JP2003141702A - Disk storage and write control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a disk storage capable of automatically prohibiting a write operation in which a host system is not involved under a temperature environment equal to or less than a low-temperature limit. SOLUTION: A CPU 10 automatically prohibits the write operation in the case of the low-temperature limit or less accompanying magnetic recording properties on the basis of a temperature value from a temperature sensor 12 during a write operation mode in which the host system 20 is not involved. The CPU 10 temporarily stores recording data relating to the write operation into a flash memory 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to a disk storage device for magnetically recording data on a disk medium, and more particularly to a disk storage device having a write operation mode other than a normal write operation.

[0002]

2. Description of the Related Art Conventionally, a disk storage device (hereinafter, also referred to as a disk drive) such as a magnetic disk device or a magneto-optical disk device magnetically records data on a disk which is a recording medium. It is configured to restore the magnetically recorded data to the original data from the disc.

By the way, the disk drive is widely used not only as a storage device for a conventional personal computer but also as a data storage device for various digital devices mounted on a digital television or an automobile. . For this reason, in the operating environment of the disk drive accompanying the installation of digital equipment, technical measures are required especially for the temperature environment.

Normally, in order to ensure a certain level of reliability, the temperature range in which the disk drive can operate normally is
It is preset as product specifications. In a disk drive, since data is magnetically recorded on the disk, the recording characteristics (write operation characteristics) at low temperatures are important. Generally, in the field of magnetic recording technology, the coercive force of a disk increases as the temperature decreases. For this reason,
It has been confirmed that when the temperature becomes extremely low, the magnetic recording capability of the write head is exceeded and magnetic recording by magnetization reversal on the disk becomes difficult. Therefore, in the temperature range as the product specification, the temperature value of the operation limit on the low temperature side is specified based on the recording characteristics related to the write operation.
In the read operation of reading data from the disc,
The allowable operating range on the low temperature side is wider than the write operation. Further, the temperature value of the operation limit on the high temperature side is determined depending on the read / write operation characteristics as well as the operation characteristics of the components of the disk drive.

[0005]

In the disk drive, temperature specifications relating to the read / write operation are set based on the magnetic recording characteristics especially at low temperatures. In a low temperature environment exceeding the allowable range of temperature specifications, there is a high possibility that sufficient reliability for recorded data cannot be ensured, especially when a write operation for recording data on a disc is executed. Therefore, conventionally, a technique has been developed or proposed in which the temperature inside the drive is monitored by a temperature sensor and a write operation is prohibited when a change in low temperature exceeding an allowable range occurs (for example, Japanese Patent Laid-Open No. 7- (See Japanese Patent No. 6560).

According to such a prior art, it is possible to avoid the situation where user data having low reliability is recorded on the disk even when the temperature fluctuation below the low temperature limit occurs.
However, in the disk drive, in addition to the normal write operation, there is a write operation mode in which the host system does not participate (regardless of issuance of a write command). Specifically, there are a ride operation accompanying the alternative processing when a read error occurs, a write operation for recording or updating history information related to the operation history when the drive is started, and the like.

Since the host system is involved in the normal read / write operation, when a temperature fluctuation below the low temperature limit occurs, the host system stops issuing the write command and issues only the read command. It is possible to However, since the host system cannot be controlled in the write operation mode, the write operation is executed in a temperature environment below the low temperature limit. Therefore, data or history information for which sufficient reliability cannot be ensured is recorded on the disk, and in the worst case, the data or information may be lost.

Therefore, an object of the present invention is to improve the reliability of data recording by automatically prohibiting a write operation which is not particularly related to the host system in a temperature environment below the low temperature limit. To provide a disk storage device.

[0009]

In view of the present invention, in order to ensure the reliability of magnetic data recording at a low temperature, a write operation mode in which the host system side is not particularly involved (recording operation when a write command is not issued) Then, the present invention relates to a write control technology that realizes a function of automatically prohibiting a write operation in a temperature environment below a low temperature limit.

