| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To prevent access for a defective block without performing complex file control and to output successively data succeeding to data corresponding to a specified address by only toggle operation of read-enable, in a NAND type flash memory. <P>SOLUTION: Each block of a memory cell array 51 is provided with nonvolatile normal/defective flag storing cells 62 in which a flag for discriminating whether a block is normal or not is recorded, and a normal/defective state discriminating circuit 63 discriminating a normal/defective state of a block based on the flag. When data of the last page of some block is outputted to the out side, it is discriminated whether the next block is normal or not, when it is not normal, discrimination of normal/defective state of the succeeding blocks is performed successively until it reaches a normal block. During the period, access for the memory cell array 51 is prohibited, when it reaches a normal block, reading data from the block is started again. <P>COPYRIGHT: (C)2004,JPO</p> |
