Selecting erase method based on type of power supply for flash eeprom

A computer control apparatus for controlling a computer by reading out a predetermined program from a memory medium, wherein

• said memory medium stores a control program which forms a plurality of data areas and management areas corresponding to the data areas in a flash ROM and controls data storage of said flash ROM, and
• the control program comprises:
• a procedure code of the writing step of receiving a write instruction containing specification information which specifies a data write destination, writing data in one of the data areas, and writing the specification information in a management area corresponding to the data area;
• and
• a procedure code of the reading step of receiving a read instruction containing specification information which specifies a data read source, retrieval-accessing a management area in which the specification information is stored, and reading out data stored in a data region corresponding to the retrieval-accessed management area.

A flash ROM management apparatus comprising:

• managing means for forming a plurality of storage blocks each consisting of a data area and a management area corresponding to the data area in a flash ROM, storing state information indicating a storage state of the data area of each storage block in the management area of the storage block, and managing access to said flash ROM on the basis of the state information;
• first erasing means for extracting, from one erase block of said flash ROM, on the basis of the state information, a storage block in which valid data exists in the data area, moving contents of the extracted storage block, and erasing the erase block;
• second erasing means for extracting, from a plurality of erase blocks, on the basis of the state information, storage blocks in which valid data exists in the data area, moving contents of the extracted storage blocks to a storage area including a random access memory, and erasing the erase blocks;
• and
• executing means for selecting one of said first erasing means and said second erasing means and executing the erase operation on the basis of the type of power supply of an apparatus into which said flash ROM is incorporated.

A flash ROM management method comprising:

• the managing step of forming a plurality of storage blocks each consisting of a data area and a management area corresponding to the data area in a flash ROM, storing state information indicating a storage state of the data area of each storage block in the management area of the storage block, and managing access to said flash ROM on the basis of the state information;
• the first erasing step of extracting, from one erase block of said flash ROM, on the basis of the state information, a storage block in which valid data exists in the data area, moving contents of the extracted storage block, and erasing the erase block;
• the second erasing step of extracting, from a plurality of erase blocks, on the basis of the state information, storage blocks in which valid data exists in the data area, moving contents of the extracted storage blocks to a storage area including a random access memory, and erasing the erase blocks;
• and
• the executing step of selecting one of said first erasing step and said second erasing step and executing the erase operation on the basis of the type of power supply of an apparatus into which said flash ROM is incorporated.

A computer control apparatus for controlling a computer by reading out a predetermined program from a memory medium, wherein said memory medium comprises:

• a procedure code of the managing step of forming a plurality of storage blocks each consisting of a data area and a management area corresponding to the data area in a flash ROM, storing state information indicating a storage state of the data area of each storage block in the management area of the storage block, and managing access to said flash ROM on the basis of the state information;
• a procedure code of the first erasing step of extracting, from one erase block of said flash ROM, on the basis of the state information, a storage block in which valid data exists in the data area, moving contents of the extracted storage block, and erasing the erase block;
• a procedure code of the second erasing step of extracting, from a plurality of erase blocks, on the basis of the state information, storage blocks in which valid data exists in the data area, moving contents of the extracted storage blocks to a storage area including a random access memory, and erasing the erase blocks;
• and
• a procedure code of the executing step of selecting one of said first erasing step and said second erasing step and executing the erase operation on the basis of the type of power supply of an apparatus into which said flash ROM is incorporated.

A flash ROM management apparatus comprising:

• managing means for forming a plurality of storage blocks each consisting of a data area and a management area corresponding to the data area in a flash ROM, storing state information indicating a storage state of the data area of each storage block in the management area of the storage block, and managing access to said flash ROM on the basis of the state information;
• erasing means for extracting, from an erase block of said flash ROM, on the basis of the state information, a storage block in which valid data exists in the data area, moving contents of the extracted storage block, and erasing the erase block;
• count means for counting the number of erase operations performed by said erasing means as an erase count and storing the erase count in a storage area of an erase block;
• and
• determining means for determining an erase block to be erased by said erasing means on the basis of the erase count.

