Parts obsolescence is biting again, and at least one of my EEs is
insisting that we spin replacement boards with soft-core processors in
FPGAs.

There are several things I don't like about that.

First, how robust are these systems.  What if power is lost during
updating the configuration device?

Second, I don't like the holy wars among our EEs.  Most of them use
Altera and wouldn't touch Xilinx to save their lives.  But one guy
uses only Xilinx and won't give the Altera rep the time of day.  This
hasn't bothered me up until now, when we put together a peripheral
that is accessed to a microcontroller or DSP, because we define an
interface and they meet it.  I don't need to care who the FPGA source
is.

But if we're talking soft core, I'm not going to allow our embedded
software department get saddled with supporting both NIOS and Micro
Blaze.

So third, I'd be grateful for any experiences with either soft core,
or even better both, with a comparison between the two.

And does anybody have any experience with the synthesizable ARM soft
core for FPGA?  Unless there's a serious handicap, I'd prefer ARM if
we do soft core, we've already good tools and programmer experience.

Any and all comments, real or delusional, welcome.

-- 
Jack Klein http://JK-Technology.Com
FAQs for
news:comp.lang.c http://c-faq.com/
news:comp.lang.c++ http://www.parashift.com/c++-faq-lite/
news:alt.comp.lang.learn.c-c++
http://www.club.cc.cmu.edu/~ajo/docs/FAQ-acllc.html

Jack Klein wrote:

> So third, I'd be grateful for any experiences with either soft core,
> or even better both, with a comparison between the two.

Do you already have an FPGA on the board? If not, I think you'd be bloody
crazy to go soft-core. Your EE's just want new toys to play with if
they're pushing to stick an FPGA on there solely for that reason...

If you already have an FPGA, how much headroom do you have in the device?
How much bigger will you need to go to add a soft-core in there? How much
grunt do you need? I'm guessing a little if you're considering ARM. What's
the price difference in FPGA silicon?

I've had quite a bit of experience with NIOS in a number of different
projects. Overall it's been relatively successful, though one project
ended up in the trash-can because of robustness issues that we couldn't
pin down - using uCOS-II and 3rd-party IP stack and we couldn't prove it
wasn't our code, though a port of our code to a micro ran without
problems. So to be clear, I'm pointing my finger at the software
libraries, not the NIOS-II itself.

Oh yeah, the IDE is Eclipse (which I hate with a passion) and the debugger
is so buggy it's next-to-useless. So bear that in mind.

They really come into their own when you need to glue logic/peripherals to
the core that can also go inside the FPGA. Having said that, a lot of the
stuff might already be tacked onto a micro anyway - SPI, I2C etc.

For the record, I wouldn't touch Xilinx with a 10-foot clown pole either.

Regards,

-- 
Mark McDougall, Engineer
Virtual Logic Pty Ltd, <http://www.vl.com.au>;
21-25 King St, Rockdale, 2216
Ph: +612-9599-3255 Fax: +612-9599-3266

On Nov 6, 6:00=A0am, Jack Klein <jackkl...@spamcop.net> wrote:
> Parts obsolescence is biting again, and at least one of my EEs is
> insisting that we spin replacement boards with soft-core processors in
> FPGAs.
>
> There are several things I don't like about that.
>
> First, how robust are these systems. =A0What if power is lost during
> updating the configuration device?
>
> Second, I don't like the holy wars among our EEs. =A0Most of them use
> Altera and wouldn't touch Xilinx to save their lives. =A0But one guy
> uses only Xilinx and won't give the Altera rep the time of day. =A0This
> hasn't bothered me up until now, when we put together a peripheral
> that is accessed to a microcontroller or DSP, because we define an
> interface and they meet it. =A0I don't need to care who the FPGA source
> is.
>
> But if we're talking soft core, I'm not going to allow our embedded
> software department get saddled with supporting both NIOS and Micro
> Blaze.
>
> So third, I'd be grateful for any experiences with either soft core,
> or even better both, with a comparison between the two.
>
> And does anybody have any experience with the synthesizable ARM soft
> core for FPGA? =A0Unless there's a serious handicap, I'd prefer ARM if
> we do soft core, we've already good tools and programmer experience.
>
> Any and all comments, real or delusional, welcome.
>
> --
> Jack Kleinhttp://JK-Technology.Com
> FAQs for
> news:comp.lang.chttp://c-faq.com/
> news:comp.lang.c++http://www.parashift.com/c++-faq-lite/
> news:alt.comp.lang.learn.c-c++http://www.club.cc.cmu.edu/~ajo/docs/FAQ-ac=
llc.html

