| 摘要 |
PURPOSE:To prevent the malfunctions due to the fluctuation of levels of a power line and a ground GND line which are caused by a large current by detecting that the output levels of plural logical gates is changed in the same direction and switching the working speed of the output circuit of each logical gate. CONSTITUTION:The output signals of a data selector 2 are supplied to the input terminals of output circuits 13-1 to 13-4 and also to the input terminal of a detecting circuit 14 consisting of an exclusive NOR circuit. The control terminals CI of the circuits 13-1 to 13-4 are connected to the output terminal of the circuit 14. When all output signals of the selector 2 are set in the same direction, the terminals CI of the output circuits 13-1 to 13-4 are set at 'H' levels to reduce the transient current value although the working speed is deteriorated. Thus it is possible to prevent the deflection of both a power supply and a GND caused by a simultaneous ON state. As a result, the malfunctions are never produced. |
