Ken Shirriff has an interesting article on reverse engineering the original ARM1 processor (as designed by ARM, and implemented by VLSI). He goes right to the silicon to form a transistor level model/emulator of the chip. Back in 1986 when the ARM was designed and released, it wasn’t very well known, being used in very few devices. This continued for over a decade surprisingly. being used in niche markets (the Apple Newton, the DEC StrongARM on RAID cards, etc). It wasn’t until the 2000’s that this processor startup from England became the powerhouse it is today. Two major developments drove this, mobile, and multimedia. The ARM architecture was powerful, small, and easy on the power budget, this obviously was a benefit for mobile, but also proved very useful in dealing with multimedia processing, such as controllers on DVD players, digital picture frames, MP3 players and the like. Today, hundreds of companies license and use the architecture and it is found in devices now numbering in the billions.
It’s well known that Intel missed the jump on tablet and phone processors. Intel sold off their PXA line of ARM processors to Marvell in 2006, in an attempt to ‘get back to the basics.’ It turned out that this sale perhaps was a bit premature, as the basics ended up being mobile, and mobile is where Intel struggled (by mobile we mean phones/tablets, not laptops, which Intel has no problems with).
In January of 2011 Intel purchased the communications division of Infineon, gaining a line of application and baseband processors, based on ARM architecture of course. Intel developed this into the SoFIA applications processor, which was ironically fab’d by TSMC. Eventually the designs would be ported to Intel 14nm process, or that was the plan.
So this weeks announcement that Intel has signed an agreement with the Chinese company Rockchip, to cooperate on mobile applications processors is a bit of a surprise, but the details show that it makes sense. Rockchips current offerings are ARM based, much as Intel’s current SoFIA processor, as well as Apple Ax series, Qualcomm’s SnapDragon, TI’s OMAP, etc. However, the agreement with Rockchip is not about ARM, its about x86. For the first time in many years Intel has granted another company an x86 license, specifically, Intel will help ROckchip build a quad-core Atom based x86 processor with integrated 3G modem. Rockchip currently uses TSMC as their fab, however also with this agreement Rockchip gets access to Intel 22nm and 14nm fab capacity.
We recently received several Remote Server management cards, powered by the Agilent (spun off of HP in 1999) N2530 SoC. This SoC provides the processing for remotely administering, and managing servers. At its hearts is an ARM processor running at 33MHz. Proudly marked on the chip, is ‘ARM 701 POWERED.’ There is one problem, there never was an ARM701 processor core. The N2530 is in fact powered by an ARM710. A typo was made when marked the Rev D chips, and later fixed on the Revision E. I have not yet received an example of a Rev C (or earlier) to see if they too have this error, but E and later certainly did not. The Agilent N2530 was used for many years in the early 2000’s on cards by Dell, Fujitsu, and IBM (and likely others). Essentially forming a computer within a computer, these cards often had their own graphics support (ATI Mobility Radeon, among others) as well as support for CD-ROMs, hard drives, LAN (for access) and everything else you would find in a stand alone computer. Typically they could remote start, reboot, and power down servers, all over a network connection.
Bloomberg Business Week recently published an interesting article on ARM’s rise to power in the processing world. There first major design ‘win’ was a failed product known as the Apple Newton, yet they would go on to become a powerhouse that is no challenging Intel.
In ARM’s formative years, the 1990’s, the most popular RISC processor was the MIPS architecture, which powered high end computers by SGI, while Intel made super computers (the Paragon) based on another RISC design, the i860. Now, nearly 2 decades later, after Intel abandoned their foray into the ARM architecture (StrongARM and X-Scale) RISC is again challenging Intel in the server market, this time, led by ARM.
MIPS, now owned by Imagination, is again turning out new IP cores to compete with ARM, and other embedded cores. Their Warrior class processors are already providing 64-bit embedded processing power, though with a lot less press that the likes of Apple’s A7.
‘Itanium is dead’ is a phrase that has been used for over a decade, in fact many claimed that the Itanium experiment was dead before it even launched in 2001. The last hold-out of the Itanium architecture was HP, likely because the Itanium had a lot in common with its own PA-RISC. However HP has announced that they will be transitioning their NonStop sever series to x86, presumably the new 15-core Xeons Intel is developing. Itanium was launched with goal of storming the server market, billed as the next greatest thing, it failed to make the inroads expected, largely due to the 2 decades of x86 code it didnt support, and poor initial compiler support. Many things were learned from Itanium so though it will become but a footnote, its technology will live on.
