EDDEVID | Jon's Arm Reference

Provides extra information for external debuggers about features of the debug implementation.

Configuration

When FEAT_DoPD is implemented, EDDEVID is in the Core power domain. Otherwise, EDDEVID is in the Debug power domain.

Attributes

Field descriptions

Bits [31:28]

AuxRegs, bits [27:24]

Indicates support for Auxiliary registers.

The value of this field is an IMPLEMENTATION DEFINED choice of:

AuxRegs	Meaning
0b0000	None supported.
0b0001	Support for External Debug Auxiliary Control Register, EDACR.

All other values are reserved.

Access to this field is RO.

Bits [23:8]

DebugPower, bits [7:4]

Indicates support for the FEAT_DoPD feature.

The value of this field is an IMPLEMENTATION DEFINED choice of:

DebugPower	Meaning
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.

FEAT_DoPD implements the functionality added by the value 0b0001.

All other values are reserved.

Access to this field is RO.

PCSample, bits [3:0]

Indicates the level of PC Sample-based Profiling support using external debug registers.

The value of this field is an IMPLEMENTATION DEFINED choice of:

PCSample	Meaning
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.

All other values are reserved.

When FEAT_PCSRv8p2 is implemented, the only permitted value is 0b0000.

Note

FEAT_PCSRv8p2 implements the PC Sample-based Profiling Extension in the Performance Monitors register space, as indicated by the value of PMU.PMDEVID.PCSample.

Access to this field is RO.

31	30	29	28	27	26	25	24	23	22	21	20	19	18	17	16	15	14	13	12	11	10	9	8	7	6	5	4	3	2	1	0
RES0				AuxRegs				RES0																DebugPower				PCSample

EDDEVID: External Debug Device ID register 0

Purpose

Configuration

Attributes

Field descriptions

Bits [31:28]

AuxRegs, bits [27:24]

Bits [23:8]

DebugPower, bits [7:4]

PCSample, bits [3:0]

Accessing EDDEVID

EDDEVID can be accessed through the external debug interface: