| 摘要 |
PURPOSE:To switch between a standby state and selection state without causing a change in the potential present in a common line for the realization of high- speed operations by a method wherein the selection mode is thrown into a WRITE mode or READ mode dependent on the relation of the selection mode to the pattern layout. CONSTITUTION:The first diffusion region 3 is used as a drain in a WRITE operation. A high-tension positive voltage is applied to a bit line 10 and control gate 6 (word line). In a READ operation, a second diffusion region 4 serves as a drain and the first diffusion region 3 as a source, and a prescribed positive READ voltage is applied to the second diffusion region 4 and the control gate 6. The first diffusion region 3 or a bit line 10 is grounded. In a READ mode using a memory cell array, a common line (c) is zero in voltage whether in a stand-by state or selection state. With a method being employed wherein a selection bit line is pulled down prior to selection in a READ mode, the common line (c) carries a prescribed positive voltage Vdr whether in a standby state or selection state. |
