JP2000112836A - Information processor, information storing method, and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an information processor capable of preventing flash disk management information from being lost at the time of reducing the capacity of power supply. SOLUTION: When the capacity of a battery or a dry cell is reduced and a possibility of destructing the contents of flash disk management information 8 is generated even when the information 8 is stored in a RAM 4, the contents are automatically written in a prescribed saving area of a flash ROM and saved. When power is restored again by charging or battery substitution and reset processing is started, the saved information 8 is read out and restored to a prescribed area of the RAM 4. Thereby, even when the information 8 is stored in the high speed readable/writable RAM 4, its contents are not destructed due to the reduction of power.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information processing apparatus, such as a portable information terminal, which is driven by a battery or a dry battery and uses a flash ROM for storing data, for example, as a disk device, an information storage method, and a storage medium. .

[0002]

2. Description of the Related Art In recent years, flash ROMs have been developed.
RO with flash ROM as price and capacity increase
Instead of M, a system that treats it as a disk device and builds a file system on it is realized. Flash ROMs generally have the following features. (1) Read (read) can be handled like a memory, but write (write) requires issuing a special command. (2) Writing cannot be performed until erasing (erasing) is performed once. (3) Erase is performed in erase block units (generally 64K
byte) or chip unit. (4) Erasure takes time (typically 1 second or longer). (5) The number of rewriting is limited (generally 100,000 times).

[0003] Because of these features, the following processing is performed when handled as a disk device. (A) Each erase block of the flash ROM is divided into block units (512 bytes, 10 bytes,
24 bytes). This block is called a real block. (B) Prepare a block conversion table that maps a virtual block (called a virtual block) as a disk device and a real block that can be viewed from higher-level software (such as an OS). (C) Prepare an erase block management table for managing the number of erases of each erase block, the actual block number included in each erase block, and the state of each actual block. The state of the real block is any of a free (writable state) / busy (a state where data is written and mapped to a virtual block) / garbage (a write disabled state without erasing). (D) In the block read process, the real block number is obtained from the virtual block number using the block conversion table, and the contents of the real block are read. (E) In the block write process, first, the real block number is obtained from the virtual block number using the block conversion table. At this time, the real block number cannot be obtained unless writing has been performed on the virtual block. In that case,
A real block in a free state is obtained from the erase block management table, and its contents are written to make the block busy. And
Write the actual block number to the block conversion table. When the real block number is obtained from the virtual block number by the block conversion table, the state of the real block in the erase block management table is changed from busy to garbage. A free block is obtained from the erase block management table, the contents are written, and the busy block is set. Then, the block conversion table is updated to a new real block number. (F) When the number of real blocks in the garbage state increases, garbage collection processing is performed synchronously or asynchronously.
First, the erase block management table is examined, and an erase block having many actual blocks in a garbage state and having a small erase count is selected. If the erase block contains a busy real block, copy its contents to a free real block of another erase block to make it garbage, make the real block busy, The block conversion table is updated accordingly. When there are no more real blocks in the busy state, the erase block is erased, the erase count is updated, and all the real blocks included in the erase block are set to the free state.

The flash disk management information including the block conversion table and the erase block management table required for such processing is generally stored in a flash ROM.

Conventionally, in a portable information device, when storing information such as the current state of the computer, an address book and documents, a nonvolatile memory, such as a memory, which is stored even when the power is turned off, for example, Store it in flash memory. A memory whose contents are not erased even when the power is turned off often has a very low access speed for reading and writing.

In order to avoid this, the following operation is usually performed. That is, when there is a read request from the non-volatile memory, the data read from the non-volatile memory is stored in a volatile memory, but a RAM with a high access speed. Next, when the same data is read, the data is read from the RAM. When there is a rewrite request for the same data portion, the data read into the RAM is rewritten.

When there is no other work to be processed by the CPU or when there is no free space in the RAM to temporarily store,
The data in the RAM rewritten by the write request is stored in a non-volatile memory having a low access speed. Thus, the RAM is configured to be used as a cache of the nonvolatile memory.

[0008]

However, the above-mentioned information processing apparatus has the following problems, and improvement thereof has been demanded. That is, in a data processing device driven by a battery or a dry battery, such as a portable information terminal, when there is a power supply capacity of the battery or the dry battery, the power is always supplied to the DRAM or the SRAM, and the contents are continuously guaranteed. The system exists. In such a system, the flash disk management information can be arranged in a DRAM or an SRAM. In the case of this method, there is an advantage that rewriting is performed at a higher speed than in the case where the flash ROM is provided.

However, the flash disk management information is
In the case of the method of arranging in a RAM or an SRAM, there is a problem in that if sufficient power is not supplied to the DRAM or the SRAM due to a decrease in power supply capacity such as a battery or a dry cell, important flash disk management information is lost. .

Also, in an information processing apparatus that operates on battery power, when the remaining battery power is low and the battery runs out,
There is a problem that the changed data stored in the volatile RAM is lost.

Therefore, the present invention has been made in view of such a problem, and detects that the power supply capacity has decreased, and when the power supply capacity falls below a predetermined threshold, the flash disk management information arranged on the RAM is stored in the flash ROM. When the system is automatically backed up (written) to a predetermined evacuation area, the power capacity becomes sufficient again by battery charging or battery replacement, and the system is started again, the flash disk management information that has been backed up is stored in RAM. An information processing device that can prevent the flash disk management information from being lost when the power supply capacity is reduced by restoring (copying) the information;
It is an object to provide an information storage method and a storage medium.

Another object of the present invention is to provide an information processing apparatus, an information storage method, and a storage medium that can reduce the amount of data loss even if the battery runs out during writing. And

[0013]

In order to achieve the above object, an information processing apparatus according to claim 1 of the present invention transmits management information necessary for storing data in a nonvolatile memory from a power supply. In an information processing apparatus for storing contents in a volatile memory that retains contents by supplied power, a capacity of the power supply is detected, and it is determined whether or not the detected capacity of the power supply is smaller than a predetermined threshold value. When the power supply capacity detection means determines that the power supply capacity has become smaller than the predetermined threshold value, the information saved in the save area provided in the nonvolatile memory is valid or invalid. The evacuation process determining means for determining that the evacuation process is to be performed if invalid, and the evacuation area when the evacuation process is determined to be performed. To A management information saving unit that writes the management information stored in the volatile memory to perform the saving process and writes that the management information on which the saving process has been performed is valid. It is characterized by having.

