10.9.1.8 PCTRAP

In any trap event, the Trap Origination Address register (PCTRAP) is loaded with the value of the PC associated with the instruction that caused the trap. The origination address of a trap is captured in the PCTRAP register, given that the current CPU IPL at the time of the trap is less than eight.

Further PCTRAP updates are blocked after the first PCTRAP address capture, preventing newer traps from overwriting the source address of older ones. The register needs to be written with value 24’h000000 for trap address capture to be re-enabled.

This feature is primarily intended to aid system debugging and to locate the cause of system traps.