JPH09297659A - Non-volatile storage device and control method for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive, high-reliability and highperformance non- volatile storage device by integrating a hard disk drive and a semiconductor disk drive. SOLUTION: An integrated drive unit 7 is one drive unit to allocate a single drive number, the storage area of a flash memory 6 to be used as the semiconductor disk drive is used as a 1st storage area at one part among all the storage areas of the integrated drive unit 7, and the storage areas of a hard disk drive 5 having storage capacity more than that of the flash memory 6 are used for the remaining 2nd storage areas. Therefore, since these hard disk drive 5 and flash memory 6 are handled as different storage areas inside one integrated drive unit 7, a CPU 1 can selectively access the storage area of the hard disk drive 5 and the storage area of the flash memory 6 with the single drive number.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to a non-volatile memory device used as a next memory and a control method thereof, and more particularly to a non-volatile memory device improved so that different types of disk devices can be combined and a control method thereof.

[0002]

2. Description of the Related Art Generally, in a computer system, a non-volatile storage device is used as its secondary storage. A hard disk drive is known as one of the magnetic storage devices among the nonvolatile storage devices.
In this method, a disk (disk) having a magnetic surface is magnetized according to data to store the data. In order to magnetize the disk and read the magnetized data, a magnetic recording head, such as a record needle in a record player, is provided. By rotating the disk and moving the magnetic head to a position corresponding to the storage address, data is stored at an externally specified address or data at an externally specified address is read. Since this hard disk device is inexpensive and has a large capacity, it is widely used as a secondary storage device of a computer.

However, since the hard disk drive mechanically moves the magnetic head to an address designated from the outside, the data writing and reading speeds are slow. Further, when the magnetic head comes into contact with the disk with an excessive pressure due to external vibration, the disk is scratched and the so-called disk is destroyed. In addition, there is a problem that a motor for rotating the disk is required and power consumption is large.

A flash memory is known as one of the non-volatile memory devices for electrically storing data.
This electrically stores data in a memory cell in which a charge storage layer and a control gate are stacked on a semiconductor substrate. The charge storage layer is normally insulated, and when a high voltage is applied between the semiconductor substrate and the control gate, for example, a current called a tunnel current flows between the semiconductor substrate and the charge storage layer. This controls the amount of charge in the charge storage layer to store data. Data is read by detecting the charge amount of the charge storage layer. A plurality of memory cells are arranged in a matrix, and by electrically specifying a row address and a column address, data is written in, erased from, or read out from the memory cell at an arbitrary address.

A semiconductor disk device using such a flash memory operates at high speed because it is controlled by an electric signal. It is also resistant to external vibration and consumes less power. However, the price per unit storage capacity is high. Further, the flash memory has a limit on the number of rewrites, and the number of rewritable times per memory cell is 1.
It is about, 000,000 times.

In many computers, both a hard disk drive and a flash memory can be used, but each is used as a separate drive unit. Conventional central processing unit 1 (C
PU) and the configuration of the non-volatile memory device are shown in FIG.

In FIG. 9, a floppy disk drive 4, a hard disk drive 5, and a flash memory 6 are used as a non-volatile storage device. Each non-volatile storage device is, for example, a drive A, C, D
The storage address of the selected drive unit is selected by the address signal of the address bus 2.
Data is exchanged between each drive unit and the CPU 1 via the data bus 3.

The hard disk drive 5 and the floppy disk drive 4 are built in the computer body, and the flash memory 6 is used as a PC card inserted into a PC card slot. The CPU 1 and the non-volatile storage devices 4, 5 and 6 are directly connected, but may be connected via some sub-control device.

The hard disk drive 5 which is inexpensive and has a large capacity is used as a main non-volatile storage device and stores system files and many application software. When the computer is started up or the application software is started up, it is preferable from the viewpoint of speed that the flash memory 6 is used. Some of the large application software are used at the time of startup or are frequently used, and some are rarely used. In this case, it is desirable to store in the flash memory 6 a portion that is used or frequently used at startup, and a portion that is used less frequently in the hard disk 5.

However, in the past, since the hard disk 5 and the flash memory 6 are completely separate drive units having different drive numbers, it is difficult in terms of data management to store one piece of software across these drive units.