A disk storage device according to the aspects of the present invention comprises:
What is a disk medium for magnetically recording data, a read / write means for performing a data read operation or a data write operation on the disk medium, a temperature sensor for detecting a temperature, and a write command from a host system Regardless of this, the control means for prohibiting the write operation is provided when the temperature value detected by the temperature sensor in the write operation mode for recording data on the disk medium is less than a specified value.

With such a configuration, when the temperature in the operating environment of the device changes below the low temperature limit, the write operation mode not involving the host system can be automatically prohibited. Therefore, in a temperature environment below the low temperature limit, for example, data recording associated with a substitute process at the time of a normal read operation and data recording such as history information executed for starting the device can be avoided in advance. Therefore, as a result, it is possible to secure sufficient reliability with respect to data recording in which the host system is not involved.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

(Structure of Disk Drive) FIG. 1 is a block diagram showing a main part of the disk drive in the embodiment.

The disk drive of the embodiment is assumed to be a hard disk drive (HDD) using the disk 1 as a magnetic recording medium. This drive has a magnetic head 2 for performing a data read / write operation on a disk 1. The disk 1 is fixed to a spindle motor (SPM) 3 and is rotated at high speed. The magnetic head 2 is mounted on an actuator 4 driven by a voice coil motor (VCM) 5. VCM5
Is a VCM driver 6 included in the motor driver IC 6.
A drive current is supplied by 0. Motor driver IC6
Includes an SPM driver 61 together with a VCM driver 60 and is controlled by the CPU 10.

Here, the magnetic head 2 has a structure in which a read head for performing a read operation and a write head for performing a write operation are mounted on a slider. The actuator 4 is driven and controlled by a servo system having the CPU 10 as a main element to position the magnetic head 2 at a target position on the disk 1.

In addition to such a head / disk assembly, the disk drive includes a preamplifier circuit 7 and an R /
W channel 8 and disk controller (HDC) 9
And a circuit system having a CPU 10 and a memory 11.

The preamplifier circuit 7 has a read amplifier and a write amplifier for amplifying the read signal output from the read head. The write amplifier converts the write data signal output from the R / W channel 8 into a write current signal and sends it to the write head. R / W channel 8
Read / write data signal (including servo data signal)
Is a signal processing IC for processing the. The HDC 9 has an interface function between the drive and the host system 20 (for example, a personal computer or a digital device).

The CPU 10 is the main controller of the drive, and executes the control operation of the servo system, the normal read / write operation control, and the control of the write operation mode not involving the host system 20 related to the embodiment. The memory 11 includes a RAM and a ROM in addition to the flash memory (EEPROM) 110 which is a non-volatile memory.
And stores various data and programs necessary for controlling the CPU 10.

Further, the present drive has a temperature sensor 12 for detecting the temperature inside the drive. Temperature sensor 1
2 detects the temperature at a fixed sampling interval and outputs the temperature value to the CPU 10. The CPU 10 monitors the temperature fluctuation according to the temperature detection from the temperature sensor 12.

Note that, as shown in FIG. 3, the host system 20 can obtain the temperature value detected by the temperature sensor 12 from the disk drive 30 by issuing a predetermined command. The host system 20 may also have its own temperature sensor 200 and be configured to monitor changes in the ambient temperature of itself and the drive 30.

(Write Operation Mode Not Involved by Host System) In the embodiment, the drive operating environment is as follows:
As shown in FIG. 2, a temperature environment in an operable temperature range is assumed. In the temperature range, the high temperature limit value (TH) is, for example, about 55 degrees (Celsius), and the read /
It is set depending on the temperature characteristic of the drive components together with the write operation characteristic. On the other hand, the low temperature limit value differs between the read operation characteristic and the write operation characteristic. As described above, the low temperature limit value (TW) in the write operation is, for example, about 0 degree (Celsius) and is set depending on the low temperature characteristics of magnetic recording. In addition, the low temperature limit value (T
R) is, for example, about −20 degrees (Celsius), and has a relatively wide allowable range.

On the other hand, the disk drive has a write operation mode in which the host system 20 is not involved (a write operation without issuing a write command) other than the normal write operation in response to a write command from the host system 20. In this embodiment, the write operation mode is assumed to be a write operation associated with an alternative process that occurs during a normal read operation, and a write operation for recording history information regarding the operation history of the drive.

