of the impact is being measured ( S104 ).

[0065] The duration of the impact is recorded as Duration. Duration is measured for each sensor. That is, the duration of the impact includes the Duration involved in the impact sensor 110 and the Duration involved in the RV sensor 111. The Duration involved in the impact sensor 110 is the time during which the detection value of the impact sensor 110 continues to exceed the limit value S1. The Duration involved in the RV sensor 111 is the time during which the detection value of the RV sensor 111 continues to exceed the limit value S2. If any Duration is being measured, it is determined as yes in the determination process of S104. If all Durations are not being measured, it is determined as no in the determination process of S104.

[0066] When measuring the Duration (S104: Yes), or after S105, CPU 108 determines whether any Duration exceeds the threshold value D1 (S106). When any Duration exceeds the threshold value D1 (S106: Yes), CPU 108 determines whether the log generation routine is being executed (S107). When the log generation routine is not being executed (S107: No), CPU 108 starts the log generation routine (S108).

[0067] The log generation routine is a process for generating an abnormality log. That is, in the first embodiment, the condition that the detection value of one of the impact sensor 110 and the RV sensor 111 exceeds the corresponding limit value and the duration in measurement exceeds the threshold value D1 corresponds to the condition for abnormality determination.

[0068] The log generation routine maintains the execution state until the collection of all the information constituting the abnormality log is completed, for example.

[0069] Figure 5 This is a diagram for explaining an example of the configuration of an abnormality log according to Embodiment 1. In this diagram, the vertical axis represents the detection value of the impact sensor 110, and the horizontal axis represents time.

[0070] The abnormality log may include the period from when the detection value of the impact sensor 110 exceeds the limit value S1 to when the detection value of the impact sensor 110 no longer exceeds the limit value S1, that is, Figure 5 In addition, the exception log may include the maximum value observed during the above period, that is, Figure 5 The abnormality log may include the time from when the detection value of the shock sensor 110 exceeds the limit value S1 to when the maximum value of the shock is observed. The abnormality log may also include the cumulative value of the value offset by the limit value S1 from the detection value observed during the above period, that is, Figure 5 The area of ​​the oblique line portion shown (shock cumulative value). In addition, the abnormality log may include the original waveform of the detection value from when the detection value of the shock sensor 110 exceeds the limit value S1 to an arbitrary timing.

[0071] For example, CPU108 saves the sensor's detection value (especially the detection value that exceeds the limit value) to RAM121 in a chronological order from the timing when the measurement of Duration is started. CPU108 can calculate the abnormal sensor information, the impact maximum value, the time when the impact maximum value is observed, the impact cumulative value and the original waveform based on the detection value group saved in RAM121 in a chronological order. The abnormal sensor information refers to the information of the sensor that indicates the output of the abnormal detection value. The detection value group saved in RAM121 can be deleted when the generation of the abnormal log is completed (the timing of S112 described later) or when the log generation routine is not started and the measurement of Duration is completed (the timing of S114 described later).

[0072] also, Figure 5 The example of the abnormality log generated based on the detection value of the shock sensor 110 is shown. The CPU 108 can generate the abnormality log based on the detection value of the RV sensor 111 by the same method as the abnormality log generated based on the detection value of the shock sensor 110 .

[0073] In addition, the abnormality log can include arbitrary information in addition to the information obtained from the impact sensor 110 or the information obtained from the RV sensor 111. For example, the abnormality log can include the detection value of an arbitrary sensor or numerical information obtained by processing the detection value of an arbitrary sensor.

[0074] Return the description Figure 4 When the log generation routine is being executed (S107: Yes), or after S108, the control returns to S101. Then, the closed-loop processing of S101 to S108 is repeatedly executed until the collection of all the information constituting the abnormal log is completed. In the first embodiment, since the abnormal log is set to include Duration, the closed-loop processing of S101 to S108 is repeatedly executed until it is determined to be No in the determination process of S103.

[0075] If all the Durations do not exceed the threshold value D1 ( S106 : NO), the control returns to S101 .

