Hello
Do Cortex-M85 and Cortex-M55 have core ID ? If the processor is split-lock which is one usable core in lockstep or two usable cores in splitted mode, how can I tell which core it is ?
BR, Grace
Cortex-M55 and Cortex-M85 do not provide a per-core ID register.
The standard CPUID (SCB->CPUID) register identifies the processor type and revision, but it is the same for all instances and does not distinguish between cores.
Lockstep support is selected at RTL configuration time. When lockstep is enabled, the processor behaves architecturally as a single CPU.
There is no split mode where two independent usable cores exist within one processor instance.
Hello Mahmood
Do all the Cortex-M cores have no per-core ID register ? As I find Cortex-M4 also has no core ID register and I'd like to confirm whether it's the common feature for Cortex-M processors ?
Thanks. Grace
Hello Grace,
Yes, that’s correct. Cortex-M processors (including Cortex-M4) do not have a per-core ID register. The CPUID register only identifies the processor type, not the core instance.