Hi Jack,

I am one who loves to play around with soft-cores,
yet I would also stay unless you have REAL valid reasons
to use a soft-core do not go that path.
I bet your EE guys can not give valid reasons
(or that I would be able to invalidate their reasons)

1) obsolete - dont fool your self, FPGA vendor soft-core do get
obsoleted as well!
2) FPGA vendor soft-core is actually a client-trap vendor lock-in

now, Cortex-M3 RTL code is really beatiful, small and easy, basically
you just
select ITCM/DTCM sizes, number NVIC interrupts, and you are done
and it useable on any FPGA with enough resources, so truly vendor
independant

optionally there free Coldfire (original freescale) core available for
Cyclone-3
(for other FPGAs there is license fee)

Antti

On Nov 6, 5:00=A0pm, Jack Klein <jackkl...@spamcop.net> wrote:
> Parts obsolescence is biting again, and at least one of my EEs is
> insisting that we spin replacement boards with soft-core processors in
> FPGAs.

?? Do you think FPGA's don't go obsolete as well ?

There is a lot more to go wrong in a fpga flow, so unless
you NEED the fpga for another reason, this is not a good
basis for a decision.?

What parts have gone obsolete, and why ?

There are things you can do, to mitigate obsolescence - like
chosing multi sourced parts, and designing your code and PCBs,
so that a Physical part swap, is not a high-impact step.


-jg

Antti wrote:
> On Nov 6, 6:00 am, Jack Klein <jackkl...@spamcop.net> wrote:
>> Parts obsolescence is biting again, and at least one of my EEs is
>> insisting that we spin replacement boards with soft-core processors in
>> FPGAs.
>>
>> There are several things I don't like about that.
>>
>> First, how robust are these systems.  What if power is lost during
>> updating the configuration device?
>>
>> Second, I don't like the holy wars among our EEs.  Most of them use
>> Altera and wouldn't touch Xilinx to save their lives.  But one guy
>> uses only Xilinx and won't give the Altera rep the time of day.  This
>> hasn't bothered me up until now, when we put together a peripheral
>> that is accessed to a microcontroller or DSP, because we define an
>> interface and they meet it.  I don't need to care who the FPGA source
>> is.
>>
>> But if we're talking soft core, I'm not going to allow our embedded
>> software department get saddled with supporting both NIOS and Micro
>> Blaze.
>>
>> So third, I'd be grateful for any experiences with either soft core,
>> or even better both, with a comparison between the two.
>>
>> And does anybody have any experience with the synthesizable ARM soft
>> core for FPGA?  Unless there's a serious handicap, I'd prefer ARM if
>> we do soft core, we've already good tools and programmer experience.
>>
>> Any and all comments, real or delusional, welcome.
>>
>> --
>> Jack Kleinhttp://JK-Technology.Com
>> FAQs for
>> news:comp.lang.chttp://c-faq.com/
>> news:comp.lang.c++http://www.parashift.com/c++-faq-lite/
>> news:alt.comp.lang.learn.c-c++http://www.club.cc.cmu.edu/~ajo/docs/FAQ-acllc.html
> 
> Hi Jack,
> 
> I am one who loves to play around with soft-cores,
> yet I would also stay unless you have REAL valid reasons
> to use a soft-core do not go that path.
> I bet your EE guys can not give valid reasons
> (or that I would be able to invalidate their reasons)
> 
> 1) obsolete - dont fool your self, FPGA vendor soft-core do get
> obsoleted as well!
> 2) FPGA vendor soft-core is actually a client-trap vendor lock-in
> 
> now, Cortex-M3 RTL code is really beatiful, small and easy, basically
> you just
> select ITCM/DTCM sizes, number NVIC interrupts, and you are done
> and it useable on any FPGA with enough resources, so truly vendor
> independant
> 
> optionally there free Coldfire (original freescale) core available for
> Cyclone-3
> (for other FPGAs there is license fee)
> 
> Antti
> 
> 

Hi Antti,

Do you mean Cortex-M1?
(Cortex-M3 do not have TCM interface :-) )

Hi Jack,
Currently you can access Cortex-M1 with :
1) Actel
- Design using Libero and SoftConcole
- Library of AMBA components available
- Royality free
- Allow easy reuse of IP blocks with AMBA interface
Note: The early version of SoftConcole does not support TCM, please 
check with distributor to see if this has been improved.