[0011]

As described above, the conventional nonvolatile memory device has the problems that the speed is slow, the power consumption is large, and the shock resistance is low when the magnetic memory device such as the hard disk drive is used. It was In addition, using nonvolatile semiconductor devices such as flash memory is expensive.
There was a problem that the number of rewrites was limited. Further, since the magnetic storage device and the non-volatile semiconductor device are realized as separate drive units, separate data management is required, and it is practically difficult to store one piece of software across the drive units.

The present invention has been made in view of the above points, and a magnetic storage device such as a hard disk drive and a non-volatile semiconductor device such as a flash memory are integrated so as to make up for each other's defects, and at a low cost. An object of the present invention is to provide a highly reliable and high performance nonvolatile memory device and a control method thereof.

[0013]

According to the present invention, in a non-volatile memory device to which a single drive number is assigned and designated by the drive number, a first memory area within the entire memory area of the non-volatile memory device is provided. And a semiconductor disk device composed of a non-volatile semiconductor memory device in which data can be electrically erased and written, and a first memory area other than the first memory area in the entire memory area of the non-volatile memory device. A magnetic disk device to which two storage areas are allocated, and the first drive is provided with a single drive number.
The storage area and the second storage area are selectively accessible.

In this non-volatile storage device, a semiconductor disk device such as a flash memory and a magnetic disk device such as a hard disk are provided together in one drive unit to which a single drive number is assigned. The storage area of the device is used as a first storage area which is a part of the entire storage area of the non-volatile storage device, and the remaining second storage area is the storage area of the magnetic disk device. Therefore, since the semiconductor disk device and the magnetic disk device are treated as different storage areas in one drive unit, the host system uses the single drive number to identify the first storage area of the semiconductor disk and the second storage area of the magnetic disk device. Can be selectively accessed. Therefore, it is possible to integrate the semiconductor disk device and the magnetic disk device, thereby making it possible to compensate for the defects of the semiconductor disk device and the magnetic disk device, and to manage each data of the semiconductor disk device and the magnetic disk device by one disk. Since it can be performed in the same manner as a drive, a low-cost, highly reliable, high-performance nonvolatile memory device can be realized.

In this case, when one piece of software is stored across the semiconductor disk device and the magnetic disk device, a file used at the time of starting the program is stored in the semiconductor disk device having a high data read speed, and the file is stored. It is preferable to store other files besides the above in the magnetic disk device. As a result, the program can be started up at high speed. Further, whether to store the file in the semiconductor disk device or the magnetic disk device may be determined according to the frequency of use of the file.

Further, a control means for integrally controlling the semiconductor disk device and the magnetic disk device is further provided, and the control means is used to determine the type of file, the frequency of use of the file, the free space of the first and second storage areas, and the like. It is preferable that the file to be moved is determined and the file can be moved between the first storage area and the second storage area. This allows, for example, moving frequently used files from the second storage area to the first storage area,
If the free space of the first storage area is small and the second storage area has a sufficient free space even for a file used at startup, the file is transferred from the first storage area to the second storage area.
It becomes possible to move to the storage area.

In the present invention, the data management information for managing the data storage position of each of the file group stored in the first storage area and the file group stored in the second storage area is used. Since it is high, it is basically stored in the first storage area, but when the number of times of rewriting the data management information increases, it is automatically moved from the first storage area to the second storage area by the control means. It is configured to be. As a result, it is possible to speed up the disk access while solving the problem due to the limitation on the number of rewrites of the semiconductor disk device.

Further, the present invention is a non-volatile memory device to which a single drive number is assigned and designated by the drive number, wherein the first memory area within the entire memory area of the non-volatile memory device is assigned. And a semiconductor disk device composed of a nonvolatile semiconductor memory device capable of electrically erasing and writing data, and a second memory other than the first memory region in the entire memory region of the nonvolatile memory device. A method for controlling a non-volatile storage device, comprising: a magnetic disk device to which an area is allocated, wherein the non-volatile storage device is designated as a write target in response to a write request designating a drive number of the non-volatile storage device. The type of the file to be written, and the file to be written is set to the first storage area and the second storage according to the detection result. And determining whether to store in either frequency band.