According to a second aspect of the present invention, in the information processing apparatus according to the first aspect, upon resetting, it is determined whether the information saved in the save area is valid or invalid. In some cases, it is decided to perform initialization processing,
If it is valid, the return processing determining means for determining that the return processing of the management information is to be performed, and if it is determined that the initialization processing is to be performed, the contents of the nonvolatile memory are erased to initialize the management information. Initialization processing means for performing the return processing, and the return processing means for reading out the management information from the save area and restoring the processing of storing data in the nonvolatile memory when it is determined to perform the return processing. Features.

According to a third aspect of the present invention, in the information processing apparatus according to the first or second aspect, when the management information is updated, the management information saved in the save area becomes invalid. It is characterized by comprising a save information invalidating means for writing that the information has become invalid.

According to a fourth aspect of the present invention, in the information processing apparatus according to the first aspect, the threshold value used for determination by the power supply capacity detecting means cannot retain the contents of the volatile memory. Alternatively, the setting is made according to the capacity of the power supply when the evacuation processing determining means and the management information evacuation means cannot be executed.

According to a fifth aspect of the present invention, in the information processing apparatus according to the first aspect, the threshold value used for determination by the power supply capacity detecting means cannot retain the contents of the volatile memory. Alternatively, the setting is made in accordance with the voltage value of the power supply when the evacuation processing determining means and the management information evacuation means cannot be executed.

According to a sixth aspect of the present invention, in the information processing apparatus according to the first aspect, the management information includes a virtual block when the non-volatile memory is treated as a disk device, and a virtual block having the same size as the virtual block. A block conversion table that maps the non-volatile memory to real blocks that are divided and managed, and a block management table that manages information such as the number of times of erasing of the non-volatile memory, the number of the real blocks, and the state of each real block It is characterized by consisting of.

According to a seventh aspect of the present invention, in the information processing apparatus according to the first aspect, the flag area in which the validity and the invalidity are written includes at least two bits, and the value indicating the validity is: All bits have value 0
, And not all bits are magic numbers having a value of 1, and when switching from the valid to the invalid, all bits are overwritten with a value of 0.

An information storage method according to an eighth aspect of the present invention is an information storage method for storing management information required for storing data in a non-volatile memory in a volatile memory that retains contents by using power supplied from a power supply. Detecting a capacity of the power supply and determining whether the detected capacity of the power supply is less than a predetermined threshold; and determining that the capacity of the power supply is less than the predetermined threshold. When it is determined that the information saved in the save area provided in the nonvolatile memory is valid or invalid, if it is determined that the information is invalid, it is determined that a save process is to be performed and the information is valid. In the case, a step of deciding not to perform the save processing, and, if it is decided to perform the save processing, writing the management information stored in the volatile memory after setting the save area in a writable state Performs saving processing in the management information to which the save process has been performed and having a step of writing to be valid.

According to a ninth aspect of the present invention, in the information storage method according to the eighth aspect, at the time of reset, it is determined whether the information saved in the save area is valid or invalid. In some cases, it is decided to perform initialization processing,
If valid, a step of determining to perform the management information return process, and if it is determined to perform the initialization process,
Erasing the contents of the non-volatile memory to initialize the management information, and, if it is determined to perform the return processing, reading the management information from the save area and storing data in the non-volatile memory And a step of returning the processing.

According to a tenth aspect of the present invention, in the information storage method according to the eighth or ninth aspect, when the management information is updated, the management information saved in the save area becomes invalid. It is characterized by having a step of writing that it has become.

In the information storage method according to an eleventh aspect, in the information storage method according to the eighth aspect, the threshold value used in the step of detecting the capacity of the power supply can hold the content of the volatile memory. It is set in accordance with the capacity of the power supply at the time when it is no longer possible to execute the step of deciding whether or not to perform the save processing and the step of saving the management information.

According to a twelfth aspect of the present invention, in the information storage method according to the eighth aspect, the threshold used in the step of detecting the power supply capacity cannot retain the contents of the volatile memory. Alternatively, the setting is made according to the voltage value of the power supply at the time when the step of determining whether to perform the saving process and the step of saving the management information cannot be performed.

In the information storage method according to the thirteenth aspect, in the information storage method according to the eighth aspect, the management information includes:
A block conversion table that maps a virtual block when the non-volatile memory is treated as a disk device and a real block that is the same size as the virtual block and that divides and manages the non-volatile memory; , A block management table for managing information such as the number of the real block and the state of each real block.

According to a fourteenth aspect of the present invention, in the information storage method according to the eighth aspect, the flag area in which the validity and the invalidity are written includes at least two bits, and the value indicating the validity is: A magic number in which not all bits are 0 and all bits are not 1, and when switching from the valid to the invalid, all bits are overwritten with a value of 0.

A storage medium according to a fifteenth aspect is executed by a CPU in an information processing apparatus, and retains management information required for storing data in a nonvolatile memory by power supplied from a power supply. In a storage medium storing a program to be stored in a volatile memory, the program detects the capacity of the power supply, and determines whether the detected capacity of the power supply is smaller than a predetermined threshold value. And determining whether the information saved in the save area provided in the nonvolatile memory is valid or invalid when it is determined that the capacity of the power supply is smaller than the predetermined threshold. If it is invalid, it is determined that the evacuation process is to be performed. If it is valid, it is determined that the evacuation process is not to be performed. Writing the management information stored in the volatile memory after writing to the volatile memory, and performing a save process, and writing that the management information on which the save process has been performed is valid. Features.

An information processing apparatus according to a sixteenth aspect has a nonvolatile memory and a volatile memory used for storing data, and when storing data in the nonvolatile memory, the volatile memory is temporarily stored in the nonvolatile memory. An information processing device that writes data to the memory and then writes the data to the nonvolatile memory; a power supply capacity detecting unit that detects a capacity of a power supply that supplies power to the volatile memory; In the case of storing, a data storage procedure changing means for changing the data storage procedure based on the detected power supply capacity is provided.

[0029] In the information processing apparatus according to claim 17, in the information processing apparatus according to claim 16, the data storage procedure changing means writes the data into the volatile memory and then writes the data into the nonvolatile memory. Or directly,
It is characterized in that whether to write to the nonvolatile memory is switched.

