| 摘要 |
PURPOSE:To make a useless period for an access unnecessary by making a main storage accessible for each processing device in case of a main storage segment is locked to its own processing device, with respect to a main storage access request. CONSTITUTION:As for a main storage access request from each processing device, only one request is selected by a priority order determining circuit 10, and the selected request is set to a lock request register 11 together with a lock request. On the other hand, when a main storage address is set to an address register 13, a lock status word is read out to a register 15 from a lock array 14. In a lock deciding circuit 16, if the selected request is sent to a main storage segment locked already by other processing device, an execution of its request is inhibited, and if it is that which is locked by the own processing device, its request is received, and an access to the main storage is executed. |