This control method is realized, for example, as an external control by software such as a file system or a disk driver, or an internal control by a control means in a non-volatile storage device, and is designated as a write target. Which of the first storage area and the second storage area the file to be written is stored is determined according to the type of the created file. Therefore, if a file that is frequently used or a file that is used when the program is started among files that compose a certain program is a write target file, the first
By storing in the storage area, it is possible to efficiently utilize the characteristic of the semiconductor disk device that high-speed access is possible. Further, attribute information for explicitly designating whether to store the file in the first storage area or the second storage area is added to the identifier of the file to be written,
The file to be written may be determined to be stored in the first storage area or the second storage area based on the attribute information. This makes it possible to explicitly use the semiconductor disk device and the magnetic disk device separately.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a central processing unit 1 (CPU) in a computer as a system configuration example using a nonvolatile storage device according to an embodiment of the present invention.
And the non-volatile storage devices 4, 5, and 6 are schematically shown. Here, the floppy disk drive 4 having a small capacity and a slower speed than the hard disk drive 5 is provided as an independent drive unit, but the hard disk 5 and the flash memory 6 have one advantage so as to complement each other's drawbacks. It is realized as an integrated drive unit 7 to which drive numbers are assigned.

The floppy disk drive 4 and the integrated drive unit 7 are, for example, drives A and C, respectively.
The storage address of the selected drive unit is selected by the address signal of the address bus 2.
Data is exchanged between each drive unit and the CPU via the data bus 3. Illustration of other control signal lines is omitted. Both the floppy disk drive 4 and the integrated drive unit 7 are built in the computer.

Although the CPU 1, the floppy disk drive 4, and the integrated drive unit 7 are directly connected here, they may be connected via some sub-control device.

The integrated drive unit 7 is one drive unit to which a single drive number is assigned,
The storage area of the flash memory 6 used as a semiconductor disk drive is used as a first storage area which is a part of the total storage area of the integrated drive unit 7, and the remaining second storage area is larger than the flash memory 6. The storage area of the hard disk drive 5 having a storage capacity is used. Therefore, the hard disk drive 5 and the flash memory 6 are designated by the same drive number, and the integrated drive unit 7
In this case, the CPU 1 can selectively access the storage area of the hard disk drive 5 and the storage area of the flash memory 6 with a single drive number.

Therefore, the hard disk drive 5 and the flash memory 6 can be integrated so that the respective defects of the hard disk drive 5 and the flash memory 6 can be compensated for, and the data management of the hard disk drive 5 and the flash memory 6 can also be performed. Since it can be performed in the same manner as one disk drive, a low-cost, highly reliable, high-performance nonvolatile memory device can be realized.

In this case, for example, when one piece of software is stored across the hard disk drive 5 and the flash memory 6, the flash memory 6 having a high data reading speed stores a file used when the program is started. Other files other than that file are stored in the hard disk drive 5 having a large storage capacity. As a result, the program can be started up at high speed. Further, by storing frequently used files in the flash memory 6 as much as possible, it becomes possible to speed up the average file reading speed and the like.

FIG. 2 shows an example of a concrete structure of the integrated drive unit 7. The integrated drive unit 7 includes a hard disk drive 5, a flash memory 6, a hard disk controller 8, a flash memory controller 9, and a hybrid controller 10.

In this integrated drive unit 7,
Address bus 2 and data bus 3 of the computer system
Is connected to a hybrid controller 10 that integrally controls the flash memory 6 and the hard disk drive 5. The hybrid controller 10 and the hard disk controller 8 are connected by a hard disk address bus 15 for transmitting storage address information and a hard disk data bus 16 for exchanging data. Illustration of other control signals is omitted.

The hard disk controller 8 and the hard disk drive 5 are connected by a hard disk address bus 17 for transmitting storage address information and a hard disk data bus 18 for exchanging data. Illustration of other control signals is omitted. The hybrid controller 10 and the flash memory controller 9 are connected to a flash memory address bus 11 for transmitting storage address information and a flash memory data bus 12 for exchanging data. Illustration of other control signals is omitted. The flash memory controller 9 and the flash memory 6 are connected by a flash memory address bus 13 for transmitting storage address information and a flash memory data bus 14 for exchanging data. Illustration of other control signals is omitted.

The flash memory controller 9 is a flash E capable of electrically erasing and writing data.
It emulates to control the flash memory 6 composed of EPROM to operate it as a semiconductor disk device, and receives the disk address (sector number, cylinder number, head) from the CPU 1 received via the hybrid controller 10. Address conversion for converting a memory address for a flash memory into a memory address for a flash memory, command conversion for converting a disk command (write, read) from the CPU 1 into a command for a flash memory (erase, write, read).

The hard disk controller 8 is for controlling mechanical mechanisms such as disks, motors and heads provided in the hard disk drive 5. The hard disk controller 8 is usually a part of the hard disk drive 5. It is provided as.

