摘要 |
In a CCW fetching section, for each input/output device being a control objective, a result prediction table in which prediction values of status values to be returned from an input/output device as execution results of CCW commands, is referred to. Then, based on the prediction values, commands being pre-fetching objectives are pre-fetched from a CCW program stored in a memory, and transmitted to a CCW executing section. On the other hand, in the CCW executing section, the pre-fetched commands are sequentially executed, and the actual status values as the execution results are received from the input/output device. Then, when the received actual status values are not same as the predicted status values, success or failure in prediction is notified to the CCW fetching section, and also, the result prediction table is updated in the CCW fetching section.
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