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SAM4S [DATASHEET]

11100E–ATARM–24-Jul-13

MPU_RBAR

Access: Read-write

Reset: 0x00000000 

Note:

If the region size is 32B, the ADDR field is bits [31:5] and there is no Reserved field.

The MPU_RBAR defines the base address of the MPU region selected by the MPU_RNR, and can update the value of the 
MPU_RNR. 

Write MPU_RBAR with the VALID bit set to 1 to change the current region number and update the MPU_RNR.

The value of N depends on the region size. 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 4 GB, 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 0x00000000.

The base address is aligned to the size of the region. For example, a 64 KB region must be aligned on a multiple of 64 KB, for 
example, at 0x00010000 or 0x00020000.

Write:

0: MPU_RNR not changed, and the processor updates the base address for the region specified in the MPU_RNR, and ignores 
the value of the REGION field.

1: The processor updates the value of the MPU_RNR to the value of the REGION field, and updates the base address for the 
region specified in the REGION field.

Always reads as zero.

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.

31

30

29

28

27

26

25

24

ADDR

23

22

21

20

19

18

17

16

ADDR

15

14

13

12

11

10

9

N

ADDR

N-1

6

5

4

3

2

1

0

–

VALID

REGION