Invention Grant
- Patent Title: Semiconductor memory device and memory state detecting method
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Application No.: US16914733Application Date: 2020-06-29
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Publication No.: US11183256B2Publication Date: 2021-11-23
- Inventor: Koichi Shinohara , Katsuki Matsudera , Ian Christopher Gamara , Yoshikazu Harada , Noritaka Kai , Yusuke Tanefusa
- Applicant: Kioxia Corporation
- Applicant Address: JP Minato-ku
- Assignee: Kioxia Corporation
- Current Assignee: Kioxia Corporation
- Current Assignee Address: JP Minato-ku
- Agency: Oblon, McClelland, Maier & Neustadt, L.L.P.
- Priority: JPJP2019-166809 20190913
- Main IPC: G11C16/04
- IPC: G11C16/04 ; G11C16/34 ; G11C16/14 ; G11C16/08 ; G06F9/30 ; G11C16/24

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.
Public/Granted literature
- US20210082531A1 SEMICONDUCTOR MEMORY DEVICE AND MEMORY STATE DETECTING METHOD Public/Granted day:2021-03-18
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