HIGH IMPEDANCE CONTROL CIRCUIT

PURPOSE: To provide a high impedance circuit for preventing circuit malfunctions based on transition time until a high impedance state is state-established by a pull-up/pull-down resistor in a digital circuit. CONSTITUTION: In the digital circuit provided with an output part 2 whose output side is connected to a signal line 1 and a signal processing part 3 whose input side is connected to the signal line 1 in which the signal line 1 is turned to a high impedance state at the time of the non-output of the output part 2 and logic in the signal line 1 is established by the pull-up/pull-down resistor 4 connected to the signal line 1, a compensation time counting part 5 is provided; the time longer than the transition time after the output part 2 is turned to a non-output state until the logic of the signal line 1 is established is counted and the logic state of input signals in the signal processing part 3 is decided by the output of signals for indicating the end of counting in the compensation time counting part 5.