Level 1 Memory System
ARM DDI 0500D
Copyright © 2013-2014 ARM. All rights reserved.
6-10
ID021414
Non-Confidential
6.5.2
ACE transactions
Table 6-2
shows the ACE transactions that each type of memory access generates.
See the
ARM
®
AMBA
®
AXI and ACE Protocol Specification AXI3, AXI4, and AXI4-Lite, ACE
and ACE-Lite
for more information about ACE transactions.
Table 6-2 ACE transactions
Attributes
ACE transaction
Memory type
Shareability
Domain
Load
Store
Load
exclusive
Store
exclusive
Device
-
System
ReadNoSnoop
WriteNoSnoop
ReadNoSnoop
and
ARLOCKM
set to HIGH
WriteNoSnoop
and
AWLOCKM
set to HIGH
Normal, inner
Non-cacheable, outer
Non-cacheable
Non-shared System
ReadNoSnoop
WriteNoSnoop
ReadNoSnoop
and
ARLOCKM
set to HIGH
WriteNoSnoop
and
AWLOCKM
set to HIGH
Inner-shared
Outer-shared
Normal, inner
Non-cacheable, outer
Write-Back or
Write-Through, or
Normal, inner
Write-Through, outer
Write-Back,
Write-Through or
Non-cacheable, or
Normal inner
Write-Back outer
Non-cacheable or
Write-Through
Non-shared System
ReadNoSnoop
WriteNoSnoop
ReadNoSnoop ReadNoSnoop
Inner-shared
System
ReadNoSnoop
WriteNoSnoop
ReadNoSnoop
with
ARLOCKM
set to HIGH
WriteNoSnoop
with
ARLOCKM
set to HIGH
Outer-shared
System
Normal, inner
Write-Back, outer
Write-Back
Non-shared Non-shareable
ReadNoSnoop
WriteNoSnoop
ReadNoSnoop WriteNoSnoop
Inner-shared
Inner Shareable
ReadShared
ReadUnique or
CleanUnique if
required, then a
WriteBack
when the line is
evicted
ReadShared
with
ARLOCKM
set to HIGH
CleanUnique
with
ARLOCKM
set to HIGH if
required, then a
WriteBack
when the line is
evicted
Outer-shared
Outer Shareable