| 摘要 |
PURPOSE:To remove restriction of the circuit constitution of the outside of an integrated circuit, the wiring layout of a substrate, etc. by discriminating whether a control terminal is in the controlling status or not by the connection/ disconnection of the control terminal to/from an external circuit and forming a control signal controlling internal circuit of the integrated circuit. CONSTITUTION:The integrated circuit is constituted by the control terminal, a three-state detecting circuit for detecting the potential status of said terminal and a discriminating circuit for discriminating the status of the control terminal by an output signal from the three-state detecting circuit. The combination of the output signal states of latch circuits 18, 19 consists of the floating (H, L) of the control terminal 10, the H level (H, H) of the control terminal 10 and the low level (L, L) of the control terminal 10. When the control terminal 10 is floated, the output signal of an EXOR circuit 12 is turned to the H level, and when the control terminal 10 is turned to the H or L level, the output signal of the EXOR circuit 12 is turned to the L level. Therefore, the floating state can be discriminated by applying potential, any one of H or L level, to the control terminal 10. Namely, restriction to controlling potential is removed. |