An information processing apparatus according to claim 18 is the information processing apparatus according to claim 17, wherein when the power supply capacity detecting means detects that the power supply capacity is smaller than a predetermined threshold value, The data is written in the nonvolatile memory.

An information storage method according to a nineteenth aspect has a nonvolatile memory and a volatile memory used for storing data, and when storing data in the nonvolatile memory, the volatile memory is temporarily stored in the nonvolatile memory. In the information storage method for writing data to a memory and then writing the data to the nonvolatile memory, a step of detecting a capacity of a power supply for supplying power to the volatile memory, and a step of storing data in the nonvolatile memory , Based on the detected power supply capacity,
Changing the data storage procedure.

According to a twentieth aspect of the present invention, in the information storage method according to the nineteenth aspect, in the step of changing the data storage procedure, the data is temporarily written into the volatile memory and then stored in the nonvolatile memory. Switching between writing and directly writing to the non-volatile memory is characterized.

According to a twenty-first aspect of the present invention, in the information storage method according to the nineteenth aspect, when the capacity of the power supply is detected to be smaller than a predetermined threshold value in the step of detecting the capacity of the power supply. , Directly in the nonvolatile memory.

The storage medium according to claim 22 is executed by a CPU in an information processing apparatus, and when storing data in a nonvolatile memory, once writes the data to the volatile memory and then stores the data in the nonvolatile memory. In a storage medium storing a program to be written in a nonvolatile memory, the program is configured to detect a capacity of a power supply for supplying power to the volatile memory, and to store data in the nonvolatile memory. And changing the data storage procedure based on the capacity of the power supply.

[0035]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of an information processing apparatus, an information storage method, and a storage medium according to the present invention will be described.

[First Embodiment] FIG. 1 is a block diagram showing a hardware configuration of an information processing apparatus according to a first embodiment. In the figure, reference numeral 1 denotes a battery for supplying power to the apparatus. 2 detects the power supply capacity of the battery 1,
This is a power supply capacity detecting device that interrupts the CPU 3 or changes the register value when the threshold value becomes smaller than the set threshold value.

Reference numeral 3 denotes a CP for executing a program, a driver program, an application program, and the like to be described later.
U. Reference numeral 4 denotes a RAM such as an SRAM or DRAM, and reference numeral 5 denotes a flash (FLASH) ROM. Reference numeral 6 denotes a system bus connecting them. Reference numeral 7 denotes a program code and data (program code / data) such as a program, a driver program, and an application program described later. Reference numeral 8 denotes flash disk management information such as a block conversion table and an erase block management table. The program code / data 7 and the flash disk management information 8 are arranged in the RAM 4.

Reference numeral 9 denotes a flash disk management information save area for saving the flash disk management information 8, and reference numeral 10 denotes a real block area when the flash ROM 5 is used as a disk device. The flash disk management information save area 9 and the real block area 10 are arranged in a flash ROM 5.

Reference numeral 11 denotes a charging connector for connecting an external power supply during charging, and reference numeral 12 denotes a battery charging device that charges the battery 1 based on power from the external power supply connected via the charging connector 11. . Note that the battery 1 may be a dry battery. In this case, since charging is not possible, the charging connector 11 and the battery charger 12 are not required, and a battery replacement operation is required instead of charging.

Reference numeral 13 denotes a liquid crystal display as output means of a user interface of the apparatus, and reference numeral 14 denotes a digitizer as input means. Note that the liquid crystal display 13 and the digitizer 14 may not be provided, and are not particularly limited.

FIG. 2 is a diagram showing two tables constituting the flash disk management information 8. 201 is a block conversion table, and 202 is an erase block management table.

FIG. 3 is a diagram showing the structure of the flash disk management information save area 9 which is an area for saving the block conversion table 201 and the erase block management table 202. Reference numeral 301 denotes a save information valid flag indicating whether the contents of the saved table are valid or invalid.
302 is a block conversion table save area, and 303 is an erase block management table save area. Erase blocks that can store these three areas are allocated as the flash disk management information save area 9.

The save information valid flag 301 requires at least 2 bits, and may be 1 byte or 4 bytes. Then, a value meaning "valid" is determined to a certain magic number in which all bits are not 0 and all bits are not 1. For example, assuming that the save information valid flag 301 is 1 byte, even if 0 (HEX), ff (H
A number other than EX), for example, 12 (HEX) is determined as a magic number. If the save information valid flag 301 is a magic number, it means that the saved information is “valid”, otherwise, it is “invalid”.

That is, assuming that the entire flash disk management information save area 9 has been erased, the save information valid flag 301 becomes ff (HEX), which means that it is "invalid". When switching the flag from “valid” to “invalid”, 0 (HEX) is written.
In this manner, a flash ROM cannot be generally rewritten from a value 0 to a value 1 without erasing it, but can be rewritten from a value 1 to a value 0 without erasing. Can be executed without the erasing process.

Here, a flash ROM
5 generally has the following characteristics. Lead is normal R
Like AM, direct access is possible. Lights can only be erased once. Also, R
The CPU can not write directly like AM,
Flash ROM5 special command string
To be issued to In addition, when overwriting a previously written location, it must be erased once. Also,
Erase can be performed only in units of 64 kbytes (this unit will be referred to as an erase block). And the number of erasures is guaranteed only up to about 100,000.

A flash having such characteristics (Fla)
sh) The driver program generally performs the following processing so that the ROM 5 can be handled like a disk device.

The disk device is handled in block units such as 512 bytes and 1024 bytes. Therefore, as shown in FIG. 4, the real block area 10 of the flash ROM 5 is divided into blocks, and each block is assigned a real block number and managed. FIG. 4 is a diagram showing the real block area 10 of the flash ROM 5.

A block conversion table 201 for converting between a virtual block number and a real block number (FIG. 2A)
Prepare). A file system program or an application program that uses a driver program handles a virtual disk device by specifying a virtual block number.

The erase block management table 20
2 (see FIG. 2B). The erase block management table 202 indicates the erase block state (the number of erases) for each erase block in the real block area 10 and the write state of each real block included in the erase block, that is, free (writable state) / busy ( It manages information indicating whether the state is a state of being written and mapped to a virtual block) or a garbage state (a write-disabled state if not erased).

