4.6.3. MPU Region Number Register

The MPU_RNR selects which memory region is referenced by the MPU_RBAR and MPU_RASR registers. See the register summary in Table 4.48 for its attributes. The bit assignments are:

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Table 4.51. MPU_RNR bit assignments

BitsNameFunction
[31:8]-Reserved.
[7:0]REGION

Indicates the MPU region referenced by the MPU_RBAR and MPU_RASR registers.

Depending on your implementation, the MPU supports either 8 or 16 memory regions, so the permitted values of this field are either 0-7 or 0-15.


Normally, you write the required region number to this register before accessing the MPU_RBAR or MPU_RASR. However you can change the region number by writing to the MPU RBAR with the VALID bit set to 1, see MPU Region Base Address Register. This write updates the value of the REGION field.

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