External aborts are defined as those that occur in the memory system rather than those that the MMU detects. Normally, external memory aborts are rare. External aborts are caused by errors flagged to the external interface.
When an external abort to the external interface occurs on an access for a translation table walk access, the MMU returns a synchronous external abort. For a load multiple or store multiple operation, the address captured in the fault address register is that of the address that generated the synchronous external abort.
See the Arm® Architecture Reference Manual Armv8, for Armv8-A architecture profile for more information.