| 摘要 |
PURPOSE:To obtain a semiconductor integrated circuit which makes the operation of two pieces of input terminals with one piece of input terminal, by providing one piece of input terminal in which a quaternary input is inputted and two pieces of input buffers controlled by quaternary inputs. CONSTITUTION:When an output B1 is used as a signal line, an input high voltage=V1-V2 and input low voltage=V0-V1 are added to an input A1 like as timings of t1-t4. Then, by input-output characteristics of input buffers 22 and 23, an output C1 remains high in level and only the output B1 is changed in accordance with the input A1. When the output C1 is used as a signal line, on the contrary, an input high voltage=V2 and input low voltage=V1-V2 are added to the input A1 like as timings t5-t9. As a result the output B1 remains low in level and only the output C1 is changed in accordance with the input A1. Therefore, a semiconductor integrated circuit which makes the operation of two pieces of input terminals with one piece of input terminal is obtained without requiring any control signal, etc., to the input buffers 22 and 23. |