A flash ROM management method comprising:

• the managing step of forming a plurality of storage blocks each consisting of a data area and a management area corresponding to the data area in a flash ROM, storing state information indicating a storage state of the data area of each storage block in the management area of the storage block, and managing access to said flash ROM on the basis of the state information;
• the erasing step of extracting, from an erase block of said flash ROM, on the basis of the state information, a storage block in which valid data exists in the data area, moving contents of the extracted storage block, and erasing the erase block;
• the count step of counting the number of erase operations performed by the erasing step as an erase count and storing the erase count in a storage area of an erase block;
• and
• the determining step of determining an erase block to be erased by the erasing step on the basis of the erase count.

A computer control apparatus for controlling a computer by reading out a predetermined program from a memory medium, wherein said memory medium comprises:

• a procedure code of the managing step of forming a plurality of storage blocks each consisting of a data area and a management area corresponding to the data area in a flash ROM, storing state information indicating a storage state of the data area of each storage block in the management area of the storage block, and managing access to said flash ROM on the basis of the state information;
• a procedure code of the erasing step of extracting, from an erase block of said flash ROM, on the basis of the state information, a storage block in which valid data exists in the data area, moving contents of the extracted storage block, and erasing the erase block;
• a procedure code of the count step of counting the number of erase operations performed by the erasing step as an erase count and storing the erase count in a storage area of an erase block;
• and
• a procedure code of the determining step of determining an erase block to be erased by the erasing step on the basis of the erase count.

A flash ROM management apparatus in a system capable of executing a plurality of tasks in parallel in accordance with priorities of the tasks, comprising:

• managing means for forming a plurality of storage blocks each consisting of a data area and a management area corresponding to the data area in a flash ROM, storing state information indicating a storage state of the data area of each storage block in the management area of the storage block, and managing access to said flash ROM on the basis of the state information;
• preprocessing means for performing preprocessing of improving an erase speed for a storage block whose state information indicates invalid data;
• and
• executing means for executing said preprocessing means by assigning the execution to a task having a low priority of the plurality of tasks.

A flash ROM management method in a system capable of executing a plurality of tasks in parallel in accordance with priorities of the tasks, comprising:

• the managing step of forming a plurality of storage blocks each consisting of a data area and a management area corresponding to the data area in a flash ROM, storing state information indicating a storage state of the data area of each storage block in the management area of the storage block, and managing access to said flash ROM on the basis of the state information;
• the preprocessing step of performing preprocessing of improving an erase speed-for a storage block whose state information indicates invalid data;
• and
• the executing step of executing the preprocessing step by assigning the execution to a task having a low priority of the plurality of tasks.

A computer control apparatus for controlling a computer by reading out a predetermined program from a memory medium, wherein said memory medium comprises:

• a procedure code of the managing step of forming a plurality of storage blocks each consisting of a data area and a management area corresponding to the data area in a flash ROM, storing state information indicating a storage state of the data area of each storage block in the management area of the storage block, and managing access to said flash ROM on the basis of the state information;
• a procedure code of the preprocessing step of performing preprocessing of improving an erase speed for a storage block whose state information indicates invalid data;
• and
• a procedure code of the executing step of executing the preprocessing step by assigning the execution to a task having a low priority of a plurality of tasks whose executions are scheduled in accordance with given priorities.

A flash ROM management apparatus comprising:

• managing means for forming a plurality of storage blocks each consisting of a data area and a management area corresponding to the data area in a flash ROM, storing state information indicating a storage state of the data area of each storage block in the management area-of the storage block, and managing access to said flash ROM on the basis of the state information;
• first determining means for determining whether the storage block contains predetermined information to be buffered by using a cache;
• and
• buffer means for performing buffering for caching in units of storage blocks for the storage blocks determined by said first determining means to require buffering.

A flash ROM management method comprising:

• the managing step of forming a plurality of storage blocks each consisting of a data area and a management area corresponding to the data area in a flash ROM, storing state information indicating a storage state of the data area of each storage block in the management area of the storage block, and managing access to said flash ROM on the basis of the state information;
• the first determining step of determining whether the storage block contains predetermined information to be buffered by using a cache;
• and
• the buffer step of performing buffering for caching in units of storage blocks for the storage blocks determined in the first determining step to require buffering.