[0076] When the judgment condition of S103 is not met (S103: No), CPU108 determines whether the log generation routine is being executed (S109). When the log generation routine is being executed (S109: Yes), CPU108 ends the measurement of Duration (S110). Then, CPU108 generates an abnormal log and immediately saves the generated abnormal log to FROM120 and RAM121 (S111). The abnormal log includes, for example, information of abnormal sensors, maximum impact value, Duration, time when the maximum impact value is observed, impact cumulative value and original waveform. The information of abnormal sensors here refers to the information of sensors indicating that the measured Duration of the impact sensor 110 and the RV sensor 111 exceeds the threshold value D1.

[0077] After S111 , CPU 108 ends the log generation routine ( S112 ), and the control returns to S101 .

[0078] When the log generation routine is not being executed (S109: No), CPU 108 determines whether the Duration is being measured (S113). When the Duration is being measured (S113: Yes), CPU 108 ends the Duration measurement (S114). When the Duration is not being measured (S113: No), or after S114, the control returns to S101.

[0079] In this way, when the detection value of the impact sensor and the detection value of the RV sensor exceed the corresponding limit value, the measurement of the Duration involved in the sensor whose detection value exceeds the corresponding limit value starts (S103: Yes, S104: No, S105). Then, when the Duration exceeds the threshold value D1, the log generation routine is started, and the generation of the abnormal log is determined (S106: Yes, S107: No, S108). When the log generation routine is started, the acquisition of the detection value is continued until the collection of all the information constituting the abnormal log is completed. Here, as an example, the acquisition of the detection value is continued until the judgment condition of S113 is no longer satisfied, but the condition for stopping the acquisition of the detection value is not limited to this. For example, in the case where the acquisition of the original waveform is to be continued for a predetermined time, the acquisition of the detection value can also be continued until the predetermined time has passed. When the collection of all the information constituting the abnormal log is completed, the abnormal log is generated and the abnormal log is immediately saved to FROM120 and RAM121 (S112).

[0080] In addition, when the determination condition of S103 is satisfied, the CPU 108 may also Figure 4In addition to the processing of the magnetic disk device 1, various processing for preventing the magnetic disk device 1 from malfunctioning is also performed. For example, the CPU 108 can temporarily retreat the magnetic head 104 to a position where it is difficult for the magnetic head 104 to malfunction. The position where it is difficult for the magnetic head 104 to malfunction can be, for example, an area on the inner circumference side of the magnetic disk 100, or a position of a slope loading mechanism not shown in the figure. Alternatively, the CPU 108 can also make the rotation speed of the magnetic disk 100 lower than the normal speed.

[0081] The abnormality log stored in the RAM 121 is also written to the magnetic disk 100 at a predetermined timing.

[0082] Figure 6 This is a flowchart for explaining an example of the operation of writing the abnormality log to the magnetic disk 100 according to the first embodiment.

[0083] The CPU 108 determines whether the magnetic disk device 1 is in an idle state (S201). The idle state is, for example, a state in which there are no unprocessed commands among the commands received from the host 2. The idle state is not limited to this.

[0084] When the magnetic disk device 1 is in the idle state (S201: YES), the CPU 108 determines whether an abnormality log is stored in the RAM 121 (S202). If an abnormality log is stored in the RAM 121 (S202: YES), the CPU 108 causes the HDC 107 to store the abnormality log stored in the RAM 121 in the magnetic disk 100 (S203).

[0085] When the magnetic disk device 1 is not in the idle state ( S201 : No), or when the abnormality log is not stored in the RAM 121 ( S202 : No), or after S203 , the control returns to S201 .

[0086] In the above example, the abnormality log in the RAM 121 is written to the magnetic disk 100 when the magnetic disk device 1 is in the idle state. The timing at which the abnormality log in the RAM 121 is written to the magnetic disk 100 by the magnetic disk device 1 is not limited to this.

