EDDEVID, External Debug Device ID register 0

The EDDEVID characteristics are:

Purpose

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

This register is part of the Debug registers functional group.

Usage constraints

This register is accessible as follows:

Default
RO

Configuration

EDDEVID is in the Debug power domain.

Attributes

EDDEVID is a 32-bit register.

Field descriptions

The EDDEVID bit assignments are:

313029282726252423222120191817161514131211109876543210
0000AuxRegs00000000000000000000PCSample

Bits [31:28]

Reserved, RES0.

AuxRegs, bits [27:24]

Indicates support for Auxiliary registers. Permitted values for this field are:

AuxRegsMeaning
0000

None supported.

0001

Support for External Debug Auxiliary Control Register, EDACR.

All other values are reserved.

Bits [23:4]

Reserved, RES0.

PCSample, bits [3:0]

Indicates the level of PC Sample-based Profiling support using external debug registers. Permitted values of this field are:

PCSampleMeaning
0000

Architecture-defined form of PC Sample-based Profiling not implemented using external debug registers.

0010

Only EDPCSR and EDCIDSR are implemented. This option is only permitted if EL3 and EL2 are not implemented.

0011

EDPCSR, EDCIDSR, and EDVIDSR are implemented.

All other values are reserved.

From ARMv8.2 onwards, the only permitted value is 0b0000. The architecture defines the functionality in a different set of registers, see PMDEVID.

Accessing the EDDEVID

EDDEVID can be accessed through the external debug interface:

ComponentOffset
Debug 0xFC8



18/04/2017 17:00

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