| 摘要 |
PURPOSE:To reduce the cost of a dynamic memory device and improve the reliability by connecting a resistance in series between D-RAM and a data bus for writing or reading data in and out of this D-RAM, and preventing reflection. CONSTITUTION:A resistance 43 is connected in series to the line which connects the input terminal DIN of D-RAM16 and the corresponding output side D0 of a data bus in the dynamic memory device, and a resistance 44 is connected in series to the line connecting the output terminal DOUT of D-RAM16 and the corresponding input side D1 of the data bus buffer 30. When the values of those resistances 43 and 44 are too small, noise is not suppressed sufficiently. On the other hand, when the values are too large, data are not transferred in a short time. For the purpose, the values of both resistances 43 and 44 are set to 100OMEGA and the output of a data bus or output impedance of the output side of D-RAM 16 is matched. Consequently, it is evident from an output waveform that the generation of noise is suppressed effectively. |