(Alternative Processing During Read Operation) The control method of the write operation associated with the alternative processing will be described below with reference to the flowchart of FIG.

The CPU 10 controls the positioning of the read head at a target position on the disk 1 in response to a read command from the host system 20 and executes a read operation for reading data from the target position (step S1). In the read operation, the read signal output from the read head is restored to the original data in the R / W channel 8 and HD
Transferred to C9. The HDC 9 performs an ECC (error detection / correction) process to check whether the data restored by the read operation includes a read error. If there is no read error, the read operation ends normally (NO in step S2).

On the other hand, when a read error occurs, the CPU
10 executes a retry operation including error correction processing by ECC processing (YES in step S2, S3). C
The PU 10 repeats the retry operation until the normal data is restored (the read error disappears) (step S
4). However, when the number of retries reaches a predetermined number (N) or more, the CPU 10 determines that the data cannot be restored and shifts to a predetermined abnormal process (NO in step S5).

When the data can be restored to normal data by the retry operation within the predetermined number (N), the CPU 10 executes a data reassignment process on the disk 1 called a substitution process (step S7). Note that the alternative process is re-assign process or reallocation (r
It is also called e-allocation) processing.

When a read error occurs, there is a possibility that the lead position on the disk 1 is defective or scratched. Therefore, by the alternative process, a more reliable area (physically different recording area)
The reliability of the recorded data is improved by moving the recorded data to. In this case, the alternative area designated by the alternative process is the alternative track in the track unit, and the alternative sector in the data sector unit. Further, in the alternative process, the recording area on the disk 1 is changed, so that it is necessary to update a management table (FAT: file allocation table) for managing addresses on the disk 1. The management table is normally stored in the system area (reference numeral 100 in FIG. 1) which is the outermost track (track 0) on the disc 1.

In short, although only the read command is issued from the host system 20, the disk drive executes the write operation (movement of user data and update of the management table) accompanying the alternative process. This write operation is a recording mode in which the host system 20 is not involved. At this time, the CPU 10 determines that the temperature sensor 1
Based on the detected temperature value from 2, it is determined whether or not the temperature value is equal to or lower than the low temperature limit value (TW) in the write operation shown in FIG. 2 (step S6).

If the temperature value is higher than the low temperature limit value (TW), the CPU 10 executes the above-mentioned alternative process and terminates the read operation normally (NO in step S6, S).
7). On the other hand, when the temperature value is a low temperature value equal to or lower than the low temperature limit value (TW), the CPU 10 ends the read operation normally without executing the alternative process (Y in step S6).
ES). In other words, the CPU 10 prohibits the write operation accompanying the alternative process and invalidates the alternative process.

As described above, according to the embodiment, in the write operation mode associated with the alternative process unrelated to the write command from the host system 20, the temperature is below the low temperature limit value (TW) depending on the magnetic recording characteristics. The write operation is prohibited under the temperature environment. Therefore, the data recording such as the movement of the user data and the update of the management table associated with the alternative process is not executed. Therefore, it is possible to avoid a situation in which data whose reliability is lowered due to a low temperature is recorded on the disk 1 without the host system 20 being involved.

(Modification) FIG. 5 is a flowchart showing a modification relating to the control of the write operation mode associated with the alternative process of the embodiment.

In this modification, the CPU 10 uses the temperature sensor 1
Based on the detected temperature value from 2, it is determined whether or not the temperature value is equal to or lower than the low temperature limit value (TW) in the write operation shown in FIG. 2 (step S15). If the temperature value is higher than the low temperature limit value (TW), the CPU 10 executes the alternative process and ends the read operation normally (NO in step S15, S16).

On the other hand, when the temperature value is a low temperature below the low temperature limit value (TW), the CPU 10 terminates the read operation normally without executing the alternative process (step S).
Yes of 15). At this time, the CPU 10 temporarily saves the record data (data relating to the movement of the user data and the update of the management table) associated with the alternative process in the nonvolatile flash memory 110, and ends normally (step S17). .

