EDDEVAFF0

Copy of the low half of the PE MPIDR_EL1 register that allows a debugger to determine which PE in a multiprocessor system the external debug component relates to.

Configuration

When FEAT_DoPD is implemented, EDDEVAFF0 is in the Core power domain. Otherwise, EDDEVAFF0 is in the Debug power domain.

Attributes

Field descriptions

Bit [31]

U, bit [30]

Indicates a Uniprocessor system, as distinct from PE 0 in a multiprocessor system.

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

U	Meaning
0b0	Processor is part of a multiprocessor system.
0b1	Processor is part of a uniprocessor system.

Access to this field is RO.

Bits [29:25]

MT, bit [24]

Indicates whether the lowest level of affinity consists of logical PEs that are implemented using an interdependent approach, such as multithreading. See the description of Aff0 for more information about affinity levels.

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

MT	Meaning
0b0	Performance of PEs with different affinity level 0 values, and the same values for affinity level 1 and higher, is largely independent.
0b1	Performance of PEs with different affinity level 0 values, and the same values for affinity level 1 and higher, is very interdependent.

Note

This field does not indicate that multithreading is implemented and does not indicate that PEs with different affinity level 0 values, and the same values for affinity level 1 and higher are implemented.

Access to this field is RO.

Aff2, bits [23:16]

Affinity level 2. See the description of Aff0 for more information.

This field has an IMPLEMENTATION DEFINED value.

Access to this field is RO.

Aff1, bits [15:8]

Affinity level 1. See the description of Aff0 for more information.

This field has an IMPLEMENTATION DEFINED value.

Access to this field is RO.

Aff0, bits [7:0]

Affinity level 0. The value of the MPIDR.{Aff2, Aff1, Aff0} or MPIDR_EL1.{Aff3, Aff2, Aff1, Aff0} set of fields of each PE must be unique within the system as a whole.

This field has an IMPLEMENTATION DEFINED value.

Access to this field is RO.

Accessing EDDEVAFF0

EDDEVAFF0 can be accessed through the external debug interface:

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
RAO/WI	U	RES0					MT	Aff2								Aff1								Aff0

EDDEVAFF0, External Debug Device Affinity register 0

Purpose

Configuration

Attributes

Field descriptions

Bit [31]

U, bit [30]

Bits [29:25]

MT, bit [24]

Aff2, bits [23:16]

Aff1, bits [15:8]

Aff0, bits [7:0]

Accessing EDDEVAFF0

EDDEVAFF0 can be accessed through the external debug interface: