| 摘要 |
PURPOSE:To cancel the deterioration of processing ability by simulating a signal from an external device when a diagnostic mode register is set from a service processor, and diagnosing a channel interface control circuit to control an interface. CONSTITUTION:When a diagnostic mode register 140 is set from a central control unit CCU 2 or a service processor SVP 3, the signal from an external device 6 is simulated, the contents of interfaces 11 and 12 are read, and hardware 13 to control interfaces 8, 10, 11 and 12 are diagnosed. Thus, a necessity to define an input/output instruction for the diagnosis on a central control unit CCU side is eliminated, and the processing ability of the central control unit CCU can be enhanced. Further, since the constitution of the firmware of a channel adapter CA is simplified, the reliability of the title data processor can be enhanced. |
