| 摘要 |
PURPOSE:To prevent the breakage of the data on a memory by reporting the abnormal end of data transfer to a program given from a channel device. CONSTITUTION:A channel device 2 detects the generation of a data overrun while transferring data by a data streaming system and therefore sets an FF at 1, for example, to show the generation of the data overrun. When the transfer of data is through, the device 2 checks the unit check bit of a device status byte reported from an input/output controller 3. Then the device 2 sets abnormally the interface control check bit of the channel status byte as long as the FF is kept at 1 although the corresponding check bit is normal and reports this fact to a program. Thus it is possible to prevent the data breakage of a memory caused by the abnormality of an IO interface cable or the controller 3. |
