Circuit arrangement for multiplexing an input function and an output function at a single terminal

摘要

A circuit arrangement is provided for multiplexing an input signal and an output signal through a single circuit terminal. Means are coupled to the terminal for selectively applying first input signals to the terminal of a signal level included within a first range of signal levels. Means including a first transistor having an input electrode coupled to a second signal source and an output electrode coupled to the terminal are provided for developing, in the absence of the first input signals, output signals at the terminal which occupy a second range of signal levels which is exclusive of the first range. A second transistor has an input electrode coupled to the terminal and an output electrode, and is biased to be responsive to signals at the terminal which occupy the first range of signal levels.