| 摘要 |
PURPOSE:To simply cancel a CU busy or unit check condition which is not cancelled but remains by detecting a time-out when the activation is applied for a channel path unit and recognizing that a path busy condition or the like is left and resetting the condition by a channel processor. CONSTITUTION:When the channel processor 3 checks whether the activation can be executed to an I/O device 10 or not, it refers to a control word 12. At this time, when the presence of the unit check condition is recognized, the channel processor 3 recognizes that this condition is maintained for more than a constant time by the value of a time stamp 16. Further, the channel processor 3 checks whether a sense time out function is provided or not in a control unit by a control bit 13 and if this control bit is turned ON, a control bit 15 is reset and the control unit can be used by the I/O device 10. |
