Machine with two units of operation.

摘要

A computer system that has a machine unit of operation (MUO) used to time executions in the system, has a User State and a Control State, has multiple domains for logical processors, and and has a Domain Unit of Operation (DUO) to time domain operations in the system. The DUO is used for timing during emulation User instructions a control program in control state. The physical processor is augmented by a DUO control bit that control bit indicates that execution is within a machine unit of operation or a domain unit of operation. The DUO bit is set when a transfer is forced from User State to Control State in order to emulate a user instruction. The DUO bit can be explicitly set or reset by Control Software.