If the size of the erase block is 64 kbytes and the size of the block is 512 bytes, one erase block contains 128 real blocks. Then, both the erase block and the block are numbered from the value 0.

In the initial state of the driver program, all erase blocks are erased, all real blocks are in a free state, and all the block conversion tables 201 are empty. In the initial state, for example, when a user issues a write request to virtual block number 3 (denoted as virtual block [3]), a target erase block is first selected. In this case, the erase block having the least number of erases is selected. Erase block number 2
(Denoted as erase block [2]) is selected.

Then, the real blocks which are all in the free state are used from the beginning. In this example, the actual block number is 256 (denoted as an actual block [256]). Data is written to the real block [256], and the real block is set to a busy state. Finally, the real block number 256 is written to the entry of the virtual block [3] in the block conversion table 201.

The subsequent write processing that is not overwriting includes the real block [257], the real block [258],. . . And the same processing as above is performed. When the erase block [2] is used up, a new erase block is selected in the same manner as described above, and the same processing is repeated.

When an overwrite write request is issued, for example, when a write request to the virtual block [3] is issued again, first, the real block [256] mapped by the block conversion table 201 is set to a garbage state. Invalidate (erase block management table 20
2 corresponding entries are updated). Then, a new real block is obtained again, data writing processing is performed, the state is changed to a busy state, and the entry of the virtual block [3] in the block conversion table 201 is updated.

As described above, when the overwrite write process is repeated, the number of real blocks in the garbage state increases, and the number of real blocks in the free state decreases. Therefore, it is necessary to perform garbage collection at a certain timing.
When garbage collection is performed, the erase block management table 202 is referred to, and there are no free real blocks, many garbage real blocks, and a small number of erase blocks. All the contents of the busy real block in the erase block are copied to the free real block in another erase block, the copy destination real block is made busy, and the corresponding entry of the corresponding entry in the block conversion table 201 is copied. Updates are also performed.

When all these processes are completed, the erase block is erased (the number of erases in the erase block management table 202 is updated), and all the real blocks belonging to the erase block are set to the free state (the erase block management table 202). 202 is updated). This garbage collection process
It may be performed periodically, or may be performed when the number of actual blocks in the free state falls below a certain threshold.

When a read request is issued, a real block mapped to a designated virtual block is obtained by referring to the block conversion table 201, and its data content is copied to the user's memory area.

By the processing of such a driver program, it is possible to read / write the flash ROM 5 in units of blocks as in a disk device.

The operation of saving and restoring the flash desk management information will be described in detail with reference to the attached flowchart. An appropriate threshold value is set in the power supply capacity detection device 2 in advance. The power supply capacity detection device 2 may detect, for example, a change in voltage value as the power supply capacity. In this case, if the voltage value falls below this, the RAM 4
Is used as a threshold value, which makes it difficult to carry out this processing such as evacuation.
The value is set in the power supply capacity detecting device 2 in advance. The power supply capacity detecting device 2 periodically checks the power supply voltage, and when the power supply voltage becomes lower than the threshold value, interrupts the CPU 3 or changes the register value (readable from the CPU 3).

Also, while the battery 1 has sufficient power to drive the RAM 4, the application program stops temporarily, and even if the CPU 3 shifts to a low power mode such as a sleep mode, the battery 1 keeps the RAM 4 in power. To ensure that its contents are maintained. The RAM 4 is a DRAM, and when it is necessary to switch to a self-refresh mode or the like, a switching process is performed. Thus, when the CPU 3 returns to the normal mode, the execution of the application program can be resumed from where it was once stopped. The flash disk management information 8 can be continuously used as it is.

When the battery 1 runs out of power sufficient to drive the CPU 3 and the RAM 4, the contents of the RAM 4 are destroyed and the battery 1 is not charged via the battery charger 12.
No power is supplied to the CPU 3 and the RAM 4, and the program is not executed. If the battery or one is a dry cell,
Replace the battery instead of charging. When the power is restored, the CPU 3 enters a reset state, and the program starts executing from the reset process.

FIG. 5 is a flowchart showing a processing procedure at the time of reset. This processing program is loaded into the RAM 4 from a storage medium (not shown) and can be executed by the CPU 3. First, it is checked whether the save information valid flag 301 is a magic number (step S501), and it is determined whether the saved information is "valid" or "invalid" (step S502). If it is determined to be "invalid", an initialization process after step S503 is performed.

In the processing at the time of resetting, it is determined that the apparatus is "invalid" when the apparatus is in a complete initial state and the flash ROM 5 is completely erased or in an indefinite state. This means that the save information valid flag 301 has a value different from the magic number.

In this case, an initialization process is performed. All the erase blocks in the flash ROM 5 are erased (step S503). All the real block numbers in the block conversion table 201 are emptied (step S504). The number of all erases in the erase block management table 202 is initialized to 1 (step S505). All the real block states in the erase block management table 202 are set to the free state (step S506), and the process ends.

On the other hand, if it is determined in step S502 that the flash disk management information is "valid", processing for restoring the saved flash disk management information is performed. The contents of the block conversion table save area 302 are copied to the block conversion table 201 and the process returns (step S510). The contents of the erase block management table save area 303 are copied to the erase block management table 202 and the process is restored (step S511), and the process is terminated.

FIG. 6 is a flowchart showing an evacuation procedure when the power supply capacity detecting device 2 detects that the voltage value of the battery 1 has fallen below a preset threshold value. This processing program can be loaded into the RAM 4 from a storage medium (not shown) and executed by the CPU 3 as in FIG. In the present embodiment, the power supply capacity detecting device 2
The method of interrupting the CPU 3 when detecting that the voltage value has dropped below the threshold value will be described.
In the case of changing the register value, a program operating on the CPU 3 may periodically read the register and, if the value has changed, start the process from step S602 in FIG.

First, when an interrupt is raised from the power supply capacity detecting device 2 to the CPU 3 (step S601), the following interrupt processing program (task or the like) corresponding to this interrupt or another processing program started by the interrupt processing program causes the following. Execute the process.

It is checked whether the save information valid flag 301 is a magic number (step S602), and it is determined whether the saved information is "valid" or "invalid" (step S602).
603). In the case of “valid”, there is no need to perform the save processing, and the subsequent processing ends. On the other hand, in the case of “invalid”, the evacuation processing is performed, and the process proceeds to the processing after step S604.

