| 摘要 |
<p>PURPOSE:To reduce the input/output process that is performed by a program, by selecting a specified address line of a RAM, then carrying out the writing control of a data. CONSTITUTION:The data are applied to input ports 121-124, and at the same time an address line 323 is selected. Under such conditions, the data write control signal W is supplied to an AND gate circuit 33. Thus the output signal of the circuit 33 is set at a high level. When this high-level output signal is applied to each control input terminal, tri-state buffer circuits 341-344 open respectively. Then the data applied to the ports 121-124 are transmitted to data lines 311-314 respectively and furthermore to an inner bus line 5. Thus the reading of data is carried out.</p> |
