| 摘要 |
Flexible control of storage access keys is facilitated by allowing storage access keys to be specified in user registers, the keys in the user registers overriding storage access keys in system registers. A source access key to control access to a source operand is selected from one of a source user register 608, which is intended to be updated by users, and a system register such as a program status word (PSW) 604, which is not intended to be updated by users. Similarly, a target access key to control access to a target operand is selected from one of a target user register (also intended to be updated) and the system register, the selection being independent of the selection of the source access key. The source and target access keys are used to control access to the source and target operands in carrying out the moving of data from a source address space to a target address space. The access key selection 600 is performed on the basis of a control value 610 of an operand access control 608. The source and target user registers may be the same register. |
