| 摘要 |
<p>PURPOSE:To surely transmit the potential at a bit line to a selected memory cell by utilizing the electron discharge from a floating gate as an erase mode and electron injection into the floating gate as a writing mode. CONSTITUTION:At the time of erasing the data of memory cells M1-M8, the threshold level is moved toward the negative side by discharging electrons in floating gates 41-48 of the memory cells to a substrate or drain. In other words, data of all memory cells are set to '1'. The erasing operations are performed from the memory cell M1 nearest to a bit line BL. Data writing in the memory cells M1-M8, on the other hand, is performed by moving the threshold level toward the positive side by successively injecting electrons into the floating gates 41-48 from the memory cell M8 farthest from the bit line BL. Therefore, the potential at the bit line can be transmitted surely.</p> |
