Nonvolatile memory card

摘要

The present invention provides a memory card in which stored information is not lost undesirably even when an operation power source is shut down during an erasing/writing process. A nonvolatile memory has an erase table in which a free-space information flag is associated with each physical address of a memory area and an address translation table in which a physical address of a memory area is associated with each logical address. The free-space information flag indicates whether a corresponding memory area is permitted to be erased or not. A control circuit determines a memory area to which rewrite data is to be written by referring to the free-space information flag of the erase table, reflects the physical address and the logical address of the memory area to which the data is written into the address translation table, and updates the free-space information flag of the erase table. The memory area to which rewrite data is to be written is determined by referring to the free-space information flag of the erase table, and rewriting is not performed in the same memory area.