The hybrid controller 10 is a CPU
In response to a single drive number designated by 1, the hard disk controller 8 and the flash memory controller 9 are integratedly controlled, and are physically issued from the CPU 1 under the software control of a file system, a disk driver or the like. When the drive number is the drive number assigned to the integrated drive unit 7, in response thereto, the disk address and disk command from the CPU 1 are selectively passed to the hard disk controller 8 and the flash memory controller 9. Also,
The hybrid controller 10 is provided with functions such as management of storage areas of the hard disk drive 5 and the flash memory 6, management of frequency of use of files stored in each storage area, and transfer of files between storage areas. .

FIG. 3 shows an external view of the integrated drive unit 7. As shown in the figure, the integrated drive unit 7 is physically realized by one housing 50, and the mechanical mechanism portion of the hard disk drive 5 is housed in the housing 50, and the flash memory is provided on the mechanical mechanism portion. 6, a circuit board on which a plurality of flash EEPROMs 60, a flash controller 9, a hard disk controller 8, and a hybrid controller 10 are mounted is provided. Connection between the hybrid controller 10 and the outside is made by a plurality of terminals 19.

In FIG. 3, six flash EEPROM chips 60 and five terminals 19 are shown, but these may be provided as needed. The integrated drive unit 7 having such a structure is provided as a secondary storage inside the computer main body 20 as shown in FIG.

FIG. 5 shows an example of a data storage form in the integrated drive unit 7. The entire storage area of the integrated drive unit 7 is composed of a flash memory area stored in the flash memory 6 and a hard disk area stored in the hard disk drive 5. The flash memory area and the hard disk area are continuously allocated in the order of disk addresses. Whether to write data to the flash memory area or hard disk area is basically the type of file to be written, the frequency of use of the file, the number of times the flash memory area has been rewritten, the free space in each of the flash memory area and hard disk area, etc. Determined by

For example, as described above, when one piece of software is stored across the flash memory area and the hard disk area, only the execution file used when the program is started is stored in the flash memory area having a high data read speed. However, all files other than that file are stored in the hard disk area. In addition, frequently used files are stored in the flash memory area to improve system performance, and relatively infrequently used files are stored in a large hard disk area. Whether to write the file to be written to the flash memory area or the hard disk area is selected by an external specification such as a file system or a disk driver, or automatically within the integrated drive unit 7 under the control of the hybrid controller 10. be able to.

In the example of FIG. 5, config. The file called sys is stored in the flash memory area,
license02. The exe # is stored in the hard disk area. In addition, here, the file with “#” added to the end of the file identifier is stored in the hard disk area. "#" Is attribute information that explicitly indicates the hard disk area as the storage location of the file to be written. For a file with a file identifier with "#", for example, from the free area in the hard disk area, The storage location is selected, and the disk address indicating the storage location is sent from the CPU 1 to the hard disk controller 8 via the hybrid controller 10.

Further, even if a file once written in the flash memory area is not accessed for a long time, the hybrid controller 10 automatically moves the file from the flash memory area to the hard disk area. In this case, at the end of the identifier, f
ile02. Like txt (#), a "#" is implicitly attached to the file identifier of the moved file.
The meaning "implicitly" means that "#" is not recognized outside the integrated drive unit 7, but is recognized inside. In FIG. 6, () indicates the meaning of “implicitly”.

In addition, f moved to the hard disk area
ile02. When the access frequency of the file txt increases, the file is moved to the flash memory area by deleting the implicit "#".

File01. backup file file01.txt of a file called txt. Like "bak", backup files are stored in the hard disk area even if "#" is not added. When a certain amount of free space is left in the flash memory area and the remaining capacity of the flash memory area runs out, graph. A portion that cannot be stored in the flash memory area, such as a file called gph, is stored in the hard disk area. In this case, "1" indicating that the data is divided and stored is not stored in the flash. Implied at the end of the gph identifier. In addition, "# 2" is stored in the hard disk area. Implied at the end of the gph identifier.

If there is no remaining capacity in the flash memory area, even if the file specifies the flash memory area as the write location, all the files are stored in the hard disk area, and "#" is implicitly added to the end of the identifier. . "#" Is implicitly added to the free area of the hard disk area. The integrated free area of the integrated drive unit 7 is the sum of the free area of the flash memory area and the free area of the hard disk area.

