Processor Status Word
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The Processor Status Word or Program Status Word (often given as PS for short, or some variant) is a register in the CPU which records important information about the state of the CPU.
Information typically present in the PS includes:
- whether interrupts are enabled;
- for time-sharing machines, whether the CPU is in 'User' or 'Kernel' mode;
- the condition codes, for machines which keep them in the PS.
Some machines (e.g. the PDP-10) include the Program Counter in the PS.
