Anyone really use those opensource CPUs (OR1K, Lattice Mico32, Leon)?

Well it's not new at all, but I've just discovered Yet Another Open Source 
RISC core -- Lattice's Mico32.  It comes with GNU tool-chain (making the 
software-development side similar to OpenRisc 1200?)  and even has a 
built-in debug-module.

How popular these Opensource cores really are?  I know the Opencores EMAC 
10/100 gets a lot of use in commercial ASIC projects.  But the CPU-cores 
rarely get the same attention (mostly just academic or government-funded 
stuff.)  Could someone explain why?

Is it their performance (IPC, area, power-consumption)?  Is it lack of a 
supported embedded O/S port? 

Xilinx User wrote:
> Well it's not new at all, but I've just discovered Yet Another Open Source 
> RISC core -- Lattice's Mico32.  It comes with GNU tool-chain (making the 
> software-development side similar to OpenRisc 1200?)  and even has a 
> built-in debug-module.
> 
> How popular these Opensource cores really are?  I know the Opencores EMAC 
> 10/100 gets a lot of use in commercial ASIC projects.  But the CPU-cores 
> rarely get the same attention (mostly just academic or government-funded 
> stuff.)  Could someone explain why?
> 
> Is it their performance (IPC, area, power-consumption)?  Is it lack of a 
> supported embedded O/S port? 

  What's your question exactly - why FPGA cores are not seen more in 
ASICS ? - I get the impression Leon is doing quite well, in its niche.
  Mico32 is very new, and is really the first open source FPGA-centric 
core, so I'd expect it will show up in ASICs.

  Would you count a NIOS II licensed for ASIC use, either via the
Altera flow, or in a full asic.

  Of course, ASIC design starts are a tiny fraction of fpgA design 
starts, so any core  usage in that direction has to be small.

-jg

On 11 Jul, 05:29, "Xilinx User" <anonym...@net.com> wrote:
> Well it's not new at all, but I've just discovered Yet Another Open Source
> RISC core -- Lattice's Mico32.  It comes with GNU tool-chain (making the
> software-development side similar to OpenRisc 1200?)  and even has a
> built-in debug-module.
>
> How popular these Opensource cores really are?  I know the Opencores EMAC
> 10/100 gets a lot of use in commercial ASIC projects.  But the CPU-cores
> rarely get the same attention (mostly just academic or government-funded
> stuff.)  Could someone explain why?

Risk. Spending a couple of hundred k on a CPU with commercial support
is not that big a deal if you're making ASICs.

> Is it their performance (IPC, area, power-consumption)?  

Performance should be pretty comparible to the low-end commerical
offerings. Something like Mico32 is very much stripped down to
minimize LUT count, so some of the bells ans whistles you'll find in
dedicate ASIC CPUs are missing.

Cheers,
Jon

> Performance should be pretty comparible to the low-end commerical
> offerings. Something like Mico32 is very much stripped down to
> minimize LUT count, so some of the bells ans whistles you'll find in
> dedicate ASIC CPUs are missing.

Of course the flip side is when you try to prototype an ASIC CPU in an
FPGA. Laughable performance.

Cheers,
Jon

> Well it's not new at all, but I've just discovered Yet Another Open Source
> RISC core -- Lattice's Mico32.  It comes with GNU tool-chain (making the
> software-development side similar to OpenRisc 1200?)  and even has a
> built-in debug-module.

I've also noticed the lm32. It is really well documented. My only
objection (but hopefully this will change, i think it is under
consideration) is that Lattice provides only Verilog sources (which is
the language of preference for me).

A quick sum-up would include: PicoBlaze, MicroBlaze, Nios-II,
LatticeMico32, LEON2/3, OpenRISC. It would also be proper to add here
some bytecode interpreter engines (most notably JOP), but they are not
intended for general-purpose apps.

