ARM Unveils One-chip SMP Multiprocessor Core 145
An anonymous reader writes "ARM Ltd. will unveil a unique multi-processor core technology, capable of up to 4-way cache coherent symmetric multi-processing (SMP) running Linux, this week at the Embedded Processor Forum in San Jose, Calif.. The "synthesizable multiprocessor" core -- a first for ARM -- is the result of a partnership with NEC Electronics announced last October, and is based on ARM's ARMv6 architecture.
ARM says its new "MPCore" multiprocessor core can be configured to contain between one and four processors delivering up to 2600 Dhrystone MIPS of aggregate performance, based on clock rates between 335 and 550 MHz."
ARM servers (Score:5, Interesting)
Looks like here we are pointing at server technology.
How long before we have a 64/32/16 bit vatiable word size Thumb like architecture?
ARM servers (Score:5, Interesting)
Re:ARM servers (Score:3, Insightful)
I was an Acorn Archimedes user for more than 10 years (the workstation that the ARM was originally designed for) and they were great systems. Affordable, decent speed and good operating system.
Alas, they were not "PC-compatible" and at a certain time the Intel/AMD clones with Linux became much more attractive.
Re:ARM servers (Score:2, Informative)
Not that they wouldn't have worked just fine with ARM, but as far as I can tell the idea never even came up.
Re:ARM servers (Score:4, Informative)
ARM has been used in many PDAs as you say, and in Acorn/Archimedes computers. It's also in the Game Boy Advance (ARM7 I believe) and will likely be the foundation of the Dual Screen (ARM9 and ARM7 both will be in the box, if leaked specs can be believed.) Arm also begat StrongARM, and intel purchased (some level of) rights to the StrongARM II architecture, which they call XScale.
Re:ARM servers (Score:2)
If you need evidence, then consider the issues of time to wake from idle and average power consumption in idle. StrongARM did a fantastic job of managing them, given the clock speeds at which it ran. The earlier XScale chips...well, they just did not. Bulverde (gen 3 XScale) is finally starting to get a handle on those problems. XScale was designed to scale to high clock speeds, but not to handl
Re:ARM servers (Score:2, Informative)
In a court case between DEC & Intel which was settled, DEC sold it's fabs (I think they had one or two left)
Oops! (Score:2)
Yep! MIPS... But, Acorn, Now those are pretty nifty also.
Re:ARM servers (Score:2)
Re:ARM servers (Score:2)
You are probably thinking about the NetWinder.
Re:ARM servers (Score:2)
Aside from the fact that Cobalts were actually based on MIPS parts, as several other posters have noted...
The generally accepted reason for the failure of ARM to move up-scale so far is that the main company producing high-end ARMs these days has been Intel. Oddly, they seem to have issues with creating a competitor to their flagship CPUs, so they keep leaving the FPU off the part. In 2004, a CPU sans FPU is a pretty unlikely desktop box.
I'm very excited about the ARM Ltd part for this reason. Not only
Re:ARM servers (Score:4, Insightful)
Once we get processor and memory combined, we'll see performance increasing by several orders of magnatude. Processor architecture will matter even less, since emulation of *any* architecture will become trivial in terms of available processing speed. Your Thumb-like prediction will most certainly pan out to some magnatude.
Re:ARM servers (Score:2)
Re:ARM servers (Score:3, Interesting)
Look at embedded systems and you will see fresh new well thougth out solutions which have much lowwer memory requirements.
180M transistors means we could have e.g. 100Mb flash, 40Mb RAM and an ARM on the same chip.
That could do an awful lot in some apps!
Flash, SRAM, and DRAM. (Score:2)
Most modern flash memory uses multi-level storage, allowing several bits per cell (I'd known about 4 levels (2 bits), another poster mentioned 8 levels (3 bits)). Storage still only requires one transistor.
The way it works is that you have a FET with a floating gate. In "write" mode, you apply a high voltage t
Re:ARM servers (Score:3, Informative)
You're probably thinking of SRAM, in which a single bit cell requires 6 transistors. The advantages of SRAM:
- Data remains resident as long as the cell remains powered.
- With the exception of leakage, the only power required is for switching, making SRAM good for low-power applications.
