| 摘要 |
PURPOSE:To minimize the number of cables and maximize the transfer capacity of the data, by providing the 1st-5th request lines plus the 1st answer line to secure the transfer of the synchronous data by means of the data bus bar and then displaying the contents of the information on the data bus bar. CONSTITUTION:The system is comprised of information processors (peripheral control unit IOC) 2-5, data transfer control unit (channel device CH) 1, data bus bar 6, the 1st-5th request lines 7-11 plus the 1st answer line 12 each. When the data transfer is started, the start request signal is given from CPU. At the same time, processor 2 detects that the starting has been given by the 1st request line 7, and then prepares for the data transfer. When the data is transferred, both the write and the read data are received through the 2nd and 3rd request lines 8 and 9 respectively. And the transfer end signal is received via the 4th request line 10. After this, unit 1 receives the state report signal through the 5th request line 11, and processors 2-5 perform the state reporting actions continuously and repetivively until they receive the status receivable signal through the 1st answer line 12. |
