| 摘要 |
PURPOSE:To supply an idle address in a simple and quick way, by using a tag memory that discriminates the storage unit with which the reference is through in case a buffer memory which stores the idle address has no vacancy. CONSTITUTION:When a data is stored to a storage unit, the reference number of the storage unit is set to a region corresponding to a reference number memory RCM and then replaced every time the storage unit is referred to. For the storage unit with which the reference number is set zero, the address of the storage unit is stored in a buffer memory BFM if this memory has vacancy. In case no vacancy exists in the memory BFM, a tag 1 is set to the corresponding region of a tag memory TAG. When the memory BFM has vacancy, the memory TAG is retrieved. Then the address of the memory TAG where the tag 1 is set is stored in the memory BFM. As a result, the address of the storage unit having the reference number set zero is immediately stored in the memory BFM without retrieving the storage unit. Thus an idle address can be supplied in a simple and quick way. |