That said, a single DRAM bit is about as simple as you can get. It consists of a single transistor and a c
Re:ARM servers (Score:2)
Yep. Of course I was reffering to analog EEPROM cells, such as those that were used in the ISD audio recording chips ;-)
Re:ARM servers (Score:2)
Re:ARM servers (Score:5, Informative)
Once we get processor and memory combined, we'll see performance increasing by several orders of magnatude.
This idea has been around for what is almost certainly longer than either of us have been alive. It turns out that there are problems.
The main problem is that no matter how much memory a system has, we find ways to use it. In the time I've been using computers, memory size has gone up four orders of _magnitude_, and I'm sure the greybeards listening will top that. The processor sitting in your machine right now has more on-die memory (the cache) than, say, an early XT had, but the tasks you're running have a memory footprint too large to fit. This is the price for being able to _do_ more than you could do on that old XT.
Another problem is with the structure of memory itself. You've heard of "fast, cheap, good - pick two"? Memory is "large, fast, densely-packed - pick _one_". The reason why integrated logic/DRAM processes tend to do one or the other badly is that DRAM and logic have to optimize transistor characteristics for exactly opposite things (high "on" current for logic, low leakage current for DRAM). Among other things, this means that DRAM is either slow or very power-hungry. SRAM is bulky no matter what you do - it's the cost of playing, when you have six transistors instead of one. Any kind of large RAM array is slow no matter what you do - you have to propagate signals across a huge structure instead of a smaller one.
The solution to date has been a hierarchical cache system, where small, fast, on-die memory is accessed whenever possible, and when that overflows, larger, moderately fast, on-die memory, and when that fails, DRAM. This works amazingly well, giving you almost all of the benefits of fully on-die memory for problems that fit in cache. Problems that don't fit in cache won't fit in on-die memory, so going with an on-die implementation doesn't help for them.
Progress in improving memory response times is made in two ways. The first is to use a better cache indexing algorithm that is less suceptible to pathalogical situations. In the simpler indexing schemes, you can end up with situations where a short repeating access pattern can hammer on the same small set of cache blocks, causing cache misses even when there's plenty of space elsewhere. Higher associativity and tricks like victim caches reduce this problem. Techniques like a "preferred" block in a set reduce the time penalty for high associativity, and techniques like content-addressable memory reduce the power penalty. This is still a field of active research - build a better cache, and you get closer to a system that _acts_ as if it has all memory on-die.
The second way of improving memory subsystem performance is to use memory speculation. This involves either figuring out (or even guessing) what memory locations are going to be needed and preemptively fetching their contents, or taking a guess at the value that will be returned by a memory fetch before the real result comes in. In both cases, you're masking most of the latency of the memory access, while paying a price for failed speculations (either in higher memory _bandwidth_ required, or in power for speculated threads that have to be squashed). Build a better address and data speculation engine, and you'll again approach performance of an impossible all-on-die-and-fast system.
In summary, it turns out that putting all of the memory of a general-purpose system isn't practical now and won't be as long as requirements for memory keep increasing. However, caches already give you performance approaching this for problems tha are small enough to _fit_ in on-die memory, and cache technology is constantly being improved. This is where effort should be (and is) going.
Re:ARM servers (Score:2)
Got ahead of myself.
What I'm trying to say is that any large SRAM array will be slower than a small SRAM array, and neither will have very high capacity. A DRAM array has high capacity, but is horribly slow. So-called "single transistor SRAM" is actually DRAM with a cache tacked on.
memory technology (Score:2)
My home PC also costs almost two orders of magnitude less than a PDP-1 did, even ignoring inflation.
John Sauter, greybeard (J_Sauter@Empire.Net)
Re:ARM servers (Score:3, Interesting)
Though not a _personal_ computer, I like many at the time ran programs in time-share environments at a university. When I started college in 1977 I got an account on the PDP-11/45 system, which came with some personal storage, access to BASIC, and all of 8K of core. Before that I had never touched a computer system. When I started serious projects I applied for more core, and got 16K.
Later as a graduate student I programmed Apple][ systems in hybrid BASIC/assembly
Re:ARM servers (Score:3, Insightful)
Re:ARM servers (Score:2)
Re:ARM servers (Score:2)
Sorry, I prefer cheap commodity computing. Such a scheme would be VERY expensive. An expensive crutch programmers who got a 'D-' in computer architecture because of an utter failure to comprehend the memory heirarchy. An all RAM on die scheme would be an enourmous waste of money, as vast, contiguous regions would sit idle. No one does this at any scale of computing because caching strategies get us the vast
Re:ARM servers (Score:2)
ARM6 *NOT* a server chip (Score:3, Informative)
If I recall correctly, chips prior to ARM6 had register 15 (ARM's PC) designed with the upper six bits reserved for status. Having a program address space of only 2^26 = 64 MB was a major obstacle, even for (successors of) Acorn's RiscPC, a desktop model. With that resolved in the ARM6 series, it is still unable to look beyond the 4GB boundary. In the 4 way SMP servermarket this is likely to become a major pain.
