B2.84
Multiprocessor Affinity Register, EL1
The MPIDR_EL1 characteristics are:
Purpose
Provides an additional core identification mechanism for scheduling purposes in a cluster
system.
Usage constraints
This register is accessible as follows:
EL0 EL1
(NS)
EL1
(S)
EL2 EL3
(SCR.NS = 1)
EL3
(SCR.NS = 0)
-
RO
RO
RO
RO
RO
Configurations
MPIDR_EL1[31:0] is:
• Architecturally mapped to AArch32 register MPIDR. See
.
• Mapped to external register EDDEVAFF0.
MPIDR_EL1[63:32] is:
• Mapped to external register EDDEVAFF1.
Attributes
MPIDR_EL1 is a 64-bit register.
Aff1
Aff0
0
63
16 15
8 7
Aff2
23
24
MT
RES
0
29
30
U
32 31
Aff3
40 39
RES
0
RES
1
25
Figure B2-54 MPIDR_EL1 bit assignments
[63:40]
Reserved,
RES0
.
Aff3, [39:32]
Affinity level 3. Highest level affinity field.
Reserved,
RES0
.
[31]
Reserved,
RES1
.
U, [30]
Indicates a single core system, as distinct from core 0 in a cluster. This value is:
0
Processor is part of a multiprocessor system. This is the value for implementations
with more than one core, and for implementations with an ACE or CHI master
interface.
1
Processor is part of a uniprocessor system. This is the value for single core
implementations with an AXI master interface.
B2 AArch64 system registers
B2.84 Multiprocessor Affinity Register, EL1
100236_0100_00_en
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B2-512
Non-Confidential
Summary of Contents for Cortex-A35
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