The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 23, 2021
Filed:
Jun. 29, 2020
Kioxia Corporation, Minato-ku, JP;
Koichi Shinohara, Fujisawa, JP;
Katsuki Matsudera, Kawasaki, JP;
Ian Christopher Gamara, Yokohama, JP;
Yoshikazu Harada, Kawasaki, JP;
Noritaka Kai, Kawasaki, JP;
Yusuke Tanefusa, Yokohama, JP;
Kioxia Corporation, Minato-ku, JP;
Abstract
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.