| 摘要 |
PURPOSE:To insure a digit line against being charged up on a high level unnecessarily by detecting the level of the digit line and stopping the output of a precharge signal the moment the level reaches the prescribed one. CONSTITUTION:When a precharging action starts and the level of the digit line rises, due to the high level of the precharging action an NMOS transistor 34 maintains the on-state, and accordingly the level of a line 31 and that of the 3rd input in an OR circuit 37 also rise. When the level of the digit line 23 reaches the level to switch the OR circuit 37, its output is switched to a high level from a low one (becomes the state where the output of the precharging signal is stopped), and as a result precharging transistors 28 and 29 are turned off to terminate precharging. Thus such a case can be prevented that the digit line is precharged on a high level unnecessarily, thereby speeding up the action. |
