| 摘要 |
<p>PURPOSE:To improve efficiency for data processing by reading out data, which are latched to an output data latch circuit, to an internal data bus even when an input/output port part is operated either as an input port or an output port. CONSTITUTION:A read data selecting circuit 80 respectively connects first and second input terminals 80A and 80B to the output terminal and input/output port terminal 40 of an output data latch circuit 20 and under the control of a read data select signal Ss, the level value of the output terminal in the output data latch circuit 20 or the level value of the input/output port terminal 40 is outputted to an output terminal 80C. The input/output port part is connected to the output terminal 80C and an internal data bus 10 and equipped with a read gate circuit 70 for which continuity and non-continuity is controlled by a read instruction signal RD. Thus, the input/output port part is operated as the output port and output data D0 latched by the output data latch circuit 20 can be read out to the internal data bus 10.</p> |
