| 摘要 |
PURPOSE:To improve the system reliability by supplying the outputs of a hardwear fault detecting circuit and a power supply reset circuit to a NAND circuit to select a microcomputer system by the output. CONSTITUTION:Both using and spare microcomputer systems 1 and 1' receive the input signals through an input port 5 respectively and perform the same actuation. However the output signal fed from the system 1' is not transmitted by an output signal control circuit 7. When a fault of the system 1 is detected by a hardware fault detecting circuit 8, the output of a 3-input NAND circuit 11 is set at ''0'' by the output signal of the circuit 8. Then a flip-flop circuit is inverted. As a result, no output signal is transmitted from the system 1, and the output signal of the system 1' is transmitted. This state is displayed by light emitting diodes 10 and 16. |
