Method for controlling memory card and method for controlling nonvolatile semiconductor memory

Abstract

A method for controlling a memory card which includes a nonvolatile semiconductor memory whose memory area includes a plurality of write areas is disclosed. A first area which is a part of the plurality of write areas is set in accordance with management executed by a first file system. The first file system sequentially writes data along a direction in which addresses of the plurality of write areas increase. A second area which is a part of the plurality of write areas is set in accordance with management executed by a second file system. The second file system writes data in an order which does not depend on the addresses.

1 . A method for controlling a memory card which includes a nonvolatile semiconductor memory whose memory area includes a plurality of write areas, the method comprising: 
 setting a first area which is a part of the plurality of write areas in accordance with management executed by a first file system which sequentially writes data along a direction in which addresses of the plurality of write areas increase; and    setting a second area which is a part of the plurality of write areas in accordance with management executed by a second file system which writes data in an order which does not depend on the addresses.    
   
   
       2 . The method according to  claim 1 , wherein sequentially writing data along a direction in which addresses of the plurality of write areas increase includes continuously writing data in the plurality of write areas having consecutive addresses.  
   
   
       3 . The method according to  claim 1 , wherein the first file system is one of a DVD-R type file system, a DVD-RW type file system, and a DVD-RAM type file system, and 
 the second file system is a FAT file system.    
   
   
       4 . The method according to  claim 1 , wherein a host into which the memory card is inserted sets the first area in accordance with the management executed by the first file system and sets the second area in accordance with the management executed by the second file system.  
   
   
       5 . The method according to  claim 1 , wherein the first area includes an region which a user can use, and the second area includes an region in which management information in the nonvolatile semiconductor memory is stored.  
   
   
       6 . The method according to  claim 1 , wherein a data erasure is performed in units of one of a plurality of erase areas each having a plurality of write areas in the nonvolatile semiconductor memory, and 
 the first file system recognizes a size of the plurality of erase areas and manages data taking the erase area into account.    
   
   
       7 . A method for controlling a nonvolatile semiconductor memory whose memory area includes a plurality of write areas, the method comprising: 
 using a first control method to control the nonvolatile semiconductor memory when writing or reading data to or from a first area which is a part of the plurality of write areas, the first area being set in accordance with management executed by a first file system which sequentially writes data along a direction in which addresses of the plurality of write areas increase; and    using a second control method to control the nonvolatile semiconductor memory when writing or reading data to or from a second area which is a part of the plurality of write areas, the second area being set in accordance with management executed by a second file system which writes data in an order which does not depend on the addresses.    
   
   
       8 . The method according to  claim 7 , wherein the first file system is one of a DVD-R type file system, a DVD-RW type file system, and a DVD-RAM type file system, 
 a data erasure is performed in units of one of a plurality of erase areas each having a plurality of write areas, and    the first control method includes avoiding copying data in one of the plurality of erase areas to another one of the plurality of erase areas.    
   
   
       9 . The method according to  claim 7 , wherein each of the plurality of write areas has a data storage section which stores data and a written state information section which indicates a written state or a free state, and 
 a controller which controls the nonvolatile semiconductor memory writes data to the data storage section of one of the plurality of write areas and writes a written state indication in the written state information section.    
   
   
       10 . The method according to  claim 8 , wherein the written state information section is used to detect one of the plurality of write areas in which data is written.  
   
   
       11 . A method for controlling a nonvolatile semiconductor memory having a plurality of write areas each having a data storage section which stores data and a written state information section which indicates a written state or a free state, the method comprising: 
 sequentially writing data in the plurality of write areas in a direction in which addresses of the plurality of write areas increase, while writing data in the data storage section of one of the plurality of write areas and writing a written state indication in the written state information section.    
   
   
       12 . The method according to  claim 11 , wherein sequentially writing data in the plurality of write areas along a direction in which addresses of the plurality of write areas increase includes continuously writing data in the plurality of write areas having consecutive addresses.  
   
   
       13 . A method for controlling a nonvolatile semiconductor memory whose memory area includes a plurality of write areas, the method comprising: 
 receiving a data moving command containing an instruction on movement of data stored in one of the plurality of write areas to another one of the plurality of write areas; and    executing a process specified by the data moving command by at least either actually moving data using a data copy command and a write area erase command or using a conversion table for conversions between addresses of the plurality of write areas where move target data is stored and addresses of the plurality of write areas where the move target data is to be stored to make an issuer of the data moving command consider that data is moved.    
   
   
       14 . The method according to  claim 13 , wherein a host into which a memory card including the nonvolatile semiconductor memory and a controller controlling the nonvolatile semiconductor memory is inserted issues the data moving command.  
   
   
       15 . A method for controlling a memory card which includes a nonvolatile semiconductor memory whose memory area includes a plurality of write areas, the method comprising: 
 creating a temporary file entry describing a size of an reserved region which is at least a free part of the plurality of write areas and a start position of the reserved region;    writing a file consisting of a plurality of data in the reserved region from the start position; and    when the file has been completely written, determining a size of the file written; and    changing the temporary file entry to a file entry describing the start position and the size of the file.    
   
   
       16 . The method according to  claim 15 , further comprising: 
 when the file has not been completely written, referencing the temporary file entry to recognize the start position;    detecting a final position in the reserved region, in the final position data partly constituting an unfinished file which is a part of the file being written;    determining a size of the unfinished file using the start position and the final position; and    changing the temporary file entry to a final file entry describing the start position and the size of the unfinished file.    
   
   
       17 . The method according to  claim 16 , wherein the reserved region consists of a plurality of write areas having consecutive addresses, and 
 writing the file in the reserved region includes continuously writing data constituting the file in the plurality of write areas having consecutive addresses, along a direction in which the addresses increase.    
   
   
       18 . The method according to  claim 16 , wherein each of the plurality of write areas has a data storage section which stores data and a written state information section which indicates a written state or a free state, and 
 writing the file in the reserved region includes writing data in the data storage section of one of the plurality of write areas and writing a written state indication in the written information section, and    detecting the final position includes referencing the written state information section to detect the final position.