EDDEVID External Debug Device ID register 0 When FEAT_DoPD is implemented, EDDEVID is in the Core power domain. Otherwise, EDDEVID is in the Debug power domain Debug 0xFC8 EDDEVID When FEAT_DoPD is implemented and !IsCorePowered() ERROR RO Provides extra information for external debuggers about features of the debug implementation. Identification Registers EDDEVID is a 32-bit register. 31 28 31:28 Reserved, RES0. AuxRegs 27 24 27:24 Indicates support for Auxiliary registers. All other values are reserved. 0b0000 None supported. 0b0001 Support for External Debug Auxiliary Control Register, EDACR. RO 23 8 23:8 Reserved, RES0. DebugPower 7 4 7:4 Indicates support for the FEAT_DoPD feature. FEAT_DoPD implements the functionality added by the value 0b0001. All other values are reserved. 0b0000 FEAT_DoPD not implemented. Registers in the external debug interface register map are implemented in a mix of the Debug and Core power domains. 0b0001 FEAT_DoPD implemented. All registers in the external debug interface register map are implemented in the Core power domain. RO PCSample 3 0 3:0 Indicates the level of PC Sample-based Profiling support using external debug registers. All other values are reserved. When FEAT_PCSRv8p2 is implemented, the only permitted value is 0b0000. FEAT_PCSRv8p2 implements the PC Sample-based Profiling Extension in the Performance Monitors register space, as indicated by the value of PMDEVID.PCSample. 0b0000 PC Sample-based Profiling Extension is not implemented in the external debug registers space. 0b0010 Only EDPCSR and EDCIDSR are implemented. This option is only permitted if EL3 and EL2 are not implemented. 0b0011 EDPCSR, EDCIDSR, and EDVIDSR are implemented. RO 2026-03-26 20:27:25 2026-03_rel