发明授权
- 专利标题: Nonvolatile semiconductor memory
- 专利标题(中): 非易失性半导体存储器
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申请号: US11606025申请日: 2006-11-30
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公开(公告)号: US07414909B2公开(公告)日: 2008-08-19
- 发明人: Kazuyoshi Okamoto , Kazumasa Yanagisawa
- 申请人: Kazuyoshi Okamoto , Kazumasa Yanagisawa
- 申请人地址: JP Tokyo
- 专利权人: Renesas Technology Corp.
- 当前专利权人: Renesas Technology Corp.
- 当前专利权人地址: JP Tokyo
- 代理机构: Miles & Stockbridge P.C.
- 优先权: JP2005-352384 20051206
- 主分类号: G11C7/02
- IPC分类号: G11C7/02
摘要:
There is provided a high-density mask ROM operable at a high speed. With the mask ROM, respective source lines are disposed so as to be shared by memory cells in respective columns adjacent to each other, and bit lines are disposed so as to correspond to the respective columns of the memory cells. Further, the dummy cells are disposed for the respective columns of the memory cells. The dummy cells are each made up of a series-circuit including a first switching transistor that is turned into the conducting state in response to a signal potential on a dummy word line (DWL), and a second switching transistor 17 for coupling an adjacent source line to the bit line corresponding thereto in response to a potential of the source line in a column corresponding thereto. The memory cells each are made up of one unit of a transistor and a data storage formed by mask wiring. At the time of reading data, a potential of the source line in a select column is caused to undergo a change, whereupon there occurs a potential difference between a pair made up of the bit line as selected to which the memory cells as selected are coupled, and a reference bit line with the dummy cells coupled thereto, so that it is possible to execute readout of data by detecting the potential difference.
公开/授权文献
- US20070127302A1 Nonvolatile semiconductor memory 公开/授权日:2007-06-07