Editing CPU

[[Category:Hardware]]<noinclude>[[Category:Main]]</noinclude>
== 4 core ARM Cortex-A9 MPCore ==

The ARM Cortex-A9 MPCore is a multicore processor providing up to 4 cache-coherent Cortex-A9 cores, each implementing the ARM v7 instruction set architecture.

=== Specifications ===
* Designed by: ARM
* Common manufacturer(s): TSMC
* CPU clock rate: 111 MHz to 444 MHz (Clockrate can be manually changed if the handheld is modded)
* Instruction set: ARMv7
* Cores: 1-4
* L1 cache: 32 kB I/32 kB D
* L2 cache controller: (0-4 MB)

The actual application processor cores are [http://www.arm.com/products/processors/cortex-a/cortex-a9.php Cortex A9], which is common in modern high performance embedded devices like cell phones and tablets. The [http://infocenter.arm.com/help/topic/com.arm.doc.ddi0388i/index.html Technical Reference Manual] gives a good overview of the specific processor features and is a good reference for what ARMv7 implementation specific features are enabled. The Vita cores have a MIDR value of <code>0x412FC09A</code>, meaning it is Cortex A9 r2p10. Indeed there are usage of undocumented CP15 registers.

Another manual that's important is the [http://infocenter.arm.com/help/topic/com.arm.doc.ddi0407i/index.html MPCore Technical Reference Manual] which is specific to the multi-core system the Vita uses. The main information of use are descriptors for the private memory region defined with the <code>PERIPHBASE</code> signal. This is mapped to [[Physical Memory|physical address]] <code>0x1A000000</code>.

== Interrupt Controller ==
As part of the Cortex A9 MPcore, the Vita also implements the [http://www.systems.ethz.ch/sites/default/files/file/aos2012/ReferenceMaterial/InterruptHandling/GIC_architecture_spec_v1_0.pdf Generic Interrupt Controller Architecture]. More information on interrupts can be found [[Interrupts|here]].

== PL310 L2 Cache ==
The Vita uses the [http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0246a/index.html PL310] L2 cache is is [[Physical Memory|mapped]] to <code>0x1A002000</code>.

=== Debugging/Tracing ===
CoreSight for Cortex-A series processors enable developers to control (debug) and observe (trace) their Cortex-A processor-based SoC with fewer pins. Cortex-A processor debug and run time control can be performed with only 2 pins using the Serial Wire Debug technology or alternatively using JTAG, when highly compressed real-time trace of the cores and others system trace can be captured on-chip (ETB) or exported through a dedicated trace port (TPIU).

== External References ==
* [http://www.arm.com/products/processors/cortex-a/cortex-a9.php ARM Cortex-A9 Processor - main page]
** [http://www.arm.com/files/pdf/ARMCortexA-9Processors.pdf White paper - The ARM Cortex-A9 Processors]
** [http://infocenter.arm.com/help/topic/com.arm.doc.ddi0407e/index.html Cortex-A9 MPCore Technical Reference Manual]
* [http://www.arm.com/products/system-ip/debug-trace/coresight-soc-components/index.php CoreSight - main page]
** [http://www.arm.com/products/system-ip/debug-trace/coresight-soc-components/serial-wire-debug.php CoreSight Debug Access Port : Serial Wire Debug]