MPIDR_EL1
64-bitIdentificationMultiprocessor ID: which core in the cluster is running this code. How a scheduler works out which thread it is on, and how an interrupt handler finds the core it belongs to.
Field layout
—
Aff3[39:32]39:32
—
Aff2[23:16]23:16
Aff1[15:8]15:8
Aff0[7:0]7:0
byte 7
byte 6
byte 5
byte 4
byte 3
byte 2
byte 1
byte 0
Current value hover a field to locate it
B7
B6
B5
B4
B3
B2
B1
B0
Fields
| Bits | Field | Bits | Value | Description |
|---|---|---|---|---|
| 63:40 | — | 24 | Not assigned to a documented field. Values written here are reserved and should be treated as read-as-zero unless the architecture says otherwise. | |
| 39:32 | Aff3[39:32] | 8 | 0x0 (0) | Level 3 affinity. Optional, and a single value across the whole system when Aff0 reads zero. |
| 31:24 | — | 8 | Not assigned to a documented field. Values written here are reserved and should be treated as read-as-zero unless the architecture says otherwise. | |
| 23:16 | Aff2[23:16] | 8 | 0x0 (0) | Level 2 affinity, for example the cluster an eight-core block belongs to. |
| 15:8 | Aff1[15:8] | 8 | 0x0 (0) | Level 1 affinity. |
| 7:0 | Aff0[7:0] | 8 | 0x0 (0) | Level 0 affinity, normally the core number within its cluster. |