Interestingly other architectures that seemed to be n the brink are getting continued support in new chips. Imagination, known for their graphics IP, purchased MIPS, and now has announced the MIPS Warrior P-class core. This core supports speeds of over 2GHz, and is the first MIPS core with 128 bit SIMD support.
Broadcom, historically a MIPS powerhouse, has announced a 64-bit ARM server class processor with speeds of up to 3GHz. Perhaps ironic that ARM is now being introduced into a market that Itanium was designed for. Broadcom has an ARM Architecture license, meaning they can roll their own designs that implement the ARM instruction set, similar to Qualcomm and several others.
POWER continues to show its remarkable flexibility. Used by IBM in larger mainframes in the POWER7 and POWER8 implementations it crunches data at speeds up to 4.4GHz. On the other end of the spectrum, Freescale (formerly Motorola, one of the developers of the POWER architecture) has announced the 1.8GHz quad-core QorIQ T2080 for control applications such as networking, and other embedded use. These days the POWER architecture is not often talked about, at least in the embedded market, but it continues to soldier on and be widely used. LSI has used it in their Fusion-MPT RAID controllers, Xilinx continues to offer it embedded in FPGAs and BAE continues to offer it in the form of the RAD750 for space-based applications.
Perhaps it is this flexibility of use that has continued to allow architectures to be used. Itanium was very focused, and did its one job very well. Same goes for the Alpha architecture, and the Intel i860, all of which are now discontinued. ARM, MIPS, POWER, x86 and a host of MCU architectures continue to be used because of their flexibility and large code bases.
So what architecture will be next to fall? And will a truly new architecture be introduced that has the power and flexibility to stick around?
China is generally seen as where devices are made or assembled, rather then where they are designed or invented, certainly in the computer world. In 2001 a Chinese Gov’t funded venture known as ARCA Technologies changed that. ARCA (Advanced RISC Computer Architecture) designed and released a completely new processor known as the Arca-1. At the time there were two design houses working to create China’s first CPU. Arca, and BLX. BLX made the Godson series of processors which are MIPS32 and MIPS64 implementations. Arca, took a different approach. Not only did they seek to make an indigenous design, but they wanted to do so with their own Instruction Set Architecture (ISA).
The ArcaISA is, of course, RISC based, it contains 80 instructions, with each instruction consisting of up to 3 operands, and contains 32 general purpose registers. The original Arca-1 design is made on a 0.25 micron process (by which foundry is unclear, BLX used ST) with a 5-stage pipeline and drawing 1.2W at a clock speed of 166MHz. It contained separate 32 way associative 8K caches for Instruction and Data. The Arca also includes a DSP unit that has a pair of multiply/Accumulate Units (MACs) as well as basic SIMD support for media acceleration (including hardware MPEG2). Not exactly impressive for 2001, but not bad for a first release. However there was more to come.
The introduction of the iPhone 5 was also the introduction of Apple’s first truly original Application Processor design. The iPhone 2, 3G and 3GS all featured designs by Samsung. The iPhone 4 introduced the A4, which was closely based on the Hummingbird Cortex-A8 core developed with Samsung and Intrinsity, again, not a truly Apple design. The iPhone 4S introduced the A5 (and the A5X used in the iPad 2). The A5 is based on the ARM Cortex-A9 MPCore, a standard ARM design, albeit with many added features, but architecturally, the processor is not original, just customized.
ARM provides cores designs for use by developers, such as the Cortex-A9, A8, etc. These are complete designs of processors that you can drop into your system design as a block, add your own functions, such as a graphics system, audio processing, image handling, radio control, etc and you have your processor. This is the way many processor vendors go about things. They do not have to spend the time and effort to design a processor core, just pick one that meets their needs (power budget, speed, die area) and add any peripherals Many of these peripherals are also licensed as Intellectual Property (IP) blocks making building a processor in some ways similar to construction with Legos. This is not to say that this is easy, or the wrong way to go about things, it is in fact the only way to get a design to market in a matter of weeks, rather then years. It allows for a wide product portfolio that can meet many customers needs. The blocks are often offered for a specific process, so not only can you purchase a license to a Cortex-A9 MPCore, you can purchase one that is hardware ready for a TSMC 32nm High-k Metal Gate process, or a 28nm Global Foundries process. This greatly reduces the amount of work needed to make a design work with a chosen process. This is what ARM calls the Processor Foundry Program.