So either they found a nice way to add yet more MIPS per megaherz (or per watt) to serve a highe
ARM6 != ARMv6 (Score:4, Informative)
The other is ARM's latest version of the ARM architecture.
26-bit addressing limitations were removed ~14 years ago. I don't even think any of the more recent versions of the ARM architecture support it.
Re:ARM6 != ARMv6 (Score:1)
Re:ARM servers (Score:2)
Imagine a.... (Score:4, Funny)
What do you want, a cookie?
Seriously though, this would be great to run Linux on... Like a new Zaurus perhaps
Interesting (Score:5, Interesting)
The opposite of HyperThreading? 4 CPU's to one instead of 1 CPU to 2?
The only thing that I can guess they mean by simplifying is that a developer would not have to design a multi-threaded application to take advantage of the other threads.
Re:Interesting (Score:5, Informative)
Notice that SMP has been a dream to the ARM team from its early Acorn/Archimedes days on. It seems they finally got it working...
Re:Interesting (Score:2)
Re:Interesting (Score:1)
Being Cantabrigian, they probably preferred the Greek metaphor, anyway ;)
Re:Interesting (Score:2)
Re:Interesting (Score:2)
SCU (Score:2)
Re:Interesting (Score:1)
Synthesizable = can put it in an FPGA (Score:5, Interesting)
Synthesis of a core is analagous to compiling your software- except in an FPGA it is processing a hardware definition language like VHDL or Verilog to create the 'code' used to load the FPGA.
This is a big plus for people wanting to put a wicked fast processing unit in the core along with whatever custom IO goodies they can come up with.
Too bad its not open source, as there are other wicked fast processor cores available. For example Xilinx can license you to put a PowerPC in its FPGA cores.
Re:Synthesizable = can put it in an FPGA (Score:3, Informative)
Synthisiable to Silicon, for ASIC's mostly though people like Philips turn them into micro-controllers and Intel make a few Micro-processors, the idea mostly is you can put a LCD controller, SIM Card reader, DSP, etc all on one lump of silicon with an ARM processor and put it in your mobile phone.
And you don't licence a PowerPC core to put in a FPGA, you get a PowerPC chip actually inside the FPGA (Vertex2 Pro), any IP-Cor
Re:Synthesizable = can put it in an FPGA (Score:2, Informative)
Re:Synthesizable = can put it in an FPGA (Score:5, Informative)
There is this [cnn.com].
You can find the code easily. There are a couple of other clones, but I have not heard much about them. Another one is BlackARM developed in Sweden a couple of years ago.
I think these projects would be ok as long as they are instruction compatible, but not an internal clone. In which case ARM would pull out their lawyer dogs.
But there are a couple of other open source cores available, which IMHO would be smarter to use because you could do more with them without the fear of legal reprisal from ARM.
If you are designing an embedded system, you might could get by using such a core. The thing ARM has going for it is that commercial support and toolkits are available, which can be handy if you have a complex application that needs a lot of debugging. And there is a lot of third party support that you are not going to find with your homegrown core.
That being said, you could save a fair amount of money using an open core. But if you need to get something important out the door quickly (like a toy for christmas) you go with the commercial solution. Unless you have the necessary in-house resources to troubleshoot problems.
Just my
Re:Synthesizable = can put it in an FPGA (Score:2)
Re:Synthesizable = can put it in an FPGA (Score:2)
From the sounds of it, Arm found a way to make this go away [reed-electronics.com]
It probably is academic though. Any significant competitor to ARM that used their instructions would bring a lawsuit.
Re:Synthesizable = can put it in an FPGA (Score:2)
That a core is synthesizable does not just mean you can place it in a FPGA. It also means it can be targeted for any logic process.
I've frequently used soft cores in conjuction with my own logic ON asic/assp devices.