2) Altera
Cortex-M1 Altera kit (contact Arrow Electronics)
- Design using SOPC builder
- Library of peripheral components available
- Free royal for 1000 units
(according to 
http://www.altera.com/products/ip/processors/32_16bit/m-arm-cortex-m1.html)
Note: Use Avalon interface with SOPC builder rather than AMBA

3) Synplicity used to have a program called ReadyIP.
Not sure if they are still doing it.

4) License it directly from ARM
- access to RTL so you can retarget to any FPGA
- include scripts for major FPGA tools and FPGA devices
- Use AMBA interface, and TCM support
- peripheral IP not included (you can possible find those in your FPGA 
development tools, on the Internet, books, or develop them on your own).

Hope this helps.
regards,
Joseph

On Nov 6, 1:53=A0pm, Joseph Yiu <joseph....@somewhereinarm.com> wrote:
> Antti wrote:
> > On Nov 6, 6:00 am, Jack Klein <jackkl...@spamcop.net> wrote:
> >> Parts obsolescence is biting again, and at least one of my EEs is
> >> insisting that we spin replacement boards with soft-core processors in
> >> FPGAs.
>
> >> There are several things I don't like about that.
>
> >> First, how robust are these systems. =A0What if power is lost during
> >> updating the configuration device?
>
> >> Second, I don't like the holy wars among our EEs. =A0Most of them use
> >> Altera and wouldn't touch Xilinx to save their lives. =A0But one guy
> >> uses only Xilinx and won't give the Altera rep the time of day. =A0Thi=
s
> >> hasn't bothered me up until now, when we put together a peripheral
> >> that is accessed to a microcontroller or DSP, because we define an
> >> interface and they meet it. =A0I don't need to care who the FPGA sourc=
e
> >> is.
>
> >> But if we're talking soft core, I'm not going to allow our embedded
> >> software department get saddled with supporting both NIOS and Micro
> >> Blaze.
>
> >> So third, I'd be grateful for any experiences with either soft core,
> >> or even better both, with a comparison between the two.
>
> >> And does anybody have any experience with the synthesizable ARM soft
> >> core for FPGA? =A0Unless there's a serious handicap, I'd prefer ARM if
> >> we do soft core, we've already good tools and programmer experience.
>
> >> Any and all comments, real or delusional, welcome.
>
> >> --
> >> Jack Kleinhttp://JK-Technology.Com
> >> FAQs for
> >> news:comp.lang.chttp://c-faq.com/
> >> news:comp.lang.c++http://www.parashift.com/c++-faq-lite/
> >> news:alt.comp.lang.learn.c-c++http://www.club.cc.cmu.edu/~ajo/docs/FAQ=
-acllc.html
>
> > Hi Jack,
>
> > I am one who loves to play around with soft-cores,
> > yet I would also stay unless you have REAL valid reasons
> > to use a soft-core do not go that path.
> > I bet your EE guys can not give valid reasons
> > (or that I would be able to invalidate their reasons)
>
> > 1) obsolete - dont fool your self, FPGA vendor soft-core do get
> > obsoleted as well!
> > 2) FPGA vendor soft-core is actually a client-trap vendor lock-in
>
> > now, Cortex-M3 RTL code is really beatiful, small and easy, basically
> > you just
> > select ITCM/DTCM sizes, number NVIC interrupts, and you are done
> > and it useable on any FPGA with enough resources, so truly vendor
> > independant
>
> > optionally there free Coldfire (original freescale) core available for
> > Cyclone-3
> > (for other FPGAs there is license fee)
>
> > Antti
>
> Hi Antti,
>
> Do you mean Cortex-M1?
> (Cortex-M3 do not have TCM interface :-) )
>
> Hi Jack,
> Currently you can access Cortex-M1 with :
> 1) Actel
> - Design using Libero and SoftConcole
> - Library of AMBA components available
> - Royality free
> - Allow easy reuse of IP blocks with AMBA interface
> Note: The early version of SoftConcole does not support TCM, please
> check with distributor to see if this has been improved.
>
> 2) Altera
> Cortex-M1 Altera kit (contact Arrow Electronics)
> - Design using SOPC builder
> - Library of peripheral components available
> - Free royal for 1000 units
> (according tohttp://www.altera.com/products/ip/processors/32_16bit/m-arm-=
cortex-m1...)
> Note: Use Avalon interface with SOPC builder rather than AMBA
>
> 3) Synplicity used to have a program called ReadyIP.
> Not sure if they are still doing it.
>
> 4) License it directly from ARM
> - access to RTL so you can retarget to any FPGA
> - include scripts for major FPGA tools and FPGA devices
> - Use AMBA interface, and TCM support
> - peripheral IP not included (you can possible find those in your FPGA
> development tools, on the Internet, books, or develop them on your own).
>
> Hope this helps.
> regards,
> Joseph

