| 摘要 |
PURPOSE:To process memory access with the highest priority even when a memory bank of a requesting destination is in busy by energizing the highest priority request signal in a channel control device in which urgent memory access is made necessary. CONSTITUTION:In a channel control device CHP1, when the preparation of data to be urgently transferred is completed, by energizing the highest priority request HI-RQ signal, a latch 120 is turned on in correspondence to a port 12 and sent to the highest priority control circuit 6. Even when a memory bank of a data transfer requesting destination is in busy, the port 12 is selected in a selecting circuit 2 at the circuit 6 with the highest priority and inputted through a port 3 to a selecting circuit 5. Even in the circuit 5, the circuit 6 operates to select the port 12 with the highest priority even when the memory bank of the requesting destination is in busy. As the result, when the memory bank does not go in busy, the circuit 6 controls the circuit 5 and a memory access request from the selected CHP1 can access a memory with priority. |
