| 摘要 |
PURPOSE:To improve a throughput of a channel processor and to prevent the overrunning by checking the key and simultaneously preheating in a main memory access from the channel. CONSTITUTION:When a fetching access is executed from a channel processor, the data of an operation code, an address, etc., are set to a channel address register 40. When the fetching access needs a key checking, the request of the key checking is performed through a tag reading register 42 to a key access control circuit, and the fetching address is set at a prefetching port 46. Thus, the prefetching is executed, and the operation after key checking is completed almost without the waiting time. In such a way, since the prefetching is executed in parallel to the execution of the key checking, the throughput of the channel processor is improved, and with regard to this, the overrunning of the channel processor can be prevented. |
