| 摘要 |
PURPOSE:To quickly discover a fault by switching the control signal of a paralell interface and data to either a peripheral device or an internal control circuit with a switching circuit. CONSTITUTION:A switching circuit 4 and an internal control circuit 5 are provided so that connection between a parallel interface 2 and a peripheral device 3 can be switched to connection between the parallel interface 2 and internal control circuit 5 by the switching circuit 4 and the exchange of the data can be executed between a CPU 1 and the internal control circuit 5 through the parallel interface 2, switching circuit 4 and data lines 6-9 when operational defect is generated. Thus, it can be decided whether the operation defect is generated on the CPU 1 side or not. |
