| 摘要 |
PURPOSE:To prevent an increase of a loading capacity of a word line by a non-selected memory cell by connecting an end of a drain data line of a respective memory cell opposed to a multiplexer to a pressure reducing circuit and making only the data line of a sense amplifier of the memory cell turned on. CONSTITUTION:A drain of a respective memory cell is connected to a terminal 6 of an intermediate voltage between a power source voltage and an earth voltage by a pressure reducing circuit 101 and opposing sides to a sense amplifier 106 of respective data lines 4-1, 4-2... are connected to the terminal 6 through potential preventing resistances 103-1, 103-2.... Accordingly, only the sides of the amplifier 106 of the data lines 4-1, 4-2... of the selected memory cell become low potential and an electric current passes through the data lines through the terminal 6 to read a memory content of a ROM cell. Both ends of the non-selected data lines 4-1, 4-2 are maintained at high voltage, a channel forming of the non-selected memory cell having a high potential in a source drain is prevented, and without being a loading capacity of the selected word line, a reading is carried out without delay and at high speed. |
