Abstract: A memory mat is provided separately from a memory mat that is a normal memory area, and data therein cannot be read from the outside. In a page buffer, information input from the outside is stored. A comparing circuit compares security information stored in memory mat with information stored in page buffer, and the comparison result is output to the outside as a status. Even when unauthorized copying is performed, information in memory mat is not copied. Therefore, an external apparatus can easily determine whether or not the semiconductor memory is an unauthorized copy by referring to the status.

Abstract: A communication assisting apparatus is provided for mediating data transfer between a first data processing apparatus and a second data processing apparatus. The communication assisting apparatus includes a first connection unit, a memory and a second connection unit. The first connection unit is connected by wire with the first data processing apparatus, and receives data from the first data processing apparatus. The memory stores therein the data received by the first connection unit. The second connection unit is connected by wireless with the second data processing apparatus, and transmits the data read out from the memory to the second data processing apparatus. The communication assisting apparatus further includes a processing section which reads out the data stored in the memory according to a state of communication with the second data processing apparatus.

Abstract: A refresh zone detection part divides a block of a semiconductor memory into refresh zone units for executing refresh, and detects the refresh zone including the sector of the writing target. A refresh execution part sequentially refreshes the sectors included in the refresh zone detected by refresh zone detection part, every time data is written to a sector. Thus, it is possible to prevent the number of rewritings to a specific sector from increasing, and the refresh can prevent data change due to accumulative disturbance.

Abstract: In a processor (10), an index creating unit 14 creates an index indicating a piece of file management information about a target file to be read from a file name specifying the target file to be read by using a function representing a one-to-one correspondence between file names and indexes. An index and file management information associating unit (15) reads apiece of file management information corresponding to the index created by the index creating unit (14) from a file management information array 13 in which plural pieces of file management information are aligned in ascending order of corresponding indexes, and then acquires a position where the target file to be read specified by the read piece of file management information is stored in a storage unit (30).