The advantage of soft cores are that they are easily retargetable to new technologies and is easier to integrate in a design as you don't need to make spe
Wave of the future. (Score:5, Interesting)
Re:Wave of the future. (Score:3, Interesting)
Also you don't have to refresh static ram, its more expensive but might pay off in terms of energy.
Jeroen
Re:Wave of the future. (Score:2)
Re:Wave of the future. (Score:2)
Re:Wave of the future. (Score:2)
In terms of power, I would think it depends entirely on the duty cycle. In terms of switching power, SRAM has a higher switching cost due to having more transistors. On the other hand, DRAM leaks power constantly AND has to have data restored on every read while SRAM has very low leakage.
Nice to have a 4 core CPU (Score:4, Interesting)
Re:Nice to have a 4 core CPU (Score:2)
Jeroen
Re:Nice to have a 4 core CPU (Score:1, Interesting)
Re:Nice to have a 4 core CPU (Score:3, Insightful)
S
Re:Nice to have a 4 core CPU (Score:2)
That's only 3 years away at Moore 1.
(I hereby define "Moore" to be the scale upon which the growth of computation power can be measured. Moore 1 represents a doubling every 18 months, Moore 2 a doubling every 9 months, Moore 0.5 a doubling every 3
Re:Nice to have a 4 core CPU (Score:2)
In three years, this design will only be used in embedded devices. It's only interesting for desktop use right now, and then only if you get four 550MHz cores. Otherwise a single higher-speed processor is going to beat its pants off.
Exactly what I was looking for! (Score:4, Funny)
Is any one else getting the impression that our entire industry is driven by penis envy [theregister.co.uk]?
"It's bigger, it's faster, stronger! More Power!" About the only flaw in my theory is the continuing trend of decreasing computer sizes. But I can atribute that to the fact that it lets people put them in their pockets.
BTW: If you actully use your CPU(s), this doesn't apply to you. Your penis is bigger.
Re:Exactly what I was looking for! (Score:2)
That's what SMP gives you. A single CPU can easily do anything I want, but by partitioning it, my Vorbis player doesn't slow my AutoCAD
Re:Exactly what I was looking for! (Score:3, Insightful)
No doubt their are people who need this kinda raw power. Rendering a movie is a good example.
But 99% of the people out there (and 99% of the software) can't really take advantage of that kind of power.
But darned if they don't HAVE to have the latest thing on the market. Like spending 4 times as much for bleeding edge equipment will keep their computers from becoming "out-dated". And I'm not just talking early adopters, I'm talking GrandMothers and Young Nerdlings.
People pay outrageous amounts for
MMP ARM server (Score:4, Insightful)
So, ARM are even lower power, they are designed quite correctly from the ground up[1] and the only thing that's missing is FPU. But the computer with 100 ARM CPUs would run faster than any ix86 today and probably would consume less power than the latest P4/K7/K8.
Give me for 64 proc (*4 cores per proc, so 256 proc) Linux machine anytime
Robert
[1] Anyone who knows internals of today ix86 processor from any vendor knows what a mess is it in order to use today's technology with ancient ISA like ix86.
Re:MMP ARM server (Score:4, Informative)
That's nice but, (Score:5, Interesting)
How will it fare against, say a Xeon with HT or 2 Opterons?
How will it stack up in price?
Re:That's nice but, (Score:1, Insightful)
Re:That's nice but, (Score:2)
It won't be able to heat up your house during winter like the Xeon with HT or 2 Opterons can.
This may not be so important during the summer months though.
Re:That's nice but, (Score:2)
This kind of product is designed for PDAs, where most products are going to 300-400mhz processors.
Check out PMC-Sierra's dual-core RM9000x2 (Score:3, Interesting)
WinCE, Symbian, PalmOS and Linux (Score:4, Interesting)
Why? (Score:4, Informative)
You don't use an opteron in the same situation as an arc core. Its a synthesisable mini processor used for controlling real time systems. It can be embedded in chips with custom VLSI logic to provide a platform for an operating system. Its not meant for competing with Opterons or any of the other such stupid ideas.
Why 4 cores?
Not all customers need 4 cores, some only need 1 (washing machines) or maybe 2. The system is therefore scalable to die size/power/cost requirements. Note its configurable, it does not have to have 4 cores. If I were a customer of arc I could chose how much die space to devote to the core and how much power I really needed.
4 cores, instead of one bigger more complex one is easier to engineer and get right. Look at modern graphics architectures, its the same principle (though one can argue about cache coherency).