By such processing, instead of simply invalidating the alternative processing, it is possible to temporarily hold it and perform the alternative processing according to the occasion. That is, the write operation is enabled, and the alternative process can be executed by using the idle time other than the normal read / write operation. In general, even if the external temperature drops sharply, the internal temperature of the disk drive rises to some extent due to self-heating when power is maintained for a certain period of time or longer.
Further, in the case of a disk drive for a digital device mounted on an automobile or the like, it can be expected that the ambient temperature environment changes and the external temperature rises.

According to this modification, the CPU 10 prepares for an alternative process using the data stored in the flash memory 110 when the temperature value from the temperature sensor 12 becomes higher than the low temperature limit value (TW). Can be moved to. CPU1
In 0, the spare process other than the normal read / write operation is used to execute the alternative process, and after completion, the data stored in the flash memory 110 is erased. Therefore, in the case of this modification, it is possible to avoid a situation in which data whose reliability has deteriorated due to a low temperature is recorded, and it is possible to secure the recorded data necessary for the alternative process.

The process from step S11 to step S16 in FIG. 5 is the same as the process from step S1 to step S7 shown in FIG.

(History Information Recording Process) A method of controlling the write operation associated with the recording process of the history information regarding the operation history of the drive will be described below with reference to the flowchart of FIG.

In the disk drive, history information related to the operation history of the drive is stored in the disk 1 at the time of start-up immediately after the power is turned on or during an idle time other than normal read / write operation.
A write operation (update operation) for recording in the upper system area (area 100 of track 0) is being executed.
This write operation is a write operation mode in which the host system 20 is not involved.

The history information is, for example, information on the use of the drive such as the number of times the power is turned on and the number of alternative processes, and a predetermined standard such as the number of abnormal stops (for example, SMART standard).
It is the information specified in.

The CPU 10 starts the update data write operation relating to the update of the history information at the start-up immediately after the power is turned on or in the idle time other than the normal read / write operation (step S21). At this time, the CPU 10 determines the temperature value based on the temperature detection value from the temperature sensor 12 as shown in FIG.
It is determined whether or not the temperature is equal to or lower than the low temperature limit value (TW) in the write operation shown in (S22).

If the temperature value is higher than the low temperature limit value (TW), the CPU 10 executes the write operation, updates the history information, and terminates normally (N in step S22).
O, S23). On the other hand, the temperature value is the low temperature limit value (TW)
In the case of the following low temperature, the CPU 10 terminates normally without executing the write operation (YE in step S22).
S). Here, the CPU 10 may temporarily store the update data regarding the update of the history information in the flash memory 110 (step S24).

As described above, in the write operation mode accompanying the recording (updating) process of the history information unrelated to the write command from the host system 20, the temperature below the low temperature limit value (TW) depending on the magnetic recording characteristics. Under the environment, the write operation is prohibited. Therefore, it is possible to avoid a situation where data whose reliability is lowered due to a low temperature is recorded on the disk 1 without the host system 20 being involved.

By temporarily storing the update data regarding the update of the history information in the flash memory 110, the write operation can be restarted when the temperature environment is improved for the same reason as described above. Becomes

In the embodiment, the host system 2
As a write operation mode in which 0 is not involved, a write operation accompanying an alternative process and a record process (update process) of history information is assumed. However, the write operation mode is not limited to this, and the disc itself is automatically determined by the drive itself. All write operations for recording data to are included.

The temperature sensor 12 may be installed either on the circuit board mounted outside the disk drive or on the circuit board installed inside the drive. Further, as shown in FIG. 3, by using the temperature detection value from the temperature sensor 200 provided in the host system 20, C
The configuration may be such that the PU 10 determines the temperature condition inside the drive.

[0046]

As described in detail above, according to the present invention, in a temperature environment below the low temperature limit related to magnetic recording characteristics,
In particular, the write operation that does not involve the host system is automatically prohibited. Therefore, since it is possible to avoid the unreliable data recording on the disc due to the low temperature environment, it is possible to provide the disc storage device capable of improving the reliability of the data recording.

