| 摘要 |
PURPOSE:To reduce the number of integrated circuits to be added for logical definition by incorporating an external logical gate in one of plural integrated circuits. CONSTITUTION:A logical gate 20 which has been an external logical gate constitutes a logical gate equivalent to the logical gate provided on the outside of an integrated circuit 1 by switching the connection of wiring by means of switching circuits 40 between a reprogram terminal REP, reset terminal RES, and initialized terminal INI and three terminals X, Y, and Z by effectively using a buffer gate 30, OR gate 32, and pull-up resistance R. As a result, a desired logic circuit can be defined by combining and connecting plural integrated circuits and loading data for the program of the logic circuit. Therefore, the number of integrated circuits which have been added to the external logical gate can be reduced and the logic circuit can be reduced in size and improved in reliability. |
