| 摘要 |
PURPOSE:To attain efficient operation of the system by fetching diagnostic mode information designated by a designation means as a status and executing the initial diagnostic processing so as to execute quickly after application of power the user program processing. CONSTITUTION:A microprocessor muP 2 has a means fetching the state of a switch 1 as a status. A ROM 3 has a test routine (TPS) having a short execution time for operating initial program load (IPL) and a high density test routine (TPH) for writing/reading a signal to/from a memory address. The muP 2 checks the status of the switch 1 just after application of power, and since the switch is turned off normally, the TPS routine applies a required minimum initial diagnosis and the step moves to the IPL> If the system is successful to the check just after the manufacture and the required minimum diagnosis but the system will not operate normally afterward, the step is moved to the routine TPH for detailed diagnosis to detect the fault by applying power while depressing the switch 1. |