FIG. 6 shows how to store the data management information. The data management information is for managing the data storage location of each of the files stored in the flash memory area and the files stored in the hard disk area, the free area, and the information necessary for accessing that file. Yes, for example, directory information or F
It is composed of AT information and the like. Specifically, in this data management information, the file name of the data stored in the flash memory area and the hard disk area, the storage address (including the information indicating whether it is the flash memory area or the hard disk area), the file creation date and time, the rewrite prohibition Whether or not it is managed. Since the data management information is frequently accessed, it is stored in the flash memory area as shown.

The data management information is rewritten when any one of the data is written, so that the number of times of rewriting is the largest. Generally, the flash memory has a limit of the number of times of rewriting. Therefore, when the data management information is rewritten frequently, or when the number of times of rewriting reaches a predetermined value, the flash memory is stored in the hard disk area as shown in FIG. Be moved.

Next, referring to the flowchart of FIG.
An example of a write control procedure for deciding whether to write the write target file in the flash memory area or the hard disk area will be described.

The file system and disk driver are
When receiving a file write request from a user program or the like, the disk address to store it is obtained based on the data management information of the disk drive corresponding to the drive number specified by the write request. In that case, the following processing is performed.

That is, first, the type of the file to be written is detected by using the file name, the file identifier, etc. of the file to be written, and the file is a file that is expected to be frequently used or a file for program startup. Whether or not there is checked (steps S11, S
12). Files that are expected to be used frequently,
If it is a file for program activation, the flash memory area is selected as the write destination (step S1)
4). Here, a predetermined empty area in the flash memory area is selected as a storage position based on the data management information corresponding to the flash memory area, and a disk number indicating the selected area together with a drive number designating the integrated drive unit 7. The address is sent from the CPU 1 to the integrated drive unit 7. As a result, the flash memory controller 9 and the flash memory 6 operate under the control of the hybrid controller 10, and the write target file is written in the designated storage location.

On the other hand, if the file to be written is not a file that is expected to be frequently used or a file for starting a program, the file identifier is #.
It is checked whether or not the file has been added (step S13). If the file has no # added, the flash memory area is selected as the write destination (step S14), and the same processing as described above is executed.

If # is added, the hard disk area is selected as the write destination (step S1).
5). Here, a predetermined empty area in the hard disk area is selected as a storage location based on the data management information corresponding to the hard disk area, and a drive number designating the integrated drive unit 7 and a disk address indicating the selected area are set. It is sent from the CPU 1 to the integrated drive unit 7. As a result, the hard disk controller 8 and the hard disk 5 operate under the control of the hybrid controller 10, and the write target file is written in the specified storage location.

As described above, according to this embodiment, the flash memory 6 and the hard disk drive 5 are provided together in one integrated drive unit 7 to which a single drive number is assigned. The storage area is used as a part of the total storage area of the integrated drive unit 7, and the storage area of the hard disk drive 5 is used as the remaining storage area. Therefore,
These flash memory 6 and hard disk drive 5
Are treated as different storage areas in one drive unit, the host system can selectively access the flash memory area and the hard disk area with a single drive number. Therefore, it is possible to integrate the semiconductor disk device and the magnetic disk device, thereby making it possible to compensate for the defects of the semiconductor disk device and the magnetic disk device, and to manage each data of the semiconductor disk device and the magnetic disk device by one disk. Since it can be performed in the same manner as a drive, a low-cost, highly reliable, high-performance nonvolatile memory device can be realized.

In the above description, the case where the flash memory area or the hard disk area to be used is selected by designation from the outside of the integrated drive unit 7 by software control has been described, but such a selection function is a hybrid. It can be realized by the controller 10, or by a sub-control device provided between the integrated drive unit 7 and the CPU 1.

In this embodiment, a hard disk drive is used as the magnetic disk device and a flash memory is used as the semiconductor disk device. However, a magneto-optical disk may be used instead of the hard disk, and an FRAM or the like may be used instead of the flash memory. Good.

[0051]

As described above, according to the present invention, the non-volatile semiconductor memory device and the magnetic memory device are integrally controlled, and the first memory area to be stored in the non-volatile semiconductor memory device is among all memory areas. The second storage area to be stored in the magnetic storage device is made a part of the storage area, and the second storage area is made to be the remaining portion of the entire storage area. A storage device is realized.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a computer system using a nonvolatile storage device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing an example of a specific configuration of the nonvolatile memory device according to the same embodiment.

FIG. 3 is a perspective view showing the external appearance of the nonvolatile memory device according to the same embodiment.

