CPUC — CPU control

CPUC controls elements of the Arm® Cortex®-M33 processor such as lock certain features of the CPU and prevent them from being modified.

CPUC holds a CPU identifier CPUID, used in the system to uniquely identify the processing unit of a core.

In addition, CPUC holds a LOCK register, which is used to lock certain CPU features and prevent them from being modified. One example is the LOCK.LOCKSAU field. When set to Locked, this prevents further modifications to the SAU registers.

Registers

Instances


Instance	Domain	Base address	Description
CPUC	APPLICATION	0xE0080000	Cortex-M33 configuration

Register overview


Register	Offset	Description
LOCK	0x500	Register to lock the certain parts of the CPU from being modified.
CPUID	0x504	The identifier for the CPU in this subsystem.

LOCK

Address offset: 0x500

Each bit can only be written once and can only be changed from 0 to 1.


Bit number				31	30	29	28	27	26	25	24	23	22	21	20	19	18	17	16	15	14	13	12	11	10	9	8	7	6	5	4	3	2	1	0
ID																															E	D	C	B	A
Reset 0x00000000				0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
ID	R/W	Field	Value ID	Value								Description
A	RW	LOCKVTORAIRCRS										Locks both the Vector table Offset Register (VTOR) and Application Interrupt and Reset Control Register (AIRCR) for secure mode.
			NotLocked	0								Both VTOR and AIRCR can be changed.
			Locked	1								Prevents changes to both VTOR and AIRCR.
B	RW	LOCKVTORNS										Locks the Vector table Offset Register (VTOR) for non-secure mode.
			NotLocked	0								VTOR can be changed.
			Locked	1								Prevents changes to VTOR.
C	RW	LOCKMPUS										Locks the Memory Protection Unit (MPU) for secure mode.
			NotLocked	0								MPU registers can be changed.
			Locked	1								Prevents changes to MPU registers.
D	RW	LOCKMPUNS										Locks the Memory Protection Unit (MPU) for non secure mode.
			NotLocked	0								MPU registers can be changed.
			Locked	1								Prevents changes to MPU registers.
E	RW	LOCKSAU										Locks the Security Attribution Unit (SAU)
			NotLocked	0								SAU registers can be changed.
			Locked	1								Prevents changes to SAU registers.

CPUID

Address offset: 0x504

The identifier for the CPU in this subsystem.


Bit number				31	30	29	28	27	26	25	24	23	22	21	20	19	18	17	16	15	14	13	12	11	10	9	8	7	6	5	4	3	2	1	0
ID				A	A	A	A	A	A	A	A	A	A	A	A	A	A	A	A	A	A	A	A	A	A	A	A	A	A	A	A	A	A	A	A
Reset 0x00000000				0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
ID	R/W	Field	Value ID	Value								Description
A	R	CPUID										The CPU identifier.