SEMICONDUCTOR MEMORY UNIT AND DATA READ METHOD USED FOR THE UNIT

摘要

PROBLEM TO BE SOLVED: To provide a non-voltage semiconductor memory unit, which can read data of a spare memory cell array with priority to a main memory array in which a physical address of a memory cell array comprising NAND structure, is precedent and to provide data reading method used for the unit. SOLUTION: In a non-volatile semiconductor memory, provided with a memory cell array having a main memory array 10 and a spare memory array 20 comprising a plurality of NAND cell strings, and a data read method used for the memory, even when the physical address of the main memory array 10 is in front of a physical address of the spare memory array 20, data stored in the spare memory array 20 is read with priority to data of the main memory array 10 by specifying, so that the logical address of the spare memory array 20 is in front of a logical address of the main memory array 10, responding to an external command entering into a spare start whole page sequential read-mode.