Back in 2010 we did a write up on the many processors in each iPhone for each version through the iPhone 4. Since then Apple has released the iPhone 4 (CDMA) and the mid-cycle refresh iPhone 4S. Seeing as the iPhone 5 should be released on September 12th here is a quick update to bring our table up to date.
CPUs by function and generation of iPhone:
|App Processor||Samsung S3C6400 400-412MHz ARM1176JZ||Samsung S3C6400 400-412MHz ARM1176JZ||Samsung S5PC100 600MHZ ARM Cortex A8||Apple A4 800MHz ARM Cortex A8||Apple A4 800MHz ARM Cortex A8||Apple A5 900Mhz Dual core ARM Cortex-A9|
|Baseband||S-GOLD2 ARM926EJ-S <200MHz||Infineon X-Gold 608 ARM926 312MHz + ARM7TDMI-S||Infineon X-Gold 608 ARM926 312MHz + ARM7TDMI-S||X-Gold 618 ARM1176 416MHz||Qualcomm MDM6600 ARM1136JS 512MHz||Qualcomm MDM6610 ARM1136JS 512MHz|
|GPS||NA||Infineon HammerHead II||Infineon HammerHead II||BCM4750 (no CPU core)||see above||see above|
|Bluetooth||BlueCore XA-RISC||BlueCore XA-RISC||BCM4325 (2 CPU cores)||BCM4329 (2 CPU cores)||BCM4329 (2 CPU Cores)||BCM4330ARM Cortex-M3 + Bluetooth CPU|
|Wifi||Marvell 88W8686 Feroceon ARMv5 128MHz||Marvell 88W8686 Feroceon ARMv5 128MHz||see above||see above||see above||see above|
|OS||Nucleus by Mentor Graphics||Nucleus||Nucleus||ThreadX by ExpressLogic||REX by Qualcomm||REX by Qualcomm|
Apple iPhone 4 CDMA
The CDMA version of the iPhone 4 switched from an Infineon X-Gold baseband to a Qualcomm MDM6600 running a 512MHz ARM1136JS core. Interestingly this baseband supports GSM but due to antenna issues it is not implemented here. The Qualcomm Gobi, as it is known, also has integrated GPS, removing the need for the old Broadcom BCM4750. This sets the stage for the iPhone 4S.
Now the UBM Techinsights and iFixIt have completed their teardowns of the iPad 2, and benchmarks have been run we now know that the A5 is in fact a dual core, made by Samsung, and clocked at around 900MHz. It also includes the PowerVR 543 dual core GPU as we suspected in our previous post.
Also we now have an actual image of the chip, rather then the photoshopped one Apple used in their presentation.
Today Apple announced the iPad 2, which unless you are living in a cave, you likely have heard about more then you wish already. The iPad 2 debuts the next evolution in Apples own ARM processor. The A4 (which was a single core 1GHz class ARM Cortex-A8 made by Samsung) is out, and a dual core replacement is in. Details are thin until a proper tear down is done, but it is most likely a 1GHz dual core ARM Cortex-A9 with a dual core PowerVR 543 replacing the single core PowerVR 535. It is most likely fab’d again by Samsung. Apple’s press shot during their presentation is NOT an A5, the PR folks at Apple simply Photoshopped the original press shot of the A4 from last year. Note the date codes on the chip are 0939 and 0940 (sine their is 2 dies in it), which is late 2009.
Apple also made the somewhat deceptive remark that the iPad 2 is the first dual core tablet to ship ‘in volume.’ HP’s Touchpad runs a dual core Snapdragon and is shipping ‘soon.’ LG is shipping their tablet this month with a very capable Tegra 2, and Samsung will follow with the Galaxy Tab 10.1, also Tegra 2 powered. RIM’s Playbook which is in beta, used a TI OMAP 4430 dual core Cortex-A9. This puts Apple right in the mix of the dual core frenzy that will playout this year.
We’ll update the photo as soon as someone (likely the folks at iFixIt) get and tear one down.