Interrupts: Difference between revisions

== S390 Interruptions ==

An exception on the S390 architecture is recognized depending on the context of the instruction.

=== External Interrupt ===

An external interrupt is produced when the CPU timer or an external devices triggers said interrupt.

=== Supervisor Call Interrupt ===

The supervisor call generates an interrupt which will place the current [[PSW]] into the [[PSA Mapping#FLCSOPSW|FLCSOPSW]] (Service Old PSW). Then load the new PSW from [[PSA Mapping#FLCSNPSW|FLCSNPSW]] (Service New PSW). The location of the SVC code is placed at [[PSA Mapping#FLCESICODE|FLCESICODE]]

=== Input/Ouput Interrupt ===

This interrupt is generally triggered when a device completes execution of a command program.

=== Program Check Exception ===

A program exception is recognized when an invalid address is accessed or an invalid instruction is executed.

=== Specification Exception ===

Generally produced when the given arguments or registers to an instruction are invalid.

=== Machine Check Exception ===

Produced when part of the equipment reports a malfunction. Usually means that said device should be replaced and it's up to the user to do that.