[0087] In this way, the abnormality log stored in RAM 121 is written to disk 100 after a certain period of time has passed since it was generated. In the first embodiment, the abnormality log is also written to FROM 120 immediately after it is generated. Thus, even if the disk device 1 fails or the disk device 1 is powered off before the abnormality log stored in RAM 121 is written to disk 100, thereby causing the abnormality log stored in RAM 121 to disappear, an abnormality log with the same content can be obtained from FROM 120.

[0088] Figure 7This is a flowchart for explaining an example of an operation for acquiring an abnormality log from the failed magnetic disk device 1 when a failure occurs in the magnetic disk device 1 according to the first embodiment.

[0089] First, an operator connects the magnetic disk device 1 to a computer (S301). The operator may be, for example, a user of the magnetic disk device 1. Alternatively, the operator may be a manufacturer who has received a magnetic disk device 1 returned from a user.

[0090] Next, the operator uses a computer to read the abnormality log stored in FROM 120 (S302). The operator can analyze the cause of the failure based on the read abnormality log (S303).

[0091] In the above description, it is assumed that the CPU 108 performs abnormality determination and generates an abnormality log. The abnormality determination and the generation of an abnormality log may be performed by the HDC 107. That is, the control substrate 140 as a controller performs abnormality determination and generates an abnormality log.

[0092] In addition, although it is described that various sensors are connected to the motor driver IC 109, a part or all of the sensors may be connected to the CPU 108, the HDC 107, and the like.

[0093] In addition, the log generation routine is assumed to be in a state of being executed until the collection of all information constituting the abnormal log is completed. Even in the period until the collection of all information constituting the abnormal log is completed, the log generation routine can save the detection values ​​obtained each time the closed loop processing of S101 to S108 is executed to FROM120 immediately after acquisition. The detection values ​​saved in FROM120 until the collection of all information constituting the abnormal log is completed can also be set as the abnormal log.

[0094] As described above, according to the first embodiment, the magnetic disk device 1 includes the shock sensor 110 and the RV sensor 111 as sensors for detecting the degree of physical influence received from the outside. The CPU 108 generates an abnormality log when the detection value of either the shock sensor 110 or the RV sensor 111 satisfies the condition for abnormality determination. In addition, the control substrate 140 as a controller saves the abnormality log in the FROM 120 as a non-volatile semiconductor storage device in accordance with the generation of the abnormality log.

[0095] Thus, even if the magnetic head 104 , magnetic disk 100 , SPM 101 , motor driver IC 109 , head IC 105 , etc. are damaged due to abnormal physical influence on the magnetic disk device 1 and the abnormal log stored in the magnetic disk 100 cannot be read, the abnormal log can be obtained from the FROM 120 .

[0096] Furthermore, even if any of the above-mentioned components is damaged and the abnormality log in the RAM 121 is lost before the abnormality log stored in the RAM 121 is written to the magnetic disk 100 , an abnormality log with the same contents can be obtained from the FROM 120 .

[0097] This improves the convenience of the magnetic disk device 1.

[0098] In the above description, the CPU 108 determines the trigger for generating an abnormality log based on both the detection value of the impact sensor 110 and the detection value of the RV sensor 111. The trigger for generating an abnormality log may be determined based on only one of the detection value of the impact sensor 110 and the detection value of the RV sensor 111.

[0099] The period (Duration) during which the detection value of the impact sensor 110 or the detection value of the RV sensor 111 continuously exceeds the limit value exceeds D1 is used as a trigger for generating an abnormality log. The trigger for generating an abnormality log is not limited to this.

[0100] In addition, the abnormal log includes Duration, the maximum value of the detection value, the cumulative value of the detection value in Duration, the time when the maximum value is detected in Duration, or the waveform of the detection value. These information constituting the abnormal log are examples. The abnormal log can replace part or all of this information with the detection value of other sensors, and the numerical information obtained by processing the detection value of other sensors.

[0101] (Second embodiment)

[0102] In the first embodiment, an abnormality log is generated at a timing based on the detection values ​​of the impact sensor 110 and the RV sensor 111 and is stored in the FROM 120. Various modifications can be made as conditions for generating the abnormality log. In the second embodiment, an example of generating an abnormality log based on the detection value of the voltage sensor 112 is described. In addition, in the following embodiments, only matters different from the first embodiment are described, and the description of matters similar to the first embodiment is omitted.

