发明名称 |
Variable capacity semiconductor memory device |
摘要 |
The invention provides a semiconductor memory capable of realizing an efficient use of a memory area and reducing manufacturing costs. A memory has a memory cell array comprising a matrix of cells for electrically storing data. The memory cell array is divided into a plurality of block areas. Each block area is set to a four-valued area for recording the data as four-valued data or a binary area for recording the data as binary data. On an access to a memory cell (writing or reading of the data), a word line voltage for writing or a sense amplifier for reading is switched in accordance with whether the data to be accessed is the binary data or the four-valued data.
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申请公布号 |
US6496409(B2) |
申请公布日期 |
2002.12.17 |
申请号 |
US20000620719 |
申请日期 |
2000.07.20 |
申请人 |
MITSUBISHI DENKI KABUSHIKI KAISHA |
发明人 |
KOBAYASHI SHINICHI;KAI YOSHIHIDE |
分类号 |
G11C16/06;G11C8/08;G11C11/56;G11C16/02;G11C16/08;(IPC1-7):G11C16/04 |
主分类号 |
G11C16/06 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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