sorry, my mistake of course M1 :)
I have synthesized M3 for Xilinx too, but it far more larger and too
complicated (too much resources)

M1 however is real nice thing, real small too, in terms of FPGA
resources

Antti

Jack Klein skrev:
> Parts obsolescence is biting again, and at least one of my EEs is
> insisting that we spin replacement boards with soft-core processors in
> FPGAs.
> 
> There are several things I don't like about that.
> 
> First, how robust are these systems.  What if power is lost during
> updating the configuration device?
> 
> Second, I don't like the holy wars among our EEs.  Most of them use
> Altera and wouldn't touch Xilinx to save their lives.  But one guy
> uses only Xilinx and won't give the Altera rep the time of day.  This
> hasn't bothered me up until now, when we put together a peripheral
> that is accessed to a microcontroller or DSP, because we define an
> interface and they meet it.  I don't need to care who the FPGA source
> is.
> 
> But if we're talking soft core, I'm not going to allow our embedded
> software department get saddled with supporting both NIOS and Micro
> Blaze.

> So third, I'd be grateful for any experiences with either soft core,
> or even better both, with a comparison between the two.
> 
> And does anybody have any experience with the synthesizable ARM soft
> core for FPGA?  Unless there's a serious handicap, I'd prefer ARM if
> we do soft core, we've already good tools and programmer experience.
> 
> Any and all comments, real or delusional, welcome.
> 

Why not do a CPU module with a micro.
If the micro goes tits up, you are bound to find another.
and no need to redesign anything but the CPU module.

If you use external memory you may want to do this anyway to protect
against memory obsolecense.



Best Regards
Ulf Samuelsson

Jack Klein skrev:
> Parts obsolescence is biting again, and at least one of my EEs is
> insisting that we spin replacement boards with soft-core processors in
> FPGAs.
> 
> There are several things I don't like about that.
> 
> First, how robust are these systems.  What if power is lost during
> updating the configuration device?
> 
> Second, I don't like the holy wars among our EEs.  Most of them use
> Altera and wouldn't touch Xilinx to save their lives.  But one guy
> uses only Xilinx and won't give the Altera rep the time of day.  This
> hasn't bothered me up until now, when we put together a peripheral
> that is accessed to a microcontroller or DSP, because we define an
> interface and they meet it.  I don't need to care who the FPGA source
> is.
> 
> But if we're talking soft core, I'm not going to allow our embedded
> software department get saddled with supporting both NIOS and Micro
> Blaze.

> So third, I'd be grateful for any experiences with either soft core,
> or even better both, with a comparison between the two.
> 
> And does anybody have any experience with the synthesizable ARM soft
> core for FPGA?  Unless there's a serious handicap, I'd prefer ARM if
> we do soft core, we've already good tools and programmer experience.
> 
> Any and all comments, real or delusional, welcome.
> 

Why not do a CPU module with a micro.
If the micro goes tits up, you are bound to find another.
and no need to redesign anything but the CPU module.

If you use external memory you may want to do this anyway to protect
against memory obsolecense.



Best Regards
Ulf Samuelsson

> So third, I'd be grateful for any experiences with either soft core,
> or even better both, with a comparison between the two.

[Warning: my company sells tools.]

Our latest RapidiTTy FPGA tools target both Xilinx and Altera FPGAs
(others in the pipeline).  You can migrate between targets with a
couple of mouse clicks.

The tools have a fully-integrated soft core with a cost-effective
licencing model.

Michael Pont
www.tte-systems.com/products/fpga

Jack Klein schrieb:

> But if we're talking soft core, I'm not going to allow our embedded
> software department get saddled with supporting both NIOS and Micro
> Blaze.

Why go for a non-free softcore? There's lots of free softcores out
there, many of them with good toolchain support (typically gcc), like
OpenRISC or Leon (SPARC compatible).

Philipp