[0103] Figure 8 This is a flowchart for explaining an example of the operation of acquiring the detection value of the sensor and determining the abnormality according to the second embodiment.

[0104] When a servo interruption occurs (S401), the CPU 108 obtains the detection values ​​of various sensors (S402). Then, the CPU 108 determines whether the detection value of the voltage sensor 112 exceeds the limit value S3 (S403). S3 is a limit value to be compared with the detection value of the voltage sensor 112 and is set in advance.

[0105] When the detection value of the voltage sensor 112 exceeds the limit value S3 (S403: Yes), the CPU 108 generates an abnormal log and immediately saves the generated abnormal log to the FROM 120 and the RAM 121 (S404). The abnormal log includes the detection value of the voltage sensor 112. In addition to the detection value of the voltage sensor 112, the abnormal log may also include numerical information obtained by processing the detection value of the voltage sensor 112, the detection value of other sensors, or numerical information obtained by processing the detection value of other sensors.

[0106] When the detection value of the voltage sensor 112 does not exceed the limit value S3 ( S403 : NO), or after the process of S404 , the control returns to S401 .

[0107] The abnormality log stored in RAM 121 is Figure 6 The abnormality log stored in FROM120 is written to disk 100 by the operation shown. Figure 7 Read out the actions shown.

[0108] In this way, the control substrate 140 may be configured to generate an abnormality log based on the detection value of the voltage sensor 112 that detects the voltage of the power supplied to the magnetic disk device 1 .

[0109] (Third embodiment)

[0110] In the third embodiment, an example in which the abnormality log is generated based on the detection value of the air pressure sensor 113 will be described.

[0111] Fig. 9 This is a flowchart for explaining an example of the operation of acquiring detection values ​​of the sensor and determining abnormality according to the third embodiment.

[0112] When a servo interruption occurs (S501), the CPU 108 obtains the detection values ​​of various sensors (S502). Then, the CPU 108 determines whether the detection value of the air pressure sensor 113 exceeds the limit value S4 (S503). S4 is a limit value to be compared with the detection value of the air pressure sensor 113 and is set in advance.

[0113] When the detection value of the air pressure sensor 113 exceeds the limit value S4 (S503: Yes), the CPU 108 generates an abnormal log and immediately saves the generated abnormal log to the FROM 120 and the RAM 121 (S504). The abnormal log includes the detection value of the air pressure sensor 113. In addition to the detection value of the air pressure sensor 113, the abnormal log may also include numerical information obtained by processing the detection value of the air pressure sensor 113, the detection value of other sensors, or numerical information obtained by processing the detection value of other sensors.

[0114] When the detection value of the air pressure sensor 113 does not exceed the limit value S4 ( S503 : NO), or after the process of S504 , the control returns to S501 .

[0115] As in the second embodiment, the abnormality log stored in the RAM 121 is Figure 6 The abnormality log stored in FROM120 is written to disk 100 by the operation shown. Figure 7 Read out the actions shown.

[0116] In this way, the control substrate 140 may be configured to generate an abnormality log based on the detection value of the air pressure sensor 113 that detects the air pressure.

[0117] (Fourth embodiment)

[0118] In the fourth embodiment, an example in which the generation of an abnormality log is executed based on the detection value of the temperature sensor 114 will be described.

[0119] Fig.10 This is a flowchart for explaining an example of the operation of acquiring detection values ​​of the sensor and determining abnormality according to the fourth embodiment.

[0120] When a servo interruption occurs (S601), the CPU 108 obtains the detection values ​​of various sensors (S602). Then, the CPU 108 determines whether the detection value of the temperature sensor 114 exceeds the limit value S5 (S603). S5 is a limit value to be compared with the detection value of the temperature sensor 114 and is set in advance.

