Memory system

A memory system, comprising:

• a non-volatile semiconductor memory including a plurality of blocks;
• and
• a controller configured to control the writing of data to the non-volatile semiconductor memory, the controller including:
• a host I/F control interface configured to receive write command information including file allocation indicating a location for write data,
• a file information management unit configured to assign an erasure level to a file corresponding to the file allocation information and output a file identifier in which a file name, a file size, and the erasure level are combined,
• a flash translation layer unit configured to allocate each file to a block based on the write command information and the file identifier,
• an operation mode setting unit configured to set a threshold value for switching an operation mode of the flash translation layer unit, the threshold value corresponding to a number of available free blocks in the non-volatile semiconductor memory, and
• a comparator configured to output an operation mode signal to the flash translation layer unit based on the threshold value set by the operation mode switching unit and the number of available free blocks from the flash translation layer unit, the operation mode signal indicating a first operation mode in which each file is allocated on a one file per block basis when the number of available free blocks is at or above the threshold value or a second operation mode in which different files can be allocated to the same block when the number of available free blocks is below the threshold value.

A memory system, comprising:

• a non-volatile semiconductor memory including a plurality of blocks;
• and
• a controller configured to:
• receive write command information including file allocation information indicating a location for write data,
• assign an erasure level to a file corresponding to the file allocation information and output a file identifier in which a file name, a file size, and the erasure level of the file are combined, and
• allocate one file per block based on the write command information and the file identifier.