| 摘要 |
PURPOSE:To reduce occurrence of overrun of data, by outputting priority-added data transfer requests in accordance with the kind of I/O devices and using condition of a buffer. CONSTITUTION:At the time of system initialization, an I/O device kind displaying circuit 47 is set from a channel controlling section 3 through a bus 113 and displays the kind of I/O devices connected with a channel device 4. When, for example, a high-speed device or a device which tends to produce overrun of data is connected, the circuit 47 is set to '1'. The setting signal 112 of the I/O device kind displaying circuit 47 is inputted in a decoder 45 through an OR gate 46. The OR gate 46 inputs the OR of the 2nd signal 109b of a register 44 and setting signal 112 in the decoder 45. |
