| 摘要 |
PURPOSE:To start the next data transfer after the end of the current data transfer by transmitting input/output device addresses and subsequent control information groups to input/output controllers from a central controller without waiting for the end of the current data transfer. CONSTITUTION:An input/output controller 40 is connected to a central controller 1 and a main storage device 2 via a common bus 3, and controls data transfer between two input/output devices 51, 52 under its control and the device 2. Three sets of control information groups CW or the like for the data transfer to be successively executed after the end of the current data transfer are stored in the control register groups 403-405 of the controller 40. When the cntrol information group CW0 from the controller 1 is stored in a register group 403, it is accumulated in a work register group 406. If the input/output addresses therein discriminate the assignment of the device 51 via a decoder 407, the corresponding gate 408 is turned on and the data transfer is accomplished. If the chain command in the control ininformation is 1, the subsequent control information groups are read out after the end of the data transfer thereof and the next transfer is started. |
