53
32000D–04/2011
AVR32
V - Valid. Set if the protection region is valid, cleared otherwise. This bit is written to 0 by a
reset. The region is not considered in the protection testing if the V bit is cleared.
6.2.1.2
MPU Permission Select Register - MPUPSRn
A MPU Permission Select register is implemented for each of the 8 protection regions. Each
MPUPSR register divides the protection region into 16 subregions. The bitfields in MPUPSR
specifies whether each subregion has access permissions as specified by the region entry in
either MPUAPRA or MPUAPRB.
Table 6-1.
Protection region sizes implied by the Size field
Size
Region size
Constraints on Base address
B’00000 to B’01010
UNDEFINED
-
B’01011
4 KB
None
B’01100
8 KB
Bit [12] in Size must be 0
B’01101
16 KB
Bit [13:12] in Size must be 0
B’01110
32 KB
Bit [14:12] in Size must be 0
B’01111
64 KB
Bit [15:12] in Size must be 0
B’10000
128 KB
Bit [16:12] in Size must be 0
B’10001
256 KB
Bit [17:12] in Size must be 0
B’10010
512 KB
Bit [18:12] in Size must be 0
B’10011
1 Mb
Bit [19:12] in Size must be 0
B’10100
2 MB
Bit [20:12] in Size must be 0
B’10101
4 MB
Bit [21:12] in Size must be 0
B’10110
8 MB
Bit [22:12] in Size must be 0
B’10111
16 MB
Bit [23:12] in Size must be 0
B’11000
32 MB
Bit [24:12] in Size must be 0
B’11001
64 MB
Bit [25:12] in Size must be 0
B’11010
128 MB
Bit [26:12] in Size must be 0
B’11011
256 MB
Bit [27:12] in Size must be 0
B’11100
512 MB
Bit [28:12] in Size must be 0
B’11101
1 GB
Bit [29:12] in Size must be 0
B’11110
2 GB
Bit [30:12] in Size must be 0
B’11111
4 GB
Bit [31:12] in Size must be 0
Table 6-2.
Subregion access permission implied by MPUPSR bitfields
MPUPSRn[P]
Access permission
0
MPUAPRA[APn]
1
MPUAPRB[APn]