The MPIDR characteristics are:
whether the processor is part of a Cortex-A9 MPCore implementation.
Cortex-A9 processor accesses within a Cortex-A9 MPCore processor
the target Cortex-A9 processor in a multi-processor cluster system.
- Usage constraints
The MPIDR is:
only accessible in privileged mode.
common to the Secure and Non-secure states.
Available in all configurations. The value of the U bit, bit , indicates if the configuration is a multiprocessor configuration or a uniprocessor configuration.
See the register summary in Table 4.2.
Figure 4.2 shows the MPIDR bit assignments.
Table 4.4 shows the MPIDR bit assignments.
|||-||Indicates the register uses the new multiprocessor format. This is always 1.|
0 = Processor is part of an MPCore cluster.
1 = Processor is a uniprocessor .
Value read in CLUSTERID configuration pins[a]. It identifies a Cortex-A9 MPCore processor in a system with more than one Cortex-A9 MPCore processor present. SBZ for a uniprocessor configuration.
Indicates the CPU number in the Cortex-A9 MPCore configuration:
the uniprocessor version this value is fixed at
[a] A uniprocessor implementation does not include any CLUSTERID pins.
To access the MPIDR, use:
MRC p15,0,<Rd>,c0,c0,5; read Multiprocessor ID register