Abstract: A failure region is specified when a failure occurs in a non-volatile semiconductor memory. When a device controller reads data stored in a specific page in a plurality of non-volatile semiconductor memories to detect an uncorrectable error (UE) of the data stored in the specific page, the device controller executes a diagnosis process including specifying a specific storage circuit that is a storage circuit including the specific page, reading data stored in a part of blocks of the specific storage circuit, and specifying, on the basis of a result of reading data stored in the block, a failure region in the specific storage circuit.

Abstract: A failure region is specified when a failure occurs in a non-volatile semiconductor memory. When a device controller reads data stored in a specific page in a plurality of non-volatile semiconductor memories to detect an uncorrectable error (UE) of the data stored in the specific page, the device controller executes a diagnosis process including specifying a specific storage circuit that is a storage circuit including the specific page, reading data stored in a part of blocks of the specific storage circuit, and specifying, on the basis of a result of reading data stored in the block, a failure region in the specific storage circuit.

Abstract: A copolycondensation of a phenol, a naphthol and formaldehyde proceeds smoothly in the presence of an acid and a metallic element selected from the group consisting of transition metallic elements and metallic elements of Group IIa, Group IIIa, Group IVa, Group Va and Group VIa of the Periodic Table, and a naphthol-modified phenolic resin which has a large molecular weight and does not gel is obtained.