All the erase blocks in the flash disk management information save area 9 are erased to enable writing of information (step S604). Block conversion table 20
1 is written to the block conversion table save area 302 and saved (step S605). The contents of the erase block management table 202 are written and saved in the erase block management table save area 303 (step S606). The magic number is written in the save information valid flag 301, indicating that the saved information is "valid" (step S607). Then, the process ends.

Next, the read, write, and garbage collection processes will be described. These processes are basically the same as the above-described general read, write, and garbage collection processes. However, the block conversion table 20
1. During write processing and garbage collection processing involving updating of the erase block management table 202, the value 0 is set in the save information valid flag 301 to indicate that the information in the flash disk management information save area 9 has become “invalid”.
Write the value (all bits are value 0). Flash R
In the OM, writing of the value 0 is generally possible without performing the erase process. In other words, the change from the magic number to the value 0 does not require the erasing process, and writing the value 0 is sufficient.

As described above, in the present embodiment, even if the flash disk management information 8 is arranged in the RAM 4, the capacity of the battery or the dry battery is reduced, and the contents of the flash disk management information may be destroyed. Then, if necessary, the contents are automatically written into a predetermined save area of the flash ROM and saved.

When the power is restored again by charging or battery replacement and the reset process is started, the saved flash disk management information is read out to a predetermined area of the RAM 4 and returned. For this reason, even if the flash disk management information is arranged in a high-speed readable / writable RAM, an information processing apparatus having a pseudo disk device using a flash ROM that does not lose its contents due to power reduction is provided. be able to.

[Second Embodiment] The information processing apparatus according to the second embodiment is applied to a portable information device. 7 and 8 are block diagrams showing the configuration and operation of the portable information device according to the second embodiment. In the figure, 1
Reference numeral 01 denotes a battery remaining amount detection device that detects that the voltage of the battery 102 has dropped.

Reference numeral 102 denotes a battery for supplying a power supply voltage to the portable information device. Reference numeral 103 denotes a non-volatile RAM such as a flash ROM which stores data even when no power supply voltage is supplied but has a lower access speed than a volatile memory. 104 is a CPU. 106 is a CPU
A ROM that stores programs and data for operating the RAM 104. Reference numeral 107 denotes a RAM in which the CPU 104 stores temporary data.

Reference numeral 109 denotes a display (display device). Reference numeral 108 denotes a display driving device for driving the display device 108. A communication device 105 communicates with an external device. Reference numeral 110 denotes an input device (coordinate input device) for inputting data to the computer.

Reference numeral 111 denotes a bus for exchanging data with the ROM 106, the RAM 107, and the display driving device 108. Reference numeral 112 denotes an I / O bus for exchanging data with the communication device 105. Part of the RAM 107 is allocated to a temporary storage area of the nonvolatile RAM 103.

FIG. 9 is a diagram showing a management structure for managing a temporary storage area of the nonvolatile RAM 103 allocated to the RAM 107. In the figure, 401 is a table for managing data to be written, and 402 is data to be written in the nonvolatile RAM 103.

FIG. 10 is a diagram showing the appearance of a portable information device as a computer which operates on battery power. In the figure, reference numeral 701 denotes a CPU 104, a ROM 106, a RAM 1
07, the nonvolatile RAM 103, the display driving device 1
08, a main body for housing the input device 110 and the like.

In the example shown in FIG. 7, the input device 110 is constituted by a digitizer that can be input with a pen, and the digitizer is superimposed on the display 109. Reference numeral 702 denotes a pen for inputting data to a computer, and reference numeral 703 denotes a wireless telephone terminal for performing data communication.

In the portable information device having such a configuration, a case where data is written to the nonvolatile RAM 103 when registering an address of an address book input by a user will be described. FIG. 11 is a flowchart showing a data write processing procedure when writing data to the nonvolatile RAM 103. This processing program, as described above,
It is stored in M106 and executed by the CPU 104.

First, it is checked whether the area allocated to the RAM 107 as a temporary storage area of the nonvolatile RAM 103 is full (step S701). RAM
If the area allocated to 107 is full, an operation (flash operation) of writing to the nonvolatile RAM 103 is performed (step S702). Then, the process ends.

On the other hand, if the area allocated to the RAM 107 is not full, the remaining battery level is checked using the battery voltage detecting device 101 (step S703). If the remaining battery level is low, the non-volatile RAM 103 allocated to the RAM 107 is used. Is written directly to the nonvolatile RAM 103 without using the temporary storage area (see arrow c in FIG. 8, step S704). Then, the process ends.

On the other hand, if the battery capacity is sufficient, the flow shifts to step S705 to perform normal write processing (steps S705 to S707). In normal write processing, a table 401 for managing data to be written is allocated (step S705). In this table, an “unwritten” flag indicating that writing to the non-volatile RAM 103 has not yet been set is set (step S706). This table is written in a free area in the temporary storage area of the nonvolatile RAM 103 allocated to the RAM 107, and a link is made to the data written by this table (step S707). Then, the process ends.

In such a portable information device, a case where a user reads data such as an address in an address book will be described. FIG. 12 is a flowchart showing the data read processing procedure. This processing program is stored in the ROM 106 like the data writing processing program, and is executed by the CPU 104. First, it is determined whether or not the data requested by the user is in a temporary storage area of the nonvolatile RAM 103 allocated to the RAM 107 (step S801). This can be determined by checking while following the link of the table 401 in FIG.

When data to be read is in the RAM 107, the data is read from the RAM 107 (see arrow a in FIG. 7).
Step S802). On the other hand, if the data to be read is RA
If it is not in M107, it is read from the nonvolatile RAM 103 (see arrow c in FIG. 8, step S803). And
The process ends.

FIG. 13 is a flowchart showing a processing procedure of a write (flash) operation to the nonvolatile RAM 103 in step S702 of FIG. First, the first table 401 is extracted (step S901). It is checked whether or not an “unwritten” flag is set in the table (step S902). If the unwritten flag is set, the data 402 linked to the table 401 is written in the nonvolatile RAM 103 (step S903), and the unwritten flag attached to the table 401 is lowered (see arrow b in FIG. 7). , Step S9
04).

If the "unwritten" flag is not set in the table in step S902, or
When the unwritten flag attached to the table 401 is cleared in 904, the next linked table is checked (step S905). If there is a next linked table, the process returns to step S902,
If there is no next linked table, the process ends.

