Introduction
ARM DDI 0388I
Copyright © 2008-2012 ARM. All rights reserved.
1-4
ID073015
Non-Confidential
1.2
Cortex-A9 variants
Cortex-A9 processors can be used in both a uniprocessor configuration and multiprocessor
configurations.
In the multiprocessor configuration, up to four Cortex-A9 processors are available in a
cache-coherent cluster, under the control of a
Snoop Control Unit
(SCU), that maintains L1 data
cache coherency.
The Cortex-A9 MPCore multiprocessor has:
•
up to four Cortex-A9 processors
•
an SCU responsible for:
—
maintaining coherency among L1 data caches
—
Accelerator Coherency Port
(ACP) coherency operations
—
routing transactions on Cortex-A9 MPCore AXI master interfaces
—
Cortex-A9 uniprocessor accesses to private memory regions.
•
an
Interrupt Controller
(IC) with support for legacy ARM interrupts
•
a private timer and a private watchdog per processor
•
a global timer
•
AXI high-speed
Advanced Microprocessor Bus Architecture
version 3 (AMBA 3) L2
interfaces.
•
an
Accelerator Coherency Port
(ACP), that is, an optional AXI 64-bit slave port that can
be connected to a DMA engine or a noncached peripheral.
See the
Cortex-A9 MPCore Technical Reference Manual
for more information.
The following system registers have Cortex-A9 MPCore uses:
•
Multiprocessor Affinity Register
•
•
Configuration Base Address Register
.
Some PMU event signals have Cortex-A9 MPCore uses. See