Method, device, and program for managing a flash memory for mass storage

Abstract

The invention relates to a method for controlling a flash memory ( 9 ), which is comprised by a secondary unit of a communications device ( 2 ) which can be connected to a host ( 1 ) and, for mass storage, is written with data (SS 1 , SSN, SS 1 N, SA, BE, S 1 N, S 1 ML) to be stored. According to the invention, the flash memory ( 9 ) is subdivided into blocks ( 10 ) which each comprise storage units (S 1 -SN), and a storage unit (SS 1 ) that has been written to can only be written to again if, before writing to the storage unit (SS 1 ), all the storage units (S 1 , S 2 , SS 1 , SN) of the block ( 10 ) of the storage unit (SS 1 ) to be written to are erased. The flash memory ( 9 ) is controlled in such a way that at least some storage units (S 1 -SN) which are to be written to and the data (SG, SS 1 N, SAI, BEI, S 1 MLG) of said units is unchanged after being written to as compared with before being written to are neither erased nor written to, and at least some erased storage units (S, SG, SDG, SMG) which are to be written to and the data (SG) of said units is changed after being written to as compared with before being written to, are written to with the data to be stored (SS 1 N, BEI, S 1 NI) without being erased again.

We claim: 
     
         1 - 10 . (canceled) 
     
     
         11 . A method for managing a flash memory, wherein the flash memory is included in a communication device that can be connected to a host, and wherein data to be stored are written for mass storage on the flash memory the method comprising,
 dividing the flash memory into blocks, each block containing storage units,   rewriting a storage unit if all storage units in the block of the storage unit to be written to are erased before the storage unit is written to;   managing the flash memory to avoid erasure of and writing to at least some of the storage unit; and   writing to at least some of the erased and to be written storage units, whose data are different after rewriting compared to before rewriting, with data to be stored without re-erasing.   
     
     
         12 . The method of  claim 11  further comprising, wherein the communication device is connected to the host via an interface calling information about a volume of data to be transferred from the host to the flash memory through the communication device from the interface and managing the flash memory with information. 
     
     
         13 . The method of  claim 12 , comprising transferring the information about the data from the host to the flash memory by a mass storage protocol. 
     
     
         14 . The method of  claim 13 , wherein the mass storage protocol is a USB mass storage protocol. 
     
     
         15 . The method of  claim 12 , comprising providing by the interface information about a number of consecutive storage units to be written to, in which the data to be transferred (SSN, SS 1 N, SA, BE, S 1 N, S 1 ML) are to be written. 
     
     
         16 . The method of  claim 15 , comprising providing, by the interface additional information about a number of storage units following a first storage unit. 
     
     
         17 . The method of  claim 12 , comprising inverting data transferred from the host that are to be written to at least one storage unit of a block of the flash memory before the data is written to at least one storage unit. 
     
     
         18 . The method of  claim 17 , comprising, for multiple storage units to be written to, in which the data to be transferred are to be written, inverting the data for all storage units. 
     
     
         19 . The method of  claim 17 , wherein unused bytes of data from the host that are to be written to the flash memory have the hexadecimal value 0x00 when placed in the interface, and have the hexadecimal value 0xFF of an erased byte in the flash memory after inversion, and, instead of writing the hexadecimal value 0xFF into an erased storage unit, the erased storage unit is kept in its erased status without re-erasing. 
     
     
         20 . A computer-readable storage medium include an executable program that, when executed, carries out the method of  claim 11 . 
     
     
         21 . A communication device comprising the computer-readable storage medium of  claim 20 .