[Brief description of drawings]

FIG. 1 is a block diagram showing a main part of a disk drive according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining temperature characteristics of a read / write operation according to the same embodiment.

FIG. 3 is a block diagram for explaining a modification of the embodiment.

FIG. 4 is a flowchart for explaining a write control procedure at the time of alternative processing according to the embodiment.

FIG. 5 is a flowchart for explaining a write control procedure in a modified example at the time of alternative processing according to the same embodiment.

FIG. 6 is a flowchart for explaining a write control procedure when recording history information according to the embodiment.

[Explanation of symbols]

1 ... Disc 2 ... Magnetic head 3 ... Spindle motor (SPM) 4 ... Actuator 5 ... Voice coil motor (VCM) 6 ... Motor driver IC 7 ... Preamplifier circuit 8 ... R / W channel 9 ... Disk controller (HDC) 10 ... CPU 11 ... Memory 12 ... Temperature sensor 20 ... Host system 110 ... Flash memory 200 ... Temperature sensor

Claims (13)

[Claims] 1. A disk medium for magnetically recording data, a read / write means for performing a data read operation or a write operation on the disk medium, a temperature sensor for detecting a temperature, and an external device. Irrespective of the write command, the control means for prohibiting the write operation when the temperature value detected by the temperature sensor is equal to or lower than a specified value in the write operation mode for recording data on the disk medium. A disk storage device characterized by the above. 2. The write operation mode is a write operation in an alternative process that accompanies a read error when a read operation is executed in response to a read command from the outside. The disk storage device described in 1. 3. The write operation mode is a write operation for recording predetermined information in a predetermined area on the disk medium during a period excluding an execution period of a normal read operation or a write operation. The disk storage device according to claim 1. 4. The control means includes means for prohibiting a write operation when the temperature value is equal to or lower than a specified value and temporarily storing data to be recorded on the disk medium in a memory. The disk storage device according to claim 1, wherein the disk storage device is a storage device. 5. The control means, when the temperature value is equal to or lower than a specified value, suspends the alternative process involving a write operation and temporarily stores data to be recorded on the disk medium in a memory. The disk storage device according to claim 2, further comprising storage means. 6. The control means prohibits a write operation when the temperature value is equal to or lower than a specified value, and temporarily stores predetermined information to be recorded in a predetermined area on the disk medium in a memory. 4. The disk storage device according to claim 3, further comprising means. 7. The write operation mode is a write operation for recording or updating information about an operation history of the device in a predetermined area on the disk medium when the device is activated. The disk storage device described in 1. 8. A write control method applied to a disk storage device for magnetically recording data on a disk medium, the write operation recording data on the disk medium regardless of a write command from the outside. In the mode, a write control method comprising a step of acquiring a temperature value detected by a temperature sensor, and a step of inhibiting a write operation in the write operation mode when the temperature value is equal to or less than a specified value. . 9. A write control method applied to a disk storage device for magnetically recording data on a disk medium, comprising: performing a read operation for reading data from the disk medium; A step of performing a retry operation in response to the occurrence of a read error, a step of acquiring a temperature value detected by a temperature sensor at the time of executing a write operation accompanying an alternative process after the retry operation, and the temperature value Is less than or equal to a specified value, the write control method comprises the step of inhibiting the write operation. 10. A write control method applied to a disk storage device for magnetically recording data on a disk medium, wherein the predetermined information is provided during a period excluding an execution period of a normal read operation or write operation. In a write operation mode for recording in a predetermined area on the medium, a step of acquiring a temperature value detected by a temperature sensor, and if the temperature value is equal to or lower than a specified value, write operation in the write operation mode is performed. A light control method comprising a prohibiting step. 11. The method according to claim 9, wherein in the step of inhibiting the write operation, data to be recorded on the disk medium in accordance with the alternative process is temporarily stored in a memory. Disk storage device. 12. The disk storage device according to claim 10, wherein in the step of inhibiting the write operation, predetermined information to be recorded on the disk medium is temporarily stored in a memory. 13. The write operation mode is a write operation for recording or updating information regarding an operation history of the device in a predetermined area on the disk medium when the device is activated. The disk storage device described in 1.