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11100B–ATARM–31-Jul-12
SAM4S Series [Preliminary]
11.11.2.5
MPU Region Attribute and Size Register
Name:
MPU_RASR
Access: Read-write
Reset: 0x00000000
The MPU_RASR defines the region size and memory attributes of the MPU region specified by the MPU_RNR, and
enables that region and any subregions.
MPU_RASR is accessible using word or halfword accesses:
• the most significant halfword holds the region attributes.
• the least significant halfword holds the region size, and the region and subregion enable bits.
• XN: Instruction Access Disable
0: Instruction fetches enabled.
1: Instruction fetches disabled.
• AP: Access Permission
See
• TEX, C, B: Memory Access Attributes
See
• S: Shareable
See
• SRD: Subregion Disable
For each bit in this field:
0: corresponding sub-region is enabled.
1: corresponding sub-region is disabled.
See
Region sizes of 128 bytes and less do not support subregions. When writing the attributes for such a region, write the SRD
field as 0x00.
31
30
29
28
27
26
25
24
–
XN
–
AP
23
22
21
20
19
18
17
16
–
TEX
S
C
B
15
14
13
12
11
10
9
8
SRD
7
6
5
4
3
2
1
0
–
SIZE
ENABLE
Summary of Contents for SAM4S Series
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Page 1143: ...1143 11100B ATARM 31 Jul 12 SAM4S Series Preliminary Figure 43 4 64 lead LQFP Package Drawing ...
Page 1145: ...1145 11100B ATARM 31 Jul 12 SAM4S Series Preliminary Figure 43 5 64 lead QFN Package Drawing ...