By continuing this work, the nonvolatile RAM
Data that has not been written to 103 can be written. That is, the CPU 104 normally writes data to be stored in the nonvolatile memory 103 in the order of arrows a and b in FIG. 7. However, when the battery capacity is low, the CPU 104 directly writes data as shown by an arrow c in FIG. Write.

As described above, in the present embodiment, writing of data to the portable information device by the user is apparently faster, and when the battery capacity of the portable information device is small, the battery runs out during writing. Even in this case, when the battery is low, the data is written directly to the nonvolatile RAM 103, so that the data loss can be minimized.

The present invention may be applied to a system composed of a plurality of devices, or may be applied to an apparatus composed of one device. Needless to say, the present invention can be applied to a case where the present invention is achieved by supplying a program to a system or an apparatus. In this case, by reading out a storage medium storing a program represented by software for achieving the present invention into a system or an apparatus, the system or the apparatus can enjoy the effects of the present invention.

FIG. 14 is a diagram showing a memory map of a storage medium such as a ROM. The storage medium shown in FIG.
The reset processing module of FIG. 5 and the evacuation processing module at the time of battery voltage drop of FIG. 6 are stored. The ROM 106 shown in FIG. 14B stores the data write processing module of FIG. 11, the data read processing module of FIG. 12, the flash operation processing module of FIG. 13, and the like.

The storage medium is not limited to ROM, but may be a floppy disk, hard disk, optical disk,
A magneto-optical disk, a CD-ROM, a CD-R, a DVD, a magnetic tape, a nonvolatile memory card, or the like can be used.

After the program code read from the storage medium is written in the memory provided in the function expansion board inserted into the computer or the function expansion unit connected to the computer, the program code is read based on the instruction of the program code. The CPU provided in the function expansion board or function expansion unit performs part or all of the actual processing,
It goes without saying that the processing may realize the functions of the above-described embodiments.

[0094]

According to the information processing apparatus according to the first aspect of the present invention, the management information necessary for storing data in the nonvolatile memory is stored in the volatile memory which retains the contents by the power supplied from the power supply. When storing in the volatile memory, the power supply capacity detecting means detects the capacity of the power supply, and determines whether or not the detected power supply capacity is smaller than a predetermined threshold value. Is determined to be less than the threshold value, the save processing determining means checks whether the information saved in the save area provided in the nonvolatile memory is valid or invalid. If it is determined that the save process is to be performed, if it is valid, it is determined that the save process is not to be performed, and if it is determined that the save process is to be performed, the management information saving unit may set the save area to a writable state. The evacuation process is performed by writing the management information stored in the volatile memory, and the fact that the management information subjected to the evacuation process is valid is written. If the threshold value is less than the threshold value, the flash disk management information arranged in the RAM is automatically saved (written) to a predetermined save area in the flash ROM, and the power supply capacity becomes sufficient again by charging the battery or replacing the battery. By restoring (copying) the saved flash disk management information to the RAM when is restarted, it is possible to prevent the flash disk management information from being lost when the power supply capacity is reduced.

As described above, when the power capacity of the battery or the dry battery is reduced and the contents of the RAM cannot be maintained, the power capacity detection means detects the power capacity and the information saved in the predetermined save area in the flash ROM. If it is "invalid", the management information saving means saves the flash disk management information such as the block conversion table and the erase block management table to a predetermined area in the flash ROM, and the saved information becomes "valid".
Is written.

Therefore, even if the flash disk management information is stored in the RAM, if the capacity of the battery or the dry battery becomes small and the contents of the flash disk management information may be destroyed, if necessary, The contents are automatically written and saved in a predetermined save area on the flash ROM. Then, when the power is restored again by the charging or the battery replacement and the reset process is started, the saved flash disk management information is read out to a predetermined area on the RAM and returned. For this reason, even if the flash disk management information is arranged on a RAM that can be read / written at high speed, the effect of preventing the contents from being destroyed due to power reduction can be obtained. Claim 8
The same effect can be obtained also in the information storage method described in (1) and the storage medium described in (15).

According to the information processing apparatus of the second aspect,
At the time of reset by the return processing determining means, it is checked whether the information saved in the save area is valid or invalid,
If invalid, it is determined that initialization processing is to be performed.If valid, it is determined that recovery processing of the management information is to be performed. If it is determined that the initialization processing is to be performed, the non-volatile A process of erasing the management information by erasing the contents of the non-volatile memory and reading the management information from the save area by a restoration processing unit when it is determined that the restoration process is to be performed, and storing the data in the nonvolatile memory , The flash disk information can be reliably managed at the time of reset.

Thus, when the system is reset,
The return processing determining means determines whether the information saved in a predetermined save area in the flash ROM is “invalid” or “valid”. If the information is “invalid”, the initialization processing means initializes the disk device. When the “valid” status is obtained, the flash disk management information such as the block conversion table and the erase block management table is restored from the predetermined save area by the management information restoration unit. The same effect can be obtained in the information storage method according to the ninth aspect.

According to the information processing apparatus of the third aspect,
When the management information is updated, the fact that the management information saved in the save area is invalidated by the save information invalidating means is written, so that the management information saved in the save area is appropriately managed. Can be.

As described above, when the flash disk management information such as the block conversion table and the erase block management table is updated by the write processing or the garbage collection processing as the disk device, the evacuation information invalidating means causes the predetermined information in the flash ROM to be updated. The information saved in the save area is marked as “invalid”. The same effect can be obtained in the information storage method according to the tenth aspect.

According to the information processing apparatus of the fourth aspect,
The threshold value used for the determination by the power supply capacity detection means is determined by the capacity of the power supply when the contents of the volatile memory cannot be held or the save processing determination means and the management information save means cannot be executed. Since the management information is set accordingly, the management information can be reliably saved before the management information stored in the volatile memory is lost. Note that the same effect can be obtained in the information processing apparatus according to the fifth aspect and the information storage method according to the eleventh and twelfth aspects.

According to the information processing apparatus of claim 6,
The management information includes a block conversion table that maps a virtual block when the non-volatile memory is treated as a disk device, and a real block that is the same size as the virtual block and that divides and manages the non-volatile memory. Since the block management table manages information such as the number of times of erasure of the memory, the number of the real block, and the state of each real block, the block conversion table and the block management table can be reliably managed. In the information storage method according to the thirteenth aspect,
Similar effects can be obtained.

