| 摘要 |
PURPOSE:To prevent malfunctions by outputting a reset signal from the microprocessor of a system and inhibiting the output of a latch when a board loading on output port is set into a working system. CONSTITUTION:When a system is started and a board loading the output port is set into the working system, the reset signal is outputted from the microprocessor of the system to reset the FF1 and FF2. As a result, the output of an n-bit shift register 11 is reset and the output of an n-bit latch is inhibited. In outputting the data, a start clock is changed to 'H', 'L' and 'H' to release a reset state. As a result, no erroneous data is outputted and the next normal data and subsequent ones can be outputted even when an output port is activated in the writing state of the serial data. |
