Load Program Status Word instruction

In the System/360 line of IBM mainframe computers up to contemporary zSeries, the Load Program Status Word instruction (LPSW) is a privileged instruction used to restore the program status, including the mode and key, and the next sequential instruction address after the interruption. The interruption could be any of a set of interruptions (SVC, I/O, timer/external, etcetera).

LPSW could be considered the complement of any interruption, in general, and an SVC interruption, in particular, as the return from such an interruption is effected by a LPSW instruction.