The MPU_RBAR defines the base address of the MPU region selected by the MPU_RNR, and writes to this register can update the value of the MPU_RNR. See the register summary in Table 4.25 for its attributes.
Write MPU_RBAR with the VALID bit set to 1 to change the current region number and update the MPU_RNR. The bit assignments are:
|[31:N]||ADDR||Region base address field. The value of N depends on the region size. For more information, see The ADDR field.|
MPU Region Number valid bit:
0 = MPU_RNR not changed, and the processor:
1 = the processor:
Always reads as zero.
MPU region field.
For the behavior on writes, see the description of the VALID field.
On reads, returns the current region number, as specified by the MPU_RNR.
The ADDR field is bits[31:N] of the MPU_RBAR. The region size, as specified by the SIZE field in the MPU_RASR, defines the value of N:
N = Log2(Region size in bytes),
If the region size is configured to 4GB, in the MPU_RASR,
there is no valid ADDR field. In this case, the region occupies
the complete memory map, and the base address is
The base address must be aligned to the size of the region.
For example, a 64KB region must be aligned on a multiple of 64KB,
for example, at