EDDEVARCH, External Debug Device Architecture Register

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.

Access to this field is RO.

DEVARCH present. Indicates that the EDDEVARCH register is present.

Reads as 0b1.

Access to this field is RO.

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.

Access to this field is RO.

Architecture Version. Defines the architecture version of the component. Defined values are:

ARCHVER	Meaning
0b0110	Armv8 debug architecture.
0b0111	Armv8 debug architecture with Virtualization Host Extensions.
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.

EDDEVARCH.ARCHVER and EDDEVARCH.ARCHPART are also defined as a single field, EDDEVARCH.ARCHID, so that EDDEVARCH.ARCHVER is EDDEVARCH.ARCHID[15:12].

FEAT_VHE 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_VHE 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.

Architecture Part. Defines the architecture of the component.

ARCHPART	Meaning
0xA15	Armv8-A debug architecture.

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.

Access to this field is RO.