System Control
ARM DDI 0500D
Copyright © 2013-2014 ARM. All rights reserved.
4-260
ID021414
Non-Confidential
Table 4-233
shows the MAIR0 and MAIR1 bit assignments.
Table 4-234
shows the Attr<n>[7:4] bit assignments.
Table 4-235
shows the Attr<n>[3:0] bit assignments. The encoding of Attr<n>[3:0] depends on
the value of Attr<n>[7:4], as
Table 4-235
shows.
Table 4-233 MAIR0 and MAIR1 bit assignments
Bits
Name
Description
[7:0]
Attr
m
a
The memory attribute encoding for an AttrIndx[2:0] entry in a Long descriptor format translation table entry, where:
•
AttrIndx[2] selects the appropriate MAIR:
—
setting AttrIndx[2] to 0 selects MAIR0.
—
setting AttrIndx[2] to 1 selects MAIR1.
•
AttrIndx[2:0] gives the value of <n> in Attr<n>.
a. Where m is 0-7.
Table 4-234 Attr<n>[7:4] bit assignments
Bits
Meaning
0b0000
Device memory. See
Table 4-235
for the type of Device memory.
0b00RW
, RW not
00
Normal Memory, Outer Write-through transient.
a
a. The transient hint is ignored.
0b0100
Normal Memory, Outer Non-Cacheable.
0b01RW
, RW not
00
Normal Memory, Outer Write-back transient.
a
0b10RW
Normal Memory, Outer Write-through non-transient.
0b11RW
Normal Memory, Outer Write-back non-transient.
Table 4-235 Attr<n>[3:0] bit assignments
Bits
Meaning when Attr<n>[7:4] is 0000
Meaning when Attr<n>[7:4] is not 0000
0b0000
Device-nGnRnE memory
UNPREDICTABLE
0b00RW
, RW not
00
UNPREDICTABLE
Normal Memory, Inner Write-through transient
0b0100
Device-nGnRE memory
Normal memory, Inner Non-Cacheable
0b01RW
, RW not
00
UNPREDICTABLE
Normal Memory, Inner Write-back transient
0b1000
Device-nGRE memory
Normal Memory, Inner Write-through
non-transient (RW=00)
0b10RW
, RW not
00
UNPREDICTABLE
Normal Memory, Inner Write-through non-transient
0b1100
Device-GRE memory
Normal Memory, Inner Write-back non-transient (RW=00)
0b11RW
, RW not
00
UNPREDICTABLE
Normal Memory, Inner Write-back non-transient