[0121] When the detection value of the temperature sensor 114 exceeds the limit value S5 (S603: Yes), the CPU 108 generates an abnormal log and immediately saves the generated abnormal log to the FROM 120 and the RAM 121 (S604). The abnormal log includes the detection value of the temperature sensor 114. In addition to the detection value of the temperature sensor 114, the abnormal log may also include numerical information obtained by processing the detection value of the temperature sensor 114, the detection value of other sensors, or numerical information obtained by processing the detection value of other sensors.

[0122] When the detection value of the temperature sensor 114 does not exceed the limit value S5 ( S603 : NO), or after the process of S604 , the control returns to S601 .

[0123] As in the second embodiment, the abnormality log stored in the RAM 121 is Figure 6 The abnormality log stored in FROM120 is written to disk 100 by the operation shown. Figure 7 Read out the actions shown.

[0124] In this way, the control substrate 140 may be configured to generate an abnormality log based on the detection value of the temperature sensor 114 that detects the temperature.

[0125] In addition, any two or more of the first to fourth embodiments can be combined. For example, the opportunity described in two or more of the first to fourth embodiments can be used as the opportunity to generate an abnormality log by logically ORing or logically ANDing. In other words, the controller can generate an abnormality log based on the detection value of the sensor.

[0126] As described above, according to the first to fourth embodiments, the magnetic disk device includes a sensor, a nonvolatile semiconductor storage device, and a controller. The sensor detects the degree of physical influence received from the outside. The controller generates a log when the detection value of the sensor satisfies the condition for abnormality determination, and saves the log to the semiconductor storage device in accordance with the generation of the log.

[0127] Thus, even if the abnormality log stored in the disk cannot be accessed or the disk device fails before the generated abnormality log is saved to the disk, the abnormality log can be read from the nonvolatile semiconductor storage device, thereby improving the convenience of the disk device.

[0128] In addition, the controller may also be configured to save information corresponding to the detection value in a non-volatile semiconductor storage device based on the detection value of the sensor. The information corresponding to the detection value may be the detection value, or may be all or part of the information cited as an example of an abnormality log. That is, in the first to fourth embodiments, an example is described in which the controller generates information corresponding to the detection value such as an abnormality log and saves the information in a non-volatile semiconductor storage device without leaving a time interval. The above information may also be saved in a non-volatile semiconductor storage device at an arbitrary timing after being generated.

[0129] In this case, if the magnetic disk device 1 fails during the period from when the abnormal log is generated to when the abnormal log is saved in the nonvolatile semiconductor storage device, the abnormal log cannot be obtained. However, after the abnormal log is saved in the nonvolatile semiconductor storage device, even if a failure occurs that makes it impossible to access the magnetic disk 100, the abnormal log can be obtained from the nonvolatile semiconductor storage device.

[0130] 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 novel embodiments can be implemented in various other ways, and various omissions, substitutions, and changes can be made without departing from the scope of the subject matter of the invention. These embodiments and their variations are included in the scope and subject matter of the invention, and are included in the invention described in the claims and their equivalents.

Claims

1. A magnetic disk device comprising: disk; A magnetic head for performing writing and reading relative to the magnetic disk; Sensors, which detect the extent of physical impact from the outside; Non-volatile semiconductor memory devices; and The controller generates a log when the detection value of the sensor satisfies a condition for abnormality determination, and stores the log in the semiconductor storage device in response to the generation of the log. The condition is that the magnitude of the detection value of the sensor exceeds the first value continuously for a duration exceeding the second value. The sensor is a shock sensor or a rotational vibration sensor.

2. The magnetic disk device according to claim 1, The log includes at least one of the duration, a maximum value of the magnitude of the detection value of the sensor in the duration, a cumulative value of the detection value of the sensor in the duration, a time at which the maximum value is detected in the duration, and a waveform of the detection value of the sensor.

3. A magnetic disk device comprising: Sensors, which detect the extent of physical impact from the outside; Non-volatile semiconductor memory devices; and The controller stores information corresponding to the detection value in the semiconductor storage device based on the detection value of the sensor when the detection value of the sensor continuously exceeds the first value for a duration exceeding a second value. The sensor is a shock sensor or a rotational vibration sensor.

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