ARM releases free Cortex-M processor cores for FPGAs

[paulgerhardt]

The press release linked by OP doesn't give the full story. For a better perspective see https://abopen.com/news/arm-offers-free-as-in-beer-cortex-ip...

If you're just joining us, Arm very much sees the up and coming RISC-V stack as an immediate threat to the future of their business and is taking pro-active countermeasures - doing everything from awkward, backfiring smear campaigns against RISC-V[1] to straight up license dumping their own product to prevent developers jumping ship.

It's interesting to see because RISC-V is wonderful and Arm seems to recognize that. Arm Holdings is acting rationally as someone in a privileged competitive position would do. At the same time, big players like Western Digital are migrating to RISC-V so Arm is internally freaking out [2].

[1] https://www.theregister.co.uk/2018/07/10/arm_riscv_website/

[2] https://www.theregister.co.uk/2017/12/01/wdc_risc_v_edge_str...

[ChuckMcM]

Pretty much exactly right.

What I found interesting initially was how the 32 bit CPU was disrupting the 8 bit CPU market. People using Cortex M0 chips where they used to use ATMega chips. Identical package size, faster, more resources, not too much more memory. And some unreal bargains[1].

And now as FPGAs get cheaper and cheaper, RISC-V was becoming the default 'soft' processor because everything else cost money and didn't have any sort of ecosystem. Amazing times.

[1] Not sure how these folks make money -- https://satoshinm.github.io/blog/171212_stm32_blue_pill_arm_...

[snaky]

Big and small players are interested indeed, from WD, Alibaba and Huami to 'some 300 companies already looking at or developing with RISC-V in China'[1], but not because RISC-V is so wonderful, it's just not bad and just enough for many tasks - and it's basically free.

[1] https://www.eetimes.com/author.asp?section_id=36&doc_id=1333...

[jgome]

Kinda off-topic, but I feel like they could gain a lot by opening their graphics stacks or simply by letting FOSS devs work on them, instead of making their work more difficult/impossible (see: history of the FOSS lima driver).

[stcredzero]

If you're just joining us, Arm very much sees the up and coming RISC-V stack as an immediate threat to the future of their business and is taking pro-active countermeasures

By any chance, does anyone know if Intel is funding RISC-V? According to the logic of "Commoditizing the Complement" one way of hurting a competitor is to make their product a commodity.

[dang]

Ok, we changed the URL to that from https://www.arm.com/company/news/2018/10/arm-expands-design-.... Thanks!

[zekevermillion]

Is there some way ARM could make money supporting an open IP like RISC-V, analagous to Red Hat for Fedora Linux? Obviously, not a perfect analogy, but...

[LogicCowboy]

This is ARM's definite response to RISC-V. As people develop their FPGA products, they will have to decide what their long term target is. If the intent is to eventually turn the code into an ASIC, RISC-V maybe the economically more sensible solution since there is no licensing costs there. However they will have to be patient with the toolchain. If the idea if the code will only be a pet project, wouldn't benefit from RISC's customization abilities, or long term is expected to use an ARM core, this is definitely the right pick. The ARM toolchain being more mature is a draw for many hardware developers.

I'm definitely very interested in trying a project with either RISC-V or ARM.

[Zenst]

Equally by offering this for Xilinx, it makes them more palatable over Altera offerings (owned by Intel). So a very tactile move on many levels.

But as an end user, I like competition like this, as long as there is competition tomorrow.

[kbumsik]

Wow, not only FPGA-optimized Cortex-M1, they also releases Cortex-M3, one of the most popular MCU IP.

BTW, are there many applications integrating a MCU core with FPGA rather than a AP core? I only have seen Xilinx products that uses Cortex-A core.

[TomVDB]

Super small CPU cores are fantastic for complex FSM replacement, especially on an FPGA which has unused block RAMs (so using them is essentially free.)

I’ve seen cases with relatively complex pure HW FSM being replace by a small CPU and 1KB of RAM where the logic used by the CPU ends up smaller than the FSM.

But now the CPU is programmable, so you can iterate much quicker in case of bugs, without the need to reaunthesize.

A good example are SDRAM controllers: almost all of them have a small CPU inside the controller that is used for calibration training.

[noselasd]

> BTW, are there many applications integrating a MCU core with FPGA rather than a AP core? I only have seen Xilinx products that uses Cortex-A core.

It's common enough that you'll have them available as part of the FPGA toolchain , Xilinx has Picoblaze/Microblaze and Altera has NIOS-II

[xfer]

Here is a ice40 fpga board that uses a cortex-M4 https://www.tindie.com/products/Folknology/blackice-ii .

[monocasa]

It's not unheard of to throw a soft core in there too, but in the past it'll be something like a Microblaze. An MCU vs. an AP are pretty orthogonal as it's pretty hard to cycle counting real time determinism out of an AP.

[vanjoe]

Yeah the newer zynq-MP have a 4 core A53 as well as two realtime class cores on there.

[phsilva]

Let the battle begin! Wonder how RISC-V movement in the open source ISA front has influenced this decision.

