| 摘要 |
PURPOSE:To increase the amount of information of input signals and to provide a new function to a digital system, by providing an intemediate level state in addition to high and low level states, and detecting also the intermediate level state. CONSTITUTION:An input signal In is given to a logical circuit 13 through two inverting type input buffer circuits 11, 12 having different threshold voltage state. The logical circuit 13 performs a prescribed logical operation. When the levels of the input signal In are VDD-VIH1, levels of low; high; high are obtained at outputs A, B, C of the circuit 13, and when the levels of the In are intermediate level of VIL1-VIH2, and VIL2-GND, high; high; low and high; low; high levels are obtained at the outputs A, B, C, allowing to discriminate the high; intemediate; low, three levels of the input signal In. |
