| 摘要 |
PROBLEM TO BE SOLVED: To solve such a problem that the waiting time of processing time can not be shortened and also too much load is applied to a system since the pre-reading based on an input-output instruction is not properly performed. SOLUTION: A statistic information buffer 33 stores statistic information corresponding to input-output devices 21 and 22. When an input-output instruction is received, the instruction classification and address information, information showing whether or not the request data on an execution instruction are included in the data acquired by a pre-reading operation, information showing whether or not the address of the input-output instruction is continuous with the execution address of an input-output instruction that is precedently executed, and information showing the continuation value are recorded on the buffer 33 as the statistic information. A pre-reading controller 32 compares a part or the whole of statistic information of the buffer 33 with the address and type of the input-output instruction when this instruction is executed and judges whether the pre-reading operation is effective to the input-output instruction to be executed. Then the controller 32 decides the quantity of data which are acquired by the pre-reading operation when this pre-reading operation is judged to be effective to the input-output instruction.
|