According to the information processing apparatus of claim 7,
The flag area in which the validity and the invalidity are written,
It is composed of at least 2 bits, and the value indicating the validity is:
A magic number in which all bits are not 0 and all bits are not 1 and when switching from the valid to the invalid, all bits are overwritten with the value 0. The distinction can be made surely, and when a flash ROM is used, the switching from valid to invalid can be performed by overwriting without performing erasing. The same effect can be obtained in the information storage method according to the fourteenth aspect.

According to the storage medium of the fifteenth aspect, the management information executed by the CPU in the information processing apparatus and required for storing data in the non-volatile memory is stored by the power supplied from the power supply. In a storage medium storing a program for storing in a volatile memory holding
A step of detecting the capacity of the power supply and determining whether the detected capacity of the power supply is smaller than a predetermined threshold; and a step of determining whether the capacity of the power supply is smaller than the predetermined threshold. If it is determined that the information has become invalid, it is determined whether the information saved in the save area provided in the nonvolatile memory is valid or invalid. In some cases, a procedure for deciding not to perform the save processing, and a procedure for deciding to perform the save processing, by writing the management information stored in the volatile memory after setting the save area in a writable state. A procedure for performing the saving process and writing that the management information for which the saving process has been performed is valid is included, so that the expandability and versatility of the information processing apparatus can be improved. still,
The same effect can be obtained also in the storage medium according to the present invention.

According to the information processing apparatus of the present invention, there is provided a nonvolatile memory and a volatile memory used for storing data, and when storing data in the nonvolatile memory, Once the data is written to the volatile memory, when the data is written to the non-volatile memory, the power supply capacity detecting means detects the capacity of a power supply for supplying power to the volatile memory, and stores the data in the non-volatile memory. When storing data, the data storage procedure is changed based on the detected power supply capacity by the data storage procedure changing means. Therefore, even if the battery runs out during writing, the amount of data loss can be reduced. Can be reduced. The same effect can be obtained with the information storage method according to the nineteenth aspect and the storage medium according to the twenty-second aspect.

According to the information processing apparatus of the present invention, the data storage procedure changing means writes the data to the volatile memory and then writes it to the nonvolatile memory, or directly writes the data to the nonvolatile memory. Since writing or writing is switched, a writing procedure to a nonvolatile memory such as a flash ROM can be changed. It should be noted that the same effect can be obtained in the information storage method according to the twentieth aspect.

According to the information processing apparatus of the present invention, when the power supply capacity detection means detects that the capacity of the power supply is smaller than a predetermined threshold value, the power is directly written to the nonvolatile memory. Before the data stored in the volatile memory is lost, the data can be written to the nonvolatile memory. It should be noted that a similar effect can be obtained in the information storage method according to the twenty-first aspect.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a hardware configuration of an information processing apparatus according to a first embodiment.

FIG. 2 is a diagram showing two tables constituting flash disk management information 8;

FIG. 3 is a diagram showing a configuration of a flash disk management information save area 9 which is an area for saving a block conversion table 201 and an erase block management table 202.

FIG. 4 is a diagram showing a real block area 10 of the flash ROM 5;

FIG. 5 is a flowchart showing a processing procedure at the time of reset.

FIG. 6 is a flowchart illustrating an evacuation processing procedure when the power supply capacity detecting device 2 detects that the voltage value of the battery 1 has dropped below a preset threshold value.

FIG. 7 is a block diagram illustrating the configuration and operation of a portable information device according to a second embodiment.

FIG. 8 is a block diagram illustrating a configuration and an operation of the portable information device.

FIG. 9 is a non-volatile RAM assigned to a RAM 107;
FIG. 3 is a diagram showing a management structure for managing a temporary storage area of a storage area 103;

FIG. 10 is a diagram illustrating an appearance of a portable information device as a computer that operates on battery power.

FIG. 11 is a flowchart illustrating a data write processing procedure when data is written to the nonvolatile RAM 103;

FIG. 12 is a flowchart illustrating a data read processing procedure;

FIG. 13 is a flowchart showing a processing procedure of a write (flash) operation to the nonvolatile RAM 103 in step S702 of FIG. 11;

FIG. 14 is a diagram showing a memory map of a storage medium such as a ROM.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 102 Battery 2 Power supply capacity detection apparatus 3, 104 CPU 4 RAM 5 Flash (Flash) ROM 8 Flash disk management information 9 Flash disk management information save area 10 Real block area 101 Battery voltage detection apparatus 103 Non-volatile RAM 106 ROM 107 RAM 201 Block conversion table 202 Erase block management table 301 Save information valid flag

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5B011 DA06 DA13 EA04 EB01 GG03 JA04 5B018 GA04 HA23 KA03 LA03 MA23 NA06 QA05 QA11 5B019 CA05 HF03 5B098 DD02 DD08

Claims (22)

