Kioxia Corporation

Noritaka Kai

Yoshikazu Harada

Katsuki Matsudera

Yusuke Tanefusa

Koichi Shinohara

Ian Christopher Gamara

According to a certain embodiment, the semiconductor memory device includes a memory cell array, a control circuit, and a data register storing an erase verify fail flag. An erase target block is divided into word line groups. The control circuit includes: a counter configured to count the number of the erase verify fail flags to be output as a count value for each group; a plurality of counter registers configured to store the count value for each group; an arithmetic circuit configured to take a difference of the plurality of count values respectively stored in the plurality of counter registers and to output a result of the difference as a number of second fail flags; and a comparator configured to compare the number of criteria of the erase verify fail flag and the number of the second fail flags to be output as a memory state detected result.

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Kawasaki, Japan

Noritaka Kai