SLIP ignores — that is, does not process — PER events
if:
- The PER interrupt occurred while DAT was off. SLIP PER support
applies only to virtual addresses.
- The PER interrupt is redundant. See Principles of Operation for a description of redundant PER interrupts.
- The PER interrupt occurred, but an enabled non-IGNORE PER trap
does not exist. SLIP does the following:
- Ignores a PER interrupt caused by a non-SLIP tool that set up
the PER control registers.
- Turns off the PER bit in the resume PSW before returning to the
first level interrupt handler (FLIH) for program checks. When the
PER bit is off, the SLIP trap will not match.