System Control
ARM DDI 0500D
Copyright © 2013-2014 ARM. All rights reserved.
4-257
ID021414
Non-Confidential
Table 4-231
shows the PRRR bit assignments.
Table 4-231 PRRR bit assignments
Bits
Name Function
[24+
n
]
a
NOS
n
Outer Shareable property mapping for memory attributes
n
, if the region is mapped as Normal Shareable.
n
is the value of the TEX[0], C and B bits concatenated. The possible values of each NOS
n
bit are:
0
Memory region is Outer Shareable.
1
Memory region is Inner Shareable.
The value of this bit is ignored if the region is Normal or Device memory that is not Shareable.
[23:20]
-
Reserved,
RES
0.
[19]
NS1
Mapping of S = 1 attribute for Normal memory. This bit gives the mapped Shareable attribute for a region of
memory that:
•
Is mapped as Normal memory.
•
Has the S bit set to 1.
The possible values of the bit are:
0
Region is not Shareable.
1
Region is Shareable.
[18]
NS0
Mapping of S = 0 attribute for Normal memory. This bit gives the mapped Shareable attribute for a region of
memory that:
•
Is mapped as Normal memory.
•
Has the S bit set to 0.
The possible values of the bit are the same as those given for the NS1 bit, bit[19].
[17]
DS1
Mapping of S = 1 attribute for Device memory. This bit gives the mapped Shareable attribute for a region of
memory that:
•
Is mapped as Device memory.
•
Has the S bit set to 1.
Note
This field has no significance in the processor.
[16]
DS0
Mapping of S = 0 attribute for Device memory. This bit gives the mapped Shareable attribute for a region of
memory that:
•
Is mapped as Device memory.
•
Has the S bit set to 0.
Note
This field has no significance in the processor.
[2
n
+1:2
n
]
a
TR
n
Primary TEX mapping for memory attributes
n
.
n
is the value of the TEX[0], C and B bits, see
Table 4-232
on page 4-258
. This field defines the mapped memory type for a region with attributes
n
. The possible values
of the field are:
0b00
Device (nGnRnE).
0b01
Device (not nGnRnE).
0b10
Normal Memory.
0b11
Reserved, effect is
UNPREDICTABLE
.
a. Where n is 0-7.