| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a memory system capable of ensuring both of high storage capacity and high writing speed. <P>SOLUTION: A semiconductor memory 6 includes a plurality of storage areas each comprising a plurality of groups of storage elements, and has a function for storing data of one or more bits in each of the storage elements and a function for selecting either of a first write mode, in which data of n (n represents a natural number) bits are stored in each of the storage elements, or a second write mode, in which data of n+1 or more bits are stored in each of the storage elements, for each of the storage areas. A controller 7 instructs the semiconductor memory to store data, for each of a plurality of logical address groups each composed of a plurality of logical addresses belonging to a specific range, by writing a part of the data allocated with the logical addresses included in the logical address group in a first number of the storage areas in a first write mode and writing another part of the data in a second number of the storage areas in a second write mode. <P>COPYRIGHT: (C)2009,JPO&INPIT |