[Claims] 1. An information processing apparatus for storing management information necessary for storing data in a nonvolatile memory in a volatile memory that retains contents by power supplied from a power supply, wherein the capacity of the power supply is detected. And a power supply capacity detecting means for determining whether or not the detected capacity of the power supply has become smaller than a predetermined threshold value, and when it is determined that the capacity of the power supply has become smaller than the predetermined threshold value, Check whether the information saved in the save area provided in the non-volatile memory is valid or invalid, and if invalid, decide to perform the save process,
A save processing determining means for determining not to perform the save processing when the save processing is valid; and a management stored in the volatile memory after setting the save area to a writable state when the save processing is determined to be performed. An information processing apparatus comprising: a management information saving unit that performs saving processing by writing information and that writes that the management information on which the saving processing has been performed is valid. 2. When resetting, it is determined whether the information saved in the save area is valid or invalid. If the information is invalid, it is determined that an initialization process is to be performed.
Return processing determining means for determining to perform the management information return processing; and initialization processing means for initializing the management information by erasing the contents of the non-volatile memory when the initialization processing is determined to be performed. And return processing means for reading out the management information from the save area when it is determined to perform the return processing and returning the processing of storing data in the nonvolatile memory. The information processing apparatus according to claim 1. 3. The information processing apparatus according to claim 1, further comprising: a save information invalidating unit that writes that the management information saved in the save area is invalid when the management information is updated. Item 3. The information processing device according to Item 2. 4. A threshold value used for determination by the power supply capacity detecting means when the contents of the volatile memory cannot be held or when the saving processing determining means and the management information saving means cannot be executed. 2. The information processing apparatus according to claim 1, wherein the information processing apparatus is set according to a capacity of the power supply. 5. A threshold value used for determination by said power supply capacity detecting means when the contents of said volatile memory cannot be held or when said saving processing determining means and said management information saving means cannot be executed. 2. The power supply according to claim 1, wherein the power supply is set according to a voltage value of the power supply.
An information processing apparatus according to claim 1. 6. The management information is a block conversion that maps a virtual block when the non-volatile memory is treated as a disk device and a real block that is the same size as the virtual block and that divides and manages the non-volatile memory. 2. The information processing apparatus according to claim 1, comprising a table and a block management table for managing information such as the number of times of erasing of the nonvolatile memory, the number of the real block, and the state of each real block. 7. The flag area in which the validity and the invalidity are written is composed of at least two bits, and the value indicating the validity is a magic number in which all bits are not 0 and not all bits are 1. The information processing apparatus according to claim 1, wherein when switching from the valid state to the invalid state, all bits are overwritten with a value of 0. 8. An information storage method for storing management information required for storing data in a non-volatile memory in a volatile memory which retains contents by power supplied from a power supply, wherein the capacity of the power supply is detected. Determining whether the detected power supply capacity is less than a predetermined threshold value; and determining that the power supply capacity is less than the predetermined threshold value. Check whether the information saved in the save area provided in the memory is valid or invalid, and if invalid, decide to perform the save process,
If valid, a step of deciding not to perform the save processing; and, if it is decided to perform the save processing, write the management information stored in the volatile memory after setting the save area in a writable state. Performing an evacuation process and writing that the management information subjected to the evacuation process is valid. 9. When resetting, it is determined whether the information saved in the save area is valid or invalid. If the information is invalid, it is determined that an initialization process is to be performed.
A step of deciding to perform a return process of the management information; and a step of erasing the contents of the non-volatile memory to initialize the management information when it is decided to perform the initialization process. 9. The information storage method according to claim 8, further comprising a step of reading the management information from the evacuation area and restoring a process of storing data in the non-volatile memory when it is determined to be performed. 10. The information according to claim 8, further comprising a step of writing that the management information saved in the save area becomes invalid when the management information is updated. Storage method. 11. The threshold value used in the step of detecting the capacity of the power supply, the step of determining whether or not the content of the volatile memory cannot be held, or the step of determining whether to perform the save processing, and the management information 9. The information storage method according to claim 8, wherein the information is set according to the capacity of the power supply when the step of saving the data cannot be executed. 12. The threshold value used in the step of detecting the power supply capacity includes a step of determining whether or not the content of the volatile memory cannot be held or a step of determining whether or not to perform the save processing, and 9. The information storage method according to claim 8, wherein the information is set in accordance with a voltage value of the power supply when the step of saving cannot be performed. 13. The management information is a block conversion that maps a virtual block when the non-volatile memory is treated as a disk device and a real block that is the same size as the virtual block and is divided and managed in the non-volatile memory. 9. The information storage method according to claim 8, comprising a table and a block management table for managing information such as the number of times of erasing of the nonvolatile memory, the number of the real block, and the state of each real block. 14. The flag area in which the validity and the invalidity are written is composed of at least two bits, and the value indicating the validity is a magic number in which all bits are not 0 and not all bits are 1. The information storage method according to claim 8, wherein when switching from the valid to the invalid, all bits are overwritten with a value of 0. 15. A program that is executed by a CPU in an information processing apparatus and stores management information necessary for storing data in a nonvolatile memory in a volatile memory that retains contents by power supplied from a power supply. In the storage medium, the program detects a capacity of the power supply, and determines whether or not the detected capacity of the power supply is smaller than a predetermined threshold value. When it is determined that the information has become smaller than the predetermined threshold value, it is checked whether the information saved in the save area provided in the nonvolatile memory is valid or invalid. Decided to do
If the evacuation process is determined to be not performed, and if the evacuation process is determined to be performed, the management area stored in the volatile memory is written after the evacuation area is in a writable state. And a procedure for performing a save process and writing that the management information on which the save process has been performed is valid. 16. A nonvolatile memory having a nonvolatile memory and a volatile memory used for storing data. When storing data in the nonvolatile memory, the data is temporarily written to the volatile memory, An information processing device that writes data to the nonvolatile memory; a power supply capacity detecting unit that detects a capacity of a power supply that supplies power to the volatile memory; and a power supply that stores the data in the nonvolatile memory. And a data storage procedure changing means for changing the data storage procedure based on the capacity of the information processing apparatus. 17. The data storage procedure changing unit switches between writing once in the volatile memory and then writing in the nonvolatile memory or directly writing in the nonvolatile memory. 16
An information processing apparatus according to claim 1. 18. When the power supply capacity detection means detects that the capacity of the power supply is smaller than a predetermined threshold value,
18. The information processing apparatus according to claim 17, wherein the information is directly written to the nonvolatile memory. 19. A nonvolatile memory and a volatile memory which are used when storing data. When storing data in the nonvolatile memory, the data is written to the volatile memory once, In an information storage method for writing data to the nonvolatile memory, a step of detecting a capacity of a power supply for supplying power to the volatile memory; and when storing data in the nonvolatile memory, the detected capacity of the power supply is Changing the data storage procedure based on the information storage method. 20. In the step of changing the data storage procedure, switching is performed between writing to the volatile memory and then writing to the nonvolatile memory or directly writing to the nonvolatile memory. 20. The information storage method according to claim 19, wherein: 21. The non-volatile memory according to claim 19, wherein in the step of detecting the capacity of the power supply, when it is detected that the capacity of the power supply is smaller than a predetermined threshold value, the data is directly written to the nonvolatile memory. Information storage method. 22. Executed by the CPU in the information processing apparatus, and when storing data in the nonvolatile memory,
After writing data to the volatile memory, in a storage medium storing a program for writing the data to the non-volatile memory, the program comprises: a step of detecting a capacity of a power supply for supplying power to the volatile memory; Storing data in the non-volatile memory, the method including changing a data storage procedure based on the detected power supply capacity.