Semiconductor storage device and storage controlling method

A semiconductor storage device, comprising:

• a first storage unit that has a plurality of first blocks that are data write regions;
• an instructing unit that issues a write instruction of writing data into the first blocks;
• a converting unit that converts an external address of input data to a memory position in the first block with reference to a conversion table in which external addresses of the data are associated with memory positions of the data in the blocks;
• a managing unit that manages a memory status of the data in the first blocks;
• and
• a judging unit that judges whether the first blocks includes any first block in which data writing would not cause loss of the valid data based on the memory positions of the input data and the memory status of the data, the valid data being the data associated with the external address, wherein
• the instructing unit issues the write instruction of writing the data into the first block in which the data writing would not cause loss of the valid data, when the first blocks include the first block in which the data writing would not cause loss of the valid data.

A storage controlling method implemented in a semiconductor storage device, the method comprising:

• issuing a write instruction of writing data into blocks that are data write regions in a storage unit;
• converting an external address of input data to a memory position in the block with reference to a conversion table in which external addresses of the data are associated with the memory positions of the data in the blocks;
• and
• judging whether any of the blocks store valid data based on the memory positions of the input data, the valid data being the data associated with the external address, wherein
• the issuing issues the write instruction of writing the data into the block in which the valid data is not stored, when it any of the blocks does not store the valid data.