Atmel SAM4S Xplained Pro Starter and Evaluation Kit ATSAM4S-XPRO ATSAM4S-XPRO Fiche De Données
Codes de produits
ATSAM4S-XPRO
257
SAM4S Series [DATASHEET]
Atmel-11100G-ATARM-SAM4S-Datasheet_27-May-14
12.11.2.9MPU Region Attribute and Size Register Alias 2
Name:
MPU_RASR_A2
Access:
Read
/Write
Reset:
0x00
000000
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:
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.
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 subregion is enabled.
1: Corresponding subregion is disabled.
See
0: Corresponding subregion is enabled.
1: Corresponding subregion is disabled.
See
for more information.
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