2.7.4.3 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 2-71 for its attributes. The bit assignments are:

Figure 2-47. SYST_CVR Register Bit Assignments

Table 2-74. MPU_RNR Bit Assignments
Bits	Name	Function
[31:8]		Reserved.
[7:0]	REGION	Indicates the MPU region referenced by the MPU_RBAR and MPU_RASR registers. The MPU supports 8 memory regions, so the permitted values of this field are 0-7.

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 2.7.4.4 MPU Region Base Address Register. This write updates the value of the REGION field.