A computer control apparatus for controlling a computer by reading out a predetermined program from a memory medium, wherein said memory medium comprises:

• a procedure code of the managing step of forming a plurality of storage blocks each consisting of a data area and a management area corresponding to the data area in a flash ROM, storing state information indicating a storage state of the data area of each storage block in the management area of the storage block, and managing access to said flash ROM on the basis of the state information;
• a procedure code of the first determining step of determining whether the storage block contains predetermined information to be buffered by using a cache;
• and
• a procedure code of the buffer step of performing buffering for caching in units of storage blocks for the storage blocks determined in the first determining step to require buffering.

A flash ROM management apparatus comprising:

• managing means for forming a plurality of storage blocks each consisting of a data area and a management area corresponding to the data area in a flash ROM, storing state information indicating a storage state of the data area of each storage block in the management area of the storage block, and managing access to said flash ROM on the basis of the state information;
• saving means for extracting, from an erase block of said flash ROM, by referring to the state information in the management area, a storage block in which data in the data area is valid, and saving contents of the extracted storage block to the outside of the erase block;
• erasing means for erasing the erase block after said saving means has saved all storage blocks containing valid data in the erase block;
• and
• extra storage blocks in addition to the storage blocks to be accessed by said managing means.

A flash ROM management method comprising:

• the managing step of forming a plurality of storage blocks each consisting of a data area and a management area corresponding to the data area in a flash ROM, storing state information indicating a storage state of the data area of each storage block in the management area of the storage block, and managing access to said flash ROM on the basis of the state information;
• the saving step of extracting, from an erase block of said flash ROM, by referring to the state information in the management area, a storage block in which data in the data area is valid, and saving contents of the extracted storage block to the outside of the erase block;
• and
• the erasing step of erasing the erase block after the saving step has saved all storage blocks containing valid data in the erase block,
• wherein the managing step comprises managing said flash ROM by forming extra storage blocks in said flash ROM in addition to the storage blocks to be accessed.

A computer control apparatus for controlling a computer by reading out a predetermined program from a memory medium, wherein said memory medium comprises:

• a procedure code of the managing step of forming a plurality of storage blocks each consisting of a data area and a management area corresponding to the data area in a flash ROM, storing state information indicating a storage state of the data area of each storage block in the management area of the storage block, and managing access to said flash ROM on the basis of the state information;
• a procedure code of the saving step of extracting, from an erase block of said flash ROM, by referring to the state information in the management area, a storage block in which data in the data area is valid, and saving contents of the extracted storage block to the outside of the erase block;
• and
• a procedure code of the erasing step of erasing the erase block after the saving step has saved all storage blocks containing valid data in the erase block,
• wherein the managing step comprises managing said flash ROM by forming extra storage blocks in said flash ROM in addition to the storage blocks to be accessed.

An IC card apparatus which is attached to a host apparatus and to which a data write/read operation can be performed in accordance with a request from said host apparatus, comprising:

• a flash ROM managed by forming a plurality of data areas and management areas corresponding to the data areas in said flash ROM;
• writing means for receiving from said host apparatus a write instruction containing specification information which specifies a data write destination, writing data in one of the data areas, and writing the specification information in a management area corresponding to the data area;
• and
• reading means for receiving from said host apparatus a read instruction containing specification information which specifies a data read source, retrieval-accessing a management area in which the specification information is stored, and reading out data stored in a data region corresponding to the retrieval-accessed management area.

An electronic camera for storing data in a flash ROM, comprising:

• a plurality of data areas and management areas corresponding to the data areas formed in said flash ROM;
• writing means for receiving a write instruction containing specification information which specifies a data write destination, writing data in one of the data areas, and writing the specification information in a management area corresponding to the data area;
• and
• reading means for receiving a read instruction containing specification information which specifies a data read source, retrieval-accessing a management area in which the specification information is stored, and reading out data stored in a data region corresponding to the retrieval-accessed management area.