Multiple cores would make dynamic power management much easier to handle I imagine. An entire core could shut down when its process(es) are not busy. A properly designed embedded system could benefit enourmously from this power saving and the hardware design is made relatively easy rather than trying to cut voltage for on one large core.
Embedded systems using arc cores often need to meet real time needs. One advantage of a multicore system would be to place a critical software component on a single core and, with correct use of memory, guarantee a fixed throughput rate of data. Of course I can use thread priorities but this makes things harder IMO. Maybe thats what they refer to by easier programming.
To me, this looks like a clean idea, which although not revolutionary in terms of an idea, does provide significant advantages for embedded device designers by being synthesisable.
Wroceng
(no association with ARM at all but I forgot my password temporarily)
Should Be A Boon For PDA's (Score:2, Interesting)
This would seem to hand in hand with the current thinking on on the fly OCR/language translation. I watched a show last night about a camera and PDA gizmo that could translate a road sign for you. I think that one did it via a server based imageing system. But if you do all that internal the posiblilites are endless, and hopefully not trivial, like SMP pong or really fancy ringtones.
low electical power + high CPU power
Nice! (Score:2, Informative)
ARM cores have a great advantage of having an incredibly low transistor count. As a result the simpler ARM chips tend to have incredibly good production yields. I don't know if that's true for the more complex ARM variants like XScale. This multi-core processor should also be an order of
ARM's 1st synthesizable proc? (Score:2, Insightful)
A little over a month ago I sat through a presentation by one of the guys near the top of ARM's research division...
It was a general overview of ARM's business model (it's an IP company) and products followed by some other material. During the presentation some cores were marked as synthesizable, others were marked as the opposite (I forget the specific term that was used).
To the best of my knowledge al
Re:ARM's 1st synthesizable proc? (Score:3, Informative)
Re:ARM's 1st synthesizable proc? (Score:2, Informative)
cheapest evaluation board?? (slightly OT) (Score:2)
Re:cheapest evaluation board?? (slightly OT) (Score:2)
Game Boy Advance, especially if you want to PLAY with it.
Clock for clock, how is it? (Score:3, Interesting)
X86s are supposedly awfully inefficient architectures, so would they come out on bottom? Where would various ARM, xScale, 68k, and PPC processors end up?
Although x86 CPUs have scaled up to some amazing clock frequencies, it seems like their growth has slowed. Intel seems to have implicitely acknowledged this since they're dropping the P4 line for an updated P3 architecture. AMD did the same thing with the Athlon64s, which have slower clock speeds but are faster in the end.
If it turned out that an ARM at, say, 600 MHz turned out to be as fast as a P3 at 1 GHz, then I would say the ARM could leave the embedded market and could become competition in the desktop market. If such systems were significantly cheaper, cooler, smaller, and less power hungry than similar x86 systems, I think they could seriously compete.
Re:If I had no Idea what I was talking about... (Score:1, Funny)
Mod him +5 insightful (Score:4, Funny)
Re:Hype (Score:3, Funny)
Re:Hype (Score:4, Insightful)
On a WorkStation, I would agree with you, but on any server with thread optimised applications, more threads = more power...
Once again, People think WorkStation, for things not designed for the WorkStation market
Re:Hype (Score:2)
"More simultaneously executing threads = more power"?
A single cpu can exeucte multiple threads, just that the cpu switches among them and executes only one at a given instant, which does not lead to higher performance.
Re:Hype (Score:3, Insightful)
arm cpu's being used mainly in devices with limited electrical power available anyways.. if this gets them more processing power per watt then all the better.
Re:Hype (Score:3, Interesting)
Re:Hype (Score:5, Insightful)
If the problems you want to solve are parallel enough why not?
Jeroen
Re:Hype (Score:3, Insightful)
[Rant]Why, oh _why_, do people keep horribly abusing the word "exponentially"?[/Rant]
Power goes up in direct proportion to the clock rate. This is a "linear" relation. If it was really "exponential", we'd be stuck running 10 MHz processors because anything else would melt.
For the really pedantic, the way to compute dynamic power dissipation is to figure out
Re:Hype (Score:2)
I've been running SMP desktops for years... (Score:5, Informative)
Incorrect.
As the subject line says, I've been running SMP desktop PCs for years. My current home PC is a dual 1GHz P-III, my wife's is a dual 850 and my Linux web/file/mail/whatever server is a dual 700 with a 12% overclock.
