EDDEVARCH External Debug Device Architecture Register When FEAT_DoPD is implemented, EDDEVARCH is in the Core power domain. Otherwise, EDDEVARCH is in the Debug power domain Implementation of this register is OPTIONAL. Debug 0xFBC EDDEVARCH When FEAT_DoPD is implemented and !IsCorePowered() ERROR RO Identifies the programmers' model architecture of the external debug component. Identification Registers EDDEVARCH is a 32-bit register. ARCHITECT 31 21 31:21 Defines the architect of the component. For External Debug, this is Arm Limited. Bits [31:28] are the JEP106 continuation code, 0b0100. Bits [27:21] are the JEP106 identification code, 0b0111011. Reads as 0b01000111011. RO PRESENT 20 20 20 DEVARCH present. Indicates that the EDDEVARCH register is present. Reads as 0b1. RO REVISION 19 16 19:16 Defines the architecture revision. For architectures defined by Arm this is the minor revision. For debug, the revision defined by Armv8 is 0x0. All other values are reserved. Reads as 0b0000. RO ARCHVER 15 12 15:12 Architecture Version. Defines the architecture version of the component. EDDEVARCH.ARCHVER and EDDEVARCH.ARCHPART are also defined as a single field, EDDEVARCH.ARCHID, so that EDDEVARCH.ARCHVER is EDDEVARCH.ARCHID[15:12]. FEAT_Debugv8p1 implements the functionality identified by the value 0b0111. FEAT_Debugv8p2 implements the functionality identified by the value 0b1000. FEAT_Debugv8p4 implements the functionality identified by the value 0b1001. FEAT_Debugv8p8 implements the functionality identified by the value 0b1010. FEAT_Debugv8p9 implements the functionality identified by the value 0b1011. From Armv8.1, when FEAT_Debugv8p1 is implemented the value 0b0110 is not permitted. From Armv8.2, the values 0b0110 and 0b0111 are not permitted. From Armv8.4, the value 0b1000 is not permitted. From Armv8.8, the value 0b1001 is not permitted. From Armv8.9, the value 0b1010 is not permitted. 0b0110 Armv8 debug architecture. 0b0111 Armv8.1 debug architecture, FEAT_Debugv8p1. 0b1000 Armv8.2 debug architecture, FEAT_Debugv8p2. 0b1001 Armv8.4 debug architecture, FEAT_Debugv8p4. 0b1010 Armv8.8 debug architecture, FEAT_Debugv8p8. 0b1011 Armv8.9 debug architecture, FEAT_Debugv8p9. RO ARCHPART 11 0 11:0 Architecture Part. Defines the architecture of the component. EDDEVARCH.ARCHVER and EDDEVARCH.ARCHPART are also defined as a single field, EDDEVARCH.ARCHID, so that EDDEVARCH.ARCHPART is EDDEVARCH.ARCHID[11:0]. Armv8-A debug architecture. 0xA15 Armv8-A debug architecture. RO 2026-03-26 20:27:25 2026-03_rel