| 摘要 |
PURPOSE:To supervise always the hardware and to detect a fault in advance even during continuous operation by providing a timer means and starting the self-diagnosis device utilizing a microprogram at each prescribed period. CONSTITUTION:A clock circuit 310 counts a prescribed time while an interface controller is operated and a diagnostic service routine is started. An output of the circuit 310 is fed to a microprogram control circuit 114 by a diagnosis start control circuit 312 on the condition that no processing requests comes from an external device at the start of the diagnostic service routine. A driver receiver circuit 112 is set at the same time in such a case so that the content of the output data register 305 is reflected to an input data register 306. In the operation of the diagnostic service routine, after a diagnostic saving area of a RAM circuit 16 is tested at first, the operating state of an interface control device before the start of diagnosis is stored in the saving area of the circuit 116. Succeedingly, a pseudo data generating circuit 313 is used to test the data transfer system. The result is decided by the diagnostic service routine and if there is any inconvenience, it is informed to the CPU. |
