DCPS3 Debug Change PE State to EL3 Debug Change PE State to EL3 allows the debugger to move the PE into EL3 from a lower Exception level or to a specific mode at the current Exception level. DCPS3 is UNDEFINED if any of: The PE is in Non-debug state. EL3 is not implemented. EDSCR.SDD is set to 1. When the PE executes DCPS3: If EL3 is using AArch32, the PE enters Monitor mode and LR_mon, SPSR_mon, DLR and DSPSR become UNKNOWN. If DCPS3 is executed in Monitor mode, SCR.NS is cleared to 0. If EL3 is using AArch64, the PE enters EL3 using AArch64, selects SP_EL3, and ELR_EL3, ESR_EL3, SPSR_EL3, DLR_EL0 and DSPSR_EL0 become UNKNOWN. For more information on the operation of the DCPS<n> instructions, see DCPS. 1 1 1 1 0 1 1 1 1 0 0 0 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 DCPS3 if !HaveEL(EL3) then Undefined(); end; if !Halted() || EDSCR().SDD == '1' then Undefined(); end; if ELUsingAArch32(EL3) then let from_secure : boolean = (CurrentSecurityState() == SS_Secure); if PSTATE.M == M32_Monitor then SCR().NS = '0'; end; AArch32_WriteMode(M32_Monitor); if IsFeatureImplemented(FEAT_PAN) then if !from_secure then PSTATE.PAN = '0'; elsif SCTLR().SPAN == '0' then PSTATE.PAN = '1'; end; end; PSTATE.E = SCTLR().EE; LR_mon = ARBITRARY : bits(32); SPSR_mon() = ARBITRARY : bits(32); DLR() = ARBITRARY : bits(32); DSPSR() = ARBITRARY : bits(32); else // Targeting EL3 using AArch64 AArch64_MaybeZeroRegisterUppers(); MaybeZeroSVEUppers(EL3); PSTATE.nRW = '0'; PSTATE.SP = '1'; PSTATE.EL = EL3; if IsFeatureImplemented(FEAT_UAO) then PSTATE.UAO = '0'; end; ELR_EL3() = ARBITRARY : bits(64); ESR_EL3() = ARBITRARY : bits(64); SPSR_EL3() = ARBITRARY : bits(64); DLR_EL0() = ARBITRARY : bits(64); DSPSR_EL0() = ARBITRARY : bits(64); var sync_errors : boolean = IsFeatureImplemented(FEAT_IESB) && SCTLR_EL3().IESB == '1'; if IsFeatureImplemented(FEAT_DoubleFault) && EffectiveEA() == '1' && SCR_EL3().NMEA == '1' then sync_errors = TRUE; end; // SCTLR_EL3.IESB might be ignored in Debug state. if !ConstrainUnpredictableBool(Unpredictable_IESBinDebug) then sync_errors = FALSE; end; if sync_errors then SynchronizeErrors(); end; end; UpdateEDSCRFields(); // Update EDSCR PE state flags 2026-03-26 20:27:25 2026-03_rel