Signal Descriptions
ARM DDI 0500D
Copyright © 2013-2014 ARM. All rights reserved.
A-17
ID021414
Non-Confidential
A.11
ACE interface signals
This section describes the ACE master interface signals:
•
Clock and configuration signals
.
•
Write address channel signals
on page A-18
.
•
Write data channel signals
on page A-18
.
•
Write data response channel signals
on page A-19
.
•
Read address channel signals
on page A-19
.
•
Read data channel signals
on page A-20
.
•
Coherency address channel signals
on page A-20
.
•
Coherency response channel signals
on page A-20
.
•
Coherency data channel handshake signals
on page A-21
.
•
Read and write acknowledge signals
on page A-21
.
For a complete description of the ACE interface signals, see the
ARM
®
AMBA
®
AXI and ACE
Protocol Specification AXI3, AXI4, and AXI4-Lite, ACE and ACE-Lite
.
Note
•
This interface exists only if the Cortex-A53 processor is configured to have the ACE
interface.
•
All ACE channels must be balanced with respect to
CLKIN
and timed relative to
ACLKENM
.
A.11.1 Clock and configuration signals
Table A-18
shows the clock and configuration signals for the ACE interface.
Table A-18 Clock and configuration signals
Signal
Direction
Description
ACLKENM
Input
ACE Master bus clock enable. See
Clocks
on page 2-9
for more information.
ACINACTM
Input
Snoop interface is inactive and not participating in coherency:
0
Snoop interface is active.
1
Snoop interface is inactive.
SYSBARDISABLE
Input
Disable broadcasting of barriers onto the system bus:
0
Barriers are broadcast onto the system bus. This requires an AMBA4 ACE, or
AMBA5 CHI, interconnect.
1
Barriers are not broadcast onto the system bus. This is compatible with an
AXI3 interconnect and most AMBA4 interconnects.
a
This pin is sampled only during reset of the Cortex-A53 processor.
RDMEMATTR[7:0]
Output
Read request memory attributes.
WRMEMATTR[7:0]
Output
Write request memory attributes.
a. See
Barriers
on page 7-11
.