A non-volatile semiconductor memory is disclosed comprising N memory devices each comprising a plurality of blocks, wherein each block comprises a plurality of memory segments accessed through an address. A searched is performed by issuing a read command for each of the N memory devices, wherein an address of each read command is separated by a distance determined in response to the search range of addresses and N, and the search range of addresses is greater than N. Data read from at least one of the memory devices is evaluated to determine whether the search has finished.