| 摘要 |
<p>PURPOSE:To ensure a highly reliable operation for an address buffer circuit by a method wherein a noise generated in the output buffer circuit in operation is prevented from entering the address buffer circuit in a device provided with an output buffer circuit and address buffer circuit connected to one and the same bonding pad. CONSTITUTION:First power source wirings 13 and 15 to supply prescribed power voltages to a second address buffer circuit and second power source wirings 12 and 14 to supply prescribed power voltages to a second output buffer circuit arc provided. Accordingly, even in an asynchronous system wherein the read of address signals and that of data signals are performed not timed to each other, a power source noise, which is generated in the power source wirings 12 and 14 owing to a current through an output buffer circuit (MISFETs 360 and 370) in operation in a selective input/output circuit 300, will not enter the power source wirings 13 and 15 for an address buffer circuit (MISFETs 330 and 340) in the selective input/output circuit 300 and cause the address buffer circuit to operate erroneously. In this way, an address buffer circuit, connected to a bonding pad 5 whereto an output buffer circuit is connected, is ensured of a reliable operation.</p> |
