Atmel SAM4S-EK2 Atmel ATSAM4S-EK2 ATSAM4S-EK2 Ficha De Dados
Códigos do produto
ATSAM4S-EK2
226
SAM4S [DATASHEET]
11100E–ATARM–24-Jul-13
12.11.2.5MPU 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.
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.
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