PMDEVAFF0 Performance Monitors Device Affinity register 0 PMU when FEAT_PMUv3_EXT32 is implemented PMU 0xFA8 When FEAT_DoPD is implemented and !IsCorePowered() ERROR RO Copy of the low half of the PE MPIDR_EL1 register that allows a debugger to determine which PE in a multiprocessor system the Performance Monitor component relates to. PMU If FEAT_DoPD is implemented, this register is in the Core power domain. If FEAT_DoPD is not implemented, this register is in the Debug power domain. PMDEVAFF0 is a 32-bit register. 31 31 31 Reserved, RAO/WI. U 30 30 30 Indicates a Uniprocessor system, as distinct from PE 0 in a multiprocessor system. 0b0 Processor is part of a multiprocessor system. 0b1 Processor is part of a uniprocessor system. RO 29 25 29:25 Reserved, RES0. MT 24 24 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. 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. 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. RO Aff2 23 16 23:16 Affinity level 2. See the description of Aff0 for more information. This field has an IMPLEMENTATION DEFINED value. RO Aff1 15 8 15:8 Affinity level 1. See the description of Aff0 for more information. This field has an IMPLEMENTATION DEFINED value. RO Aff0 7 0 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. RO If FEAT_PMUv3_EXT64 is implemented, then the same content is present in the same location, and can be accessed using PMDEVAFF[31:0]. Accessible at offset 0xFA8 from PMU 2026-03-26 20:27:25 2026-03_rel