LOCK

nRF54LM20A | nRF54LM20B Datasheet

Address offset: 0x500

Register to lock the certain parts of the CPU from being modified.

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.