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	<title>Julian Rex &#187; arm</title>
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	<description>iPhone and iPad Apps and Game Development</description>
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		<title>iPhone 3GS, Cortex A8 and the PowerVR SGX</title>
		<link>http://julianrex.com/2009/06/iphone-3gs-cortex-a8-and-the-powervr-sgx/</link>
		<comments>http://julianrex.com/2009/06/iphone-3gs-cortex-a8-and-the-powervr-sgx/#comments</comments>
		<pubDate>Wed, 10 Jun 2009 19:35:45 +0000</pubDate>
		<dc:creator>Julian</dc:creator>
				<category><![CDATA[Uncategorized]]></category>
		<category><![CDATA[arm]]></category>
		<category><![CDATA[Cortex A8]]></category>
		<category><![CDATA[iOS]]></category>
		<category><![CDATA[NEON]]></category>
		<category><![CDATA[PowerVR]]></category>

		<guid isPermaLink="false">http://rexy.co.uk/?p=88</guid>
		<description><![CDATA[Just a quick note about the new iPhone 3GS. Recently Noel Llopis tweeted about an AnandTech article, which contains more detailed info about the iPhone 3GS and its hardware (see page 2 for the juicy details). It&#8217;s not clear if the information comes from a tear-down, but it matches a lot of other information out [...]]]></description>
			<content:encoded><![CDATA[<p>Just a quick note about the new iPhone 3GS. Recently <a href="http://www.snappytouch.com/">Noel Llopis</a> <a href="http://twitter.com/snappytouch/statuses/2105936384">tweeted</a> about an <a href="http://www.anandtech.com/gadgets/showdoc.aspx?i=3579&#038;p=1">AnandTech article</a>, which contains more detailed info about the iPhone 3GS and its hardware  (see page 2 for the juicy details).</p>
<p>It&#8217;s not clear if the information comes from a tear-down, but it matches a lot of other information out there in the wild. So while this hasn&#8217;t been confirmed, I&#8217;m happy to assume that the info is good. </p>
<p>The Cortex A8 is an ARMv7 chip, where the chip in the existing iPhones is an ARMv6. The PowerVR MBX, gets replaced by a PowerVR SGX with programmable shaders. </p>
<p>These specs represent a big leap in performance <a href="http://rexy.co.uk/2008/10/iphone-arm-references/">compared with the previous generations</a>; NEON represents improvements for SIMD operations, in terms of speed and usage, and OpenGLES 2.0 will give improved graphical performance and fidelity: Sony needs to come up with a PSP2 soon, as this new iPhone has some serious oomph.</p>
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		<title>iPhone ARM references</title>
		<link>http://julianrex.com/2008/10/iphone-arm-references/</link>
		<comments>http://julianrex.com/2008/10/iphone-arm-references/#comments</comments>
		<pubDate>Tue, 28 Oct 2008 14:44:11 +0000</pubDate>
		<dc:creator>Julian</dc:creator>
				<category><![CDATA[Uncategorized]]></category>
		<category><![CDATA[arm]]></category>
		<category><![CDATA[iOS]]></category>
		<category><![CDATA[vfp]]></category>

		<guid isPermaLink="false">http://rexy.co.uk/wordpress/?p=8</guid>
		<description><![CDATA[June 2009: The recently announced iPhone 3GS has a different set of hardware, and the original post does not apply to this new device. The chip is suspected to be the ARM Cortex-A8, based on ARMv7 (compare with ARMv6 below). Looking at the specs it appears to have a NEON unit, which should be good [...]]]></description>
			<content:encoded><![CDATA[<p class="updated">June 2009: The recently announced iPhone 3GS has a different set of hardware, and the original post does not apply to this new device. The chip is suspected to be the ARM Cortex-A8, based on ARMv7 (compare with ARMv6 below). <a href="http://www.arm.com/products/CPUs/ARM_Cortex-A8.html">Looking at the specs</a> it appears to have a NEON unit, which should be good news for games developers.</p>
<p>Well over a year ago Engadget <a href="http://www.engadget.com/2007/07/01/iphone-processor-found-620mhz-arm/">posted a description</a> of the (suspected) processor in the iPhone  - <a href="http://www.arm.com/products/CPUs/ARM1176.html">ARM1176JZF</a> (ARM11 family, implementing the ARMv6 instruction set). It has a VFP11 vector coprocessor for SIMD operations. It <a href="http://www.arm.com/products/CPUs/architecture.html">does not support NEON</a> as some have suggested.</p>
<p style="text-align: center;">
<a href="http://www.arm.com/products/CPUs/ARM1176.html"><img class="aligncenter" src="/images/4038.jpg" alt="" width="200" height="239" /></a>
</p>
<p>In my attempt to figure out how to access the SIMD operations for matrix and vector math, I&#8217;ve found these reference PDFs that might be of use to others:</p>
<ul>
<li>The <a href="http://www.arm.com/miscPDFs/14128.pdf">ARM Architecture Reference Manual</a></li>
<li>The <a href="http://infocenter.arm.com/help/topic/com.arm.doc.ddi0301g/DDI0301G_arm1176jzfs_r0p7_trm.pdf">ARM1176JZF-S Technical Reference Manual</a></li>
<li>The <a href="http://infocenter.arm.com/help/topic/com.arm.doc.qrc0007d/QRC0007_VFP.pdf">Vector Floating Point Instruction Set Quick Reference Card</a></li>
</ul>
<p>There&#8217;s also a (pay-for) article on the IEEE Xplore website, called <a href="http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=1291935">&#8220;Accelerating floating-point 3D graphics for vector microprocessors&#8221;</a>, which talks specifically about ARM VFP processors.</p>
<p>It may also be worth keeping an eye on <a href="http://code.google.com/p/vfpmathlibrary/">this math library</a>, which forms part of the <a href="http://oolongengine.com/">Oolong Engine</a>.</p>
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