FIG. 4 is a perspective view showing the outer appearance of a portable computer in which the nonvolatile memory device of the same embodiment is mounted as a secondary memory device.

FIG. 5 is a diagram showing an example of a usage pattern of a storage area of each of the flash memory and the hard disk provided in the nonvolatile storage device of the same embodiment.

FIG. 6 is a diagram showing a second example of a usage pattern of the storage areas of the flash memory and the hard disk provided in the nonvolatile storage device of the same embodiment.

FIG. 7 is a diagram showing a third example of usage forms of the storage areas of the flash memory and the hard disk provided in the nonvolatile storage device of the same embodiment.

FIG. 8 is a flowchart showing an example of a write control procedure for determining which of a flash memory and a hard disk provided in the nonvolatile storage device of the embodiment to write a file to be written.

FIG. 9 is a block diagram showing the configuration of a computer system using a conventional nonvolatile memory device.

[Explanation of symbols]

1 ... Central processing unit, 2 ... Address bus, 3 ... Data bus, 4 ... Floppy disk drive, 5 ... Hard disk drive, 6 ... Flash memory, 7 ... Integrated drive unit, 8 ... Hard disk controller, 9 ... Flash memory controller, 10 ... Hybrid controller, 11 ... Address bus between hybrid controller and flash memory controller, 12 ... Data bus between hybrid controller and flash memory controller, 13 ... Address bus between flash memory controller and flash memory, 14 ... Flash memory controller and flash memory Data bus between, 15 ... Address bus between hybrid controller and hard disk controller, 16 ... Hybrid controller and hard disk controller Data bus between disk controller, 17 ... address bus between a hard disk controller and hard disk, 18 ... data bus between a hard disk controller and hard disk, 19 ... external terminals of integrated drive unit, 20 ... computer.

Claims (9)

[Claims] 1. A non-volatile storage device, to which a single drive number is assigned and designated by the drive number, wherein a first storage area in the entire storage area of the non-volatile storage device is assigned to electrically drive data. And a semiconductor disk device comprising a non-volatile semiconductor memory device capable of erasing and writing data, and the first disk in the entire memory area of the nonvolatile memory device.
A magnetic disk device to which a second storage area other than the storage area is assigned, and the first storage area and the second storage area can be selectively accessed with a single drive number. A non-volatile storage device characterized by being. 2. The first storage area is used for storing a file used at the time of starting a program in a file group constituting a program, and for storing a file other than the file, the first storage area is used. The non-volatile storage device according to claim 1, wherein two storage areas are used. 3. The first storage area is used for storing a frequently used file group, and the second storage area is used for storing a less frequently used file group. The non-volatile memory device according to claim 1. 4. A control means for integrally controlling the semiconductor disk device and the magnetic disk device is further provided, and the control means comprises a file type, a file usage frequency, and the first file.
And a file to be moved is determined based on at least one of the free capacities of the respective second storage areas, and the file is moved between the first storage area and the second storage area. The non-volatile storage device according to claim 1. 5. The first storage area includes data management information for managing the data storage positions of the file group stored in the first storage area and the file group stored in the second storage area. The nonvolatile storage device according to claim 1, wherein the nonvolatile storage device is stored. 6. A control unit for integrally controlling the semiconductor disk device and the magnetic disk device is further provided, and the control unit controls the data management based on the number of times of rewriting the data management information in the first storage area. The non-volatile storage device according to claim 5, wherein information is moved from the first storage area to the second storage area. 7. A non-volatile storage device, to which a single drive number is assigned and designated by the drive number, wherein a first storage area in the entire storage area of the non-volatile storage device is assigned and A semiconductor disk device composed of a nonvolatile semiconductor memory device capable of erasing and writing data, and a second memory area other than the first memory area in the entire memory area of the nonvolatile memory device are allocated. A method of controlling a non-volatile storage device comprising a magnetic disk device, wherein a file type specified as a write target in the write request in response to a write request specifying a drive number of the non-volatile storage device. Is detected, and the file to be written is assigned to either the first storage area or the second storage area according to the detection result. Control method characterized by determining whether the to. 8. The write target file is the first storage area when the write target file is a file that is frequently used or is a file that is used when the program is started in a file group that constitutes a program. The control method according to claim 7, wherein the file to be stored is determined. 9. The attribute information of the file to be written is added with attribute information that explicitly specifies in which of the first storage area and the second storage area the file should be stored. 8. The control method according to claim 7, wherein which of the first storage area and the second storage area is to store the file to be written is determined based on information.