Debug Change PE State to EL1.
Is an optional 16-bit unsigned immediate, in the range 0 to 65535, defaulting to 0.
Debug Change PE State to EL1 allows the debugger to move the PE into EL1 from a lower Exception Level or to a specific mode at the current Exception Level.
If the PE is at EL1 or lower, then the PE enters EL1h.
If the PE is at an Exception Level higher than EL1, then the PE does not change Exception Level but selects use of the stack pointer for the current Exception Level by updating PSTATE.SP.
This instruction is always UNDEFINED in Non-debug state.
For more information on the operation of this instructions, see DCPS in the ARMv8-A Architecture Reference Manual.