Slashdot Mirror
"Open-Source" ARM7 Core May Be On The Way
jbp4444 writes: "From EE Times:
Swedish students weigh next step with ARM7 clone.
A group of Swedish students implemented an ARM7 core on a Xilinx chip as part of a PhD thesis - but they used only publicly available information and documentation to do it. So they may be able to "open-source" the VHDL code that they wrote. This would enable others to have royalty-free access to an ARM7 core. They are still investigating their alternatives, so it is far from a done deal. Oh yeah, at the end of the article it mentions "it's still not clear whether the BlackARM processor works properly" -- due to the time constraints of a PhD thesis, they seemed to have skimped on the testing of the chip! [but note, they say it does run applications --t] In an odd coincidence, the same issue of EE Times (Jan. 29) also had a story on automakers investigating Linux for their in-car entertainment systems. Royalty-free OS coupled with potentially royalty-free hardware has an obvious appeal to many industries."
Contrast this with Sun Microsystems who use the SPARC processor under license. As far as I'm aware, they don't even manufacture SPARCs themselves, but rely on a third party foundry. Why is this relevant? Because SPARCs are also used by many vendors and you can even get the chip architectures if you wanted to implement it yourself, then have your design properly verified.
ISTR that OpenCores were warned not to do an open source ARM compatible processor by ARM. This was probably because ARM is really an IP only company, and if someone comes along and builds their own which is free, then their entire market could collapse.
Then again, the ARM7 processor isn't ARM's latest offering, so they may be lenient.
If you want to know more about the ARM 7 processor, then here is the place to go.
Er, hello? We're talking FPGAs here - Field Programmable Gate Arrays. Yes, you would be able to download the latest core and configure an FPGA hardware device according to the VHDL code.
:)
Note guys, two things:
1). They haven't tested it anywhere near what the
average chip gets before it is even publically
mentioned.
2). The core runs very slowly at the moment and
lacks "basic" functionality like pipelining
and caching.
Still, it's cool and nice to see this sort of thing (see also Open Cores project, etc.) but at the moment it's a bit of academic fun and nothing more - you won't be throwing away your Athlons for now
--jcm
Whine, whine, whine, not useful because I can't fab the chip.
Neither do they. It's a Field Programmable Gate Array. I know most of slashdot are just software people, and don't really understand hardware so let me explain: An FPGA is built of many Combinational Logic Blocks (CLB's) with flip flops, buffers, and gate level logic. To implement an FPGA, a fuse file is created from an HDL (Hardware Design Language). This fuse file is used to determine which internal connections to the FPGA will be active and inactive.
Programming an FPGA from a computer isn't too tough. A cable needs to be made up that can handle JTAG communication with the part, and voila. It's funny to see people whining that progamming an FPGA is too hard, but on other stories saying they're going to build a portable atari, or hack their Tiva box.
FPGA's can be very useful for smaller runs of a chip, especially if the design has a good chance of changing. Since a lot of FPGA's are reprogrammable, screwing up the design doesn't have as big of an impact as screwing up an asic. Also, Asics only become economical when you make a ton of them.
For example, Motorola will probably use Asics for the hardware for their phones, since they make millions. On the otherhand, Nortrhop Grumman will use FPGA's for their missile jammers, since they make runs in the 100's.
FPGA's are designed so that their can be a multitude of different arrangements of connections inside the FPGA. This leads to not being able to optomize for speed as much. They can do most of the things Asics can do, but not as fast or efficiently, since they were designed to be multi-purpose.
DAve
Still, it's cool and nice to see this sort of thing (see also Open Cores project, etc.) but at the moment it's a bit of academic fun and nothing more - you won't be throwing away your Athlons for now :)
and that's really the issue here: putting cores into an FPGA is nothing new, but i think the software-leaning slashdot crew need to get a handle on the sacrifices you make by using an FPGA (especially an SRAM-based FPGA like Xilinx or Altera). FPGAs are painfully slow when compared to an ASIC; they're really not even comparable. and when this chip doesn't even implement pipelining, it's going to have very few applications outside of casual, academic use.
while it may sound like a godsend to use VHDL to create hardware and put it in an FPGA, there's a really big difference between hardware and software. there are so many other steps that occur in creating an ASIC after the VHDL synthesis process, such as layout and floorplanning, that optimize an ASIC for speed and power consumption. an FPGA is only used to get a "rough" idea of the functionality of the chip, or to put simple "glue" logic on a board that doesn't justify spinning an ASIC. again, you really can't compare an FPGA-based processor to a real fabbed processor.
additionally, if you're looking to create a chip that you can actually use in any sort of device with reasonable speed and power consumption, you'd be much better off using a non-volatile technology FPGA from Actel or QuickLogic. while you sacrifice reprogrammability, you'll gain considerably faster speeds, considerably lower power consumption, and a lower cost chip. once you program these FPGAs they're programmed for life (so if you make a mistake you'll have to throw it out), but if you synthesize your design sufficiently using software, the benefits of such a device are far outwieghted by their lack of reprogrammability.
at any rate, the dream of "open source" hardware is a nice one, but it's not nearly as golden an opportunity as you'd think by reading the slashdot comments. hardware and software are two totally different beasts, and the tools and techniques that work on one are not guaranteed to work on the other. after working in the hardware and semiconductor fields long enough i realize that hardware companies have the really solid business models, and aren't going to see opensource as competition anywhere in the forseeable future. in fact, opensource is being embraced by the semiconductor industry to increase the "value add" of the hardware itself. i personally push Linux at my company as much as possible, as i firmly believe that selling software isn't a solid business model unless that software is highly specific, or your company enjoys a monopoly in your industry. as much as this community may want it, opensource hardware is a long way off. you'd be much better off working with hardware companies to show them why funding opensource projects is in their best interest (and as a nice co-incidence, also in the best interest of the open-source community).
- j
I don't think the car industry is going to be all that excited about getting a 16Mhz pair of CPUs on a chip that costs a lot more then a "real" 200Mhz ARM. One that can actually multiply numbers in hardware, and you know, has been tested.
A lot can come up going froma simulated FPGA design to the real hardware. Sometimes it can be fixed just by bringing the clock speed down a bit, but other times if you had an overdriven line or something the simulator will be great and real hardware a nightmare. Of corse I have done very very little FPGA work (population count, a NFA evaluator, a few other toy projects).
None of this means the BlackARM is crap, if someone works on it for a long time it could be useful, maybe optmised for an ASIC so it is cheeper (in quantity), and faster. Or maybe just using it (as is) to exparament with CPU perphrial integration (15Mhz CPU with an AES engine). It definitly had value in providing a duel CPU on a chip test platform for a lucky (hard working) Phd candiate...
P.S. I'm assuming the pair of ARMs is on a Xylinx Virtex baised on the 16K RAM number. The Spartin line doesn't have nearly that much RAM, but that is a lot more affordable, starting at under $1. The Virtex is still quite costly, it has a lot more gates, the SRAM, and and a higher max clock if you keep the circuit chains short (i.e. pipeline).
Royalty free chips have been around for quite a long time now... Visit free_ip.com and browse their cores if you like. You see, this is nothing special, nothing new, just the spin pit on the story makes it sound so amazing and incredible... But this is par for the course, it's just another day at slashdot.