| 摘要 |
PURPOSE: An interrupt generator is provided to use all or a part of input signals as a system interrupt, to identify the final output state before an interrupt in a case of interrupting a program and restarting the program, and to check which device has a problem in a case of an occurrence of a communication failure. CONSTITUTION: The device comprises a control signal generator(15), a control register(23), an interrupt mask(17), an interrupt approver(25), an interrupt generator(21), an output feedback circuit(27), an input isolator(11), an input display(13), an output display(29), and an output isolator(31). The control signal generator(15) supplies control signals to the control register(23), the interrupt mask(17), the interrupt approver(25), and the output feedback circuit(27) by using address signals and control signals of a micro controller. The control register(23) latches a data bus by a write signal generated by the control signal generator(15), and the latched signal is used for controlling the output feedback circuit(27) and the interrupt mask(17). The interrupt mask(17) latches the data bus and generates a corresponding mask signal for checking if an input signal is used as an interrupt signal in a case that the control signal generator(15) generates a control signal. The interrupt approver(25) latches the data bus and generates an interrupt approval signal, and the interrupt approval signal makes a clear signal of the interrupt generator(21). The interrupt generator(21) receives the clock signal and the clear signal from the interrupt mask(17) and the interrupt approver(25), and generates a partial interrupt with respect to each input bit. The output feedback circuit(27) feeds an output of the data bus back to an output of a parallel output circuit according to a control signal of the control signal generator(15).
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