All the above are 32-bit machines except PicoBlaze. I have added
PicoBlaze in the list, because i find it really useful and a very
powerful processor for control-oriented applications. It has
predictable real-time performance and a large number (up to 256) of i/
o ports. I have recently set up a couple of lab exercises (one with
PicoBlaze solo and a second one with a  RISC core of mine and a
PicoBlaze) and i'm very positive over PicoBlaze.

> How popular these Opensource cores really are?  I know the Opencores EMAC
> 10/100 gets a lot of use in commercial ASIC projects.  But the CPU-cores
> rarely get the same attention (mostly just academic or government-funded
> stuff.)  Could someone explain why?

It is strange but all the above RISC cores have good toolchains so
someone would expect a wider adoption (adoption is good for the
vertical markets they are intended to for the time being). The
positive thing here is that there is no way but up. Embedded
processing and FPGAs will grow as CLB counts will rise and power
consumption (hopefully) will drop).

> Is it their performance (IPC, area, power-consumption)?  Is it lack of a
> supported embedded O/S port?

And most of the 32-bit cores have at least some kind of support for
embedded OSes (RTEMS, uClinux and others even commercial ones like
uCOS series).

But finally i donnot understand if there is a question posed here. Do
you have to choose between a open core and a closed-source solution.
Or are you between using a programmable processor core and using
something more customized for your case?

Nikolaos Kavvadias

> A quick sum-up would include:  MicroBlaze, Nios-II,

Since when were these open source?

Cheers,
Jon

Jon Beniston wrote:
>> A quick sum-up would include:  MicroBlaze, Nios-II,
> 
> Since when were these open source?
> 

For microblaze since the 11 october 2006 ;)

http://groups.google.com/group/comp.arch.fpga/browse_frm/thread/f26991bc41bd42bd/ee347c3e854061b3?lnk=gst&q=Microblaze+source&rnum=10#ee347c3e854061b3


	Sylvain

On Jul 11, 4:37 pm, Sylvain Munaut <tnt-at-246tNt-
dot-...@youknowwhattodo.com> wrote:
> Jon Beniston wrote:
> >> A quick sum-up would include:  MicroBlaze, Nios-II,
>
> > Since when were these open source?
>
> For microblaze since the 11 october 2006 ;)
>
> http://groups.google.com/group/comp.arch.fpga/browse_frm/thread/f2699...
>
>         Sylvain

OK, my apologies for the Microblaze, that was a strange story :)
But regarding Nios-II, i think the sources are there, but just not
portable across other FPGA architectures.
Am I right?

Nikolaos Kavvadias

On 11 Jul, 14:48, Uncle Noah <n...@skiathos.physics.auth.gr> wrote:
> On Jul 11, 4:37 pm, Sylvain Munaut <tnt-at-246tNt-
>
> dot-...@youknowwhattodo.com> wrote:
> > Jon Beniston wrote:
> > >> A quick sum-up would include:  MicroBlaze, Nios-II,
>
> > > Since when were these open source?
>
> > For microblaze since the 11 october 2006 ;)
>
> >http://groups.google.com/group/comp.arch.fpga/browse_frm/thread/f2699...
>
> >         Sylvain
>
> OK, my apologies for the Microblaze, that was a strange story :)
> But regarding Nios-II, i think the sources are there, but just not
> portable across other FPGA architectures.
> Am I right?

Sure, you can buy access to the source in the same way you can buy the
source to an ARM. Not quite Open Source though.

I think Xilinx do have HDL source for MicroBlaze, but it isn't that
much cheaper than buying a license for a real CPU that comes with
support ;-)

Cheers,
Jon

Thanks everyone, for the replies. My question was vague and poorly
worded because I don't have a good grasp on what constitutes a
"FPGA CPU-core"and an "ASIC CPU-core."  Microblaze and Nios-II
obviously are architected around the unique device-features of their
respective vendors.  But when it comes to the Opensource offerrings,
I didn't see the same trend (maybe I didn't look close enough?)

Picoblaze -- is that safe for ASIC-use?  I was under the impression
Xilinx's license-agreement limits it to Xilinx devices only.