| 摘要 |
PURPOSE:To suppress the noise generated to a writing signal when a D/I input signal is switched, by forming a D/I input buffer circuit with two stages of gate and giving the prescribed control to the lower gate to avoid a change of the output signal of the D/I circuit in a reading mode. CONSTITUTION:A D/I input buffer circuit 10 consists of a series gates, and a D/I input signal and a writing instruction signal WE are impressed to the upper and lower gates respectively. When the signal is set at a high level in a reading mode, the emitter follower output of the circuit 10 has no change although the D/I input signal is switched and is kept at a high potential. Therefore the noises are suppressed for writing driving signals VW1 and VW2 which are delivered by a driving signal generating circuit 20 which is controlled by the circuit 10. Thus the working margin of a semiconductor memory cell is increased. |
