| 摘要 |
A STO stack control system employed in a data processing system which enables dynamic access over a plurality of virtual spaces, and in which the STO stack (4) is retrieved depending upon the contents of a plurality of control registers (CR1, CR7) which specify virtual spaces. In this system when the contents of a given control register (CR1, CR7) are changed to register a new STO identifier (STO.ID) in the STO stack (4) and when it becomes necessary to erase this registration of an old STO.ID due to restriction of the number of ways of the STO stack (4), the old STO.ID is not erased in case the registration thereof is effected on the basis of the virtual space that corresponds to the contents of other control register (CR7, CR1) but, instead, the old STO.ID registered on the basis of the space corresponding to the control register (CR1, CR7) whose contents are changed is erased. |
