Datasheet

SAM4E [DATASHEET]
Atmel-11157D-ATARM-SAM4E16-SAM4E8-Datasheet_12-Jun-14
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12.11.2.5 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 Table 12-39.
 TEX, C, B: Memory Access Attributes
See Table 12-37.
 S: Shareable
See Table 12-37.
 SRD: Subregion Disable
For each bit in this field:
0: Corresponding subregion is enabled.
1: Corresponding subregion is disabled.
See “Subregions” 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
–TEXSCB
15 14 13 12 11 10 9 8
SRD
76543210
–SIZEENABLE