| 摘要 |
PURPOSE:To find out easily and surely a defective microcomputer by applying a common potential to a stand-by input terminal of the microcomputer to stop the microcomputer thereby applying a voltage to a stand-by terminal. CONSTITUTION:A switch 6 is set to solid lines to bring the level of the stand-by terminal 2 of the mounted microcomputer 1 to a common potential to bring an input/output terminal of the mounted microcomputer 1 to a high impedance thereby stopping the microcomputer. Since a potential E is fed to a stand-by terminal 4 of a test microcomputer 3 via a resistor 5, the test microcomputer 3 is brought into the operating state. When the test microcomputer 3 is operated normally and the device mounted by the mounted microcomputer 1 is operated normally, the defective state of the mounted microcomputer 1 is demarcated. When the system is not operated normally even in this state, a defect other than the mounted microcomputer 1 is demarcated. |