[ingenieroariel]

Sounds really good. Is it only free as in free beer or editable too?

The interesting applications for RISC-V are Vector Extensions and other application specific mods.

[Palomides]

"DesignStart Eval enables completely free access to fixed-configuration Cortex-M0 and Cortex-M3 and full subsystem RTL for evaluation, prototype, teaching, and research. Available to all*, the packages can be downloaded instantly, requiring only a simple click-through agreement. "

and if you want to make a product,

"DesignStart Pro enables access to the full Cortex-M0, Cortex-M3, and subsystem RTL. Available to companies for commercial use with a no-risk, $0 license fee and success-based royalty model. Access to the IP can be requested online, requiring the signing of a simplified license agreement."

so free as in... kinda freeish free trial.

[kbumsik]

It is for Xilinx FPGAs only so at least it is not open-source friendly.

[ISL]

Came to the comments for the same question. The difference between beer and speech is important here, as the impact of a free-as-in-speech open-source design would be substantial.

Either way, thanks, ARM!

[phire]

Beer. Pretty sure they will be precompiled RTL blobs.

[jeanmichelx]

You can add custom memory-mapped hardware though

[valarauca1]

The commetization of the CPU market was bound to happen eventually. As modern production techniques for chips and FPGA programming start to converge rapidly.

What is the ETA until we get a GNX "GNX is Not X86"? An Open source i386 core that people can run existing applications on? Much like GNU offered a standardized FOSS platform people could run existing Unix workloads on.

[0xcde4c3db]

There's ao486 already [1] [2]. I seem to recall that there are a few corners where it's not 100% complete/compatible, but it's complete enough to boot Windows 95 and Linux (assuming a Linux distro with 486 support, now an endangered species), and run some classic DOS games/demos. It doesn't run at a speed equivalent to a "real" 486, at least on a cheap FPGA.

[1] https://github.com/alfikpl/ao486

[2] https://www.youtube.com/playlist?list=PL2QcW6r3MlDThUnC8cA-r...

[phkahler]

I'm not sure what value there would be in a 368. You can emulate that on a modern CPU if you need legacy software support. Otherwise just use RISC-V, it already runs Linux and thousands of programs. Oh, and it's got a 64bit version too.

[Taniwha]

A great question .... all the 386 patents are out of date now right?

[faragon]

I would love ARM releasing ARM1 and ARM2 processors (both with a 3-stage pipeline) for FPGAs, not because of economical interest, but because of historical and coolness purposes. And more, so you could e.g. run a synthesized Acorn Archimedes from a FPGA, for free, running Linux on top of it :-)

[monocasa]

They come close to that here, a gate level simulation of an ARM1.

http://visual6502.org/sim/varm/armgl.html

[peter_d_sherman]

Free != Open Source. Are NDA's/vendor secrecy required? Is the core, in whatever form it is provided in, not obfuscated in any way, and well documented? Does ARM permit companies using it to modify the design? Free != Open Source.

[spilk]

so how many LE's do these cores consume compared to a similar RISC-V or any other CPU design? Are there advantages just beyond familiarity of ARM?

[stevefan1999]

Why did the article claim that "Free and Open Source Silicon" is a threat to ARM?

Thinking further, we already have RISC V up and running, but doesn't it really impact traditional chip OGs like ARM and Intel?

[nickik]

Of course RISC-V impacts ARM and to a lesser extent Intel. Most costumer that goes to RISC-V would have picked ARM.

Of course changes like that don't happen in 1-2 years. RISC-V is still young, 2015 is when it actually went public with the foundation.

Not to mention that back then many things we not frozen, so now basically everything you need for a Linux stack is frozen.

[stcredzero]

How suitable is RISC-V for military use? If we were to redesign the F-16 from scratch in 2018, would be able to make it using hardened Arm or RISC-V chips in place of x86 processors?

[mmirate]

The avionics and EW systems are probably being redesigned on a much more regular basis than ... well, than almost any other component of a fighter.

[nickik]

DARPA is has RISC-V projects. There was a Keynote by DARPA:

https://www.youtube.com/watch?v=9hIA4ZIXtxA

https://content.riscv.org/wp-content/uploads/2017/12/Wed-104...

I think the RISC-V startup called 'Denver' is also working with DARPA.

[mycall]

I wouldn't assume the F-16s have Von Neumann.

[jhallenworld]

Will there be a version for Lattice FPGAs? These are more interesting targets because they are lower cost than Altera or Xilinx.

[mmirate]

Single-digit Cortex-M models? Dinosaurs, all.

Hold your applause until we can see the innards of an AArch64 implementation.

[jononor]

Several billions of such chips are shipped per year. Many established segments are still moving from 8 bit to 32 bit micros, and new segments are still growing rapidly. So shipments of Cortex-Mx devices is likely to grow quite a bit still.

[duskwuff]

Cortex-M is still highly relevant in embedded development. While some double-digit Cortex-M cores theoretically exist (Cortex-M23, -M33, and -M35P), there are virtually no parts in production which use them; the current state of the art is Cortex-M7.