Level 2 Memory System
ARM DDI 0500D
Copyright © 2013-2014 ARM. All rights reserved.
7-12
ID021414
Non-Confidential
set the
SYSBARDISABLE
input pin to HIGH on the boundary of the processor. You must also
ensure that the
BROADCASTINNER
,
BROADCASTOUTER
, and
BROADCASTCACHEMAINT
input pins are set to LOW.
7.3.8
AXI privilege information
AXI provides information about the privilege level of an access on the
ARPROTM[0]
and
AWPROTM[0]
signals. However, when accesses might be cached or merged together, the
resulting transaction can have both privileged and unprivileged data combined. If this happens,
the Cortex-A53 processor marks the transaction as privileged, even it if was initiated by an
unprivileged process.
Table 7-10
shows Cortex-A53 processor exception levels and corresponding
ARPROTM[0]
and
AWPROTM[0]
values.
Table 7-10 Cortex-A53 MPCore mode and ARPROT and AWPROT values
Processor exception level
Type of access
Value of
ARPROT
[0]
and
AWPROT[0]
EL0, EL1, EL2, EL3
Cacheable read access
Privileged access
EL0
Device, or normal Non-cacheable read access
Unprivileged access
EL1, EL2, EL3
Privileged access
EL0, EL1, EL2, EL3
Cacheable write access
Privileged access
EL0
Device, nGnRnE, nGnRE, and nGRE write
Unprivileged access
EL1, EL2, EL3
Privileged access
EL0
Normal Non-cacheable or Device GRE write, except for
STREX
,
STREXB
,
STREXH
,
STREXD
,
STXR
,
STXRB
,
STXRH
,
STXP
,
STLXR
,
STLXRB
,
STLXRH
and
STLXP
to shareable memory
Privileged access
EL0
Normal Non-cacheable write for
STREX
,
STREXB
,
STREXH
,
STREXD
,
STXR
STXRB
,
STXRH
,
STXP
,
STLXR
,
STLXRB
,
STLXRH
and
STLXP
to shareable memory
Unprivileged access
EL1, EL2, EL3
Normal Non-cacheable write
Privileged access
EL0, EL1, EL2, EL3
TLB page walk
Privileged access