You can only figure on about a 40% performance increase with a dual processor desktop PC, but being able to play Quake and burn a DVD at the same time has it's advantages ;-)
As others have mentioned, multitasking is greatly enhanced - and two midrange processors are generally cheaper than one high-end processor.
Also, even though some applications aren't multithreaded, all modern desktop OS are - so you get a performance boost even running single-task applications. If you're into running Windows, Internet Explorer is multithreaded, as are all Microsoft Office applications. There's a real-world productivity boost using SMP machines.
Re:I've been running SMP desktops for years... (Score:4, Interesting)
Mind you, the guy isn't saying SMP is stupid- it makes sense in a lot of situations. But, it is something you pull out when a single, higher-speed CPU is not a possibility, whether that is the case due to lack of funds or whether a faster CPU just does not exist.
Here at work, I have a dual 500 MHz G4 which still holds it own, even with a relatively small amount of RAM, 256 MB. When this box was purchased, there was no option for a single-CPU 1 GHz box, and this is certainly the next best thing...
Re:I've been running SMP desktops for years... (Score:1)
The way I read the post was the *only* reason for SMP was if you reached an architecture limit - and I disagree with that.
Hell, it wouldn't be the first time I've misread a post here ;-)
On multiuser systems the benefits to SMP are clear. IM frequently less than HO running two processors at 50% is considerably more efficient than running one at 100%.
Re: (Score:2)
Re:I've been running SMP desktops for years... (Score:2)
E.g. it only allocates up to 50%, and leaves the other 50% for other stuff (GUI, DVD burning etc).
But then people will complain if only 50% of their CPU is used, oh well...
While two midrange processors are cheaper than one high end processor, SMP motherboards so far have been rather more expensive. Anyway most people can't afford the really hi
Re:Hype (Score:5, Interesting)
You bring up an interesting point. The reason this might be valuable is because ARM processors are known for their low current and energy saving features.
Almost always when you max out the clock speed on a chip the current drain rises quickly.
From the article it can be surmised that this chip runs at a cool 2 watts running full out, and
As as aside, there are cell phones that use a dual ARM core, one doing control duty and another doing DSP work.
Re:Hype (Score:2)
Re:Hype (Score:5, Informative)
1/2 GHz quoted for this core may not sound a lot, but there are some good reasons for it:
- ARM cores use a shorter pipeline than Intel cores (in general). This requires less logic to get a good throughput of operations. Less logic means less area (less cost) and less power consumption. These are important in embedded applications (you don't want your phone to be putting out 50W and costing $200).
- These cores are synthesisable. This means that ARM will deliver a "model" of the device, and customers can translate this to a silicon layout on their own process, and they can integrate peripherals, memory etc. on the same silicon. Getting a higher clock speed requires custom logic which is hard to translate between processes. Essentially the processor has sold separately as a piece of silicon, and this means a slow off-chip interface to the rest of the system.
For a multi-threaded or multi-process application such as this core is targetted, using MP cores makes more sense than using a single high-speed core and switching between processes all the time. For one thing you save all the context switching overhead.
Re:Hype (Score:4, Interesting)
The purpose of having a multiprocessor on a single core is to make consumer devices (read: audiovisual stuff) more versatile, by allowing them to dedicate, say, one core to processing the signal you're watching, one to processing the signal you wish to record, one to handle the disk I/O, and one to watch over everything and make sure your favourite show is recorded without glitches.
This isn't aimed at the desktop, or at shrinking supercomputers to the size of your thumb, or any other fantasies you may while away your idle cycles with.
It's aimed fairly and squarely at the embedded and consumer device markets, where it will produce benefits, and will likely make ARM a tidy sum in license fees.
Re:Arm != Intel ? (Score:3, Informative)
Intel bought part of DEC (Digital), which had, in its product portfolio, the StrongARM processor. StrongARM is a DEC implementation of the ARM Instruction Set Architecture (version 4 if you care).
ARM is still an separate, publically listed company. XScale is an Intel implementation of the ARM ISA (version 5TE I think). Intel pays ARM to use their architecture.
ARM also designs implementations of the ARM ISA and licences these designs to chip designers to include in System-on-Chip designs.
Re:Just a small detail (Score:2)
Re:Just a small detail (Score:2)
Quick and dirty integer divide. (Score:2)
You can also have fun with series expansions and other tricks for tur