We’re working on an open-source WiMAX receiver/scanner and we’re
looking into using a high-performance DSP to process data from USRP.
Right now we implement this processing in FPGA, but we want to
experiment with DSPs too. I know there are skilled people here and I’m
looking forward to hear their opinion.
Note, that this project is not meant for starving students or
occasional hobbyists. It is for high-profile hobbyists, targeted
researchers and for small companies. So please refrain from comments
like “no way, this is too expensive for 90% of community”. Though we
would appreciate comments on how to make it cheaper.
So, I’m looking for the community advise about pros and cons of
different DSPs. Particularly I’m interested in comparing Freescale
MSC815x/MSC825x [1][2][3] and TI TMS320C667x [4][5] DSPs/SoCs from the
perspective of open-source development. But if you know any other good
high-profile DSPs - please propose them too. So far, as I read it we
have following comparison:
Price.
It used to be that Freescale is cheaper, but right now I see that
“pricing for the MSC8156 starts at $192 in 10,000 unit quantities”
[6], while TMX320C6670CYP is priced 160.00 USD | 1ku [7]. So they’re
barely the same with TI slightly winning. I’m not sure how much will
new MSC8157 cost.
Development tools price
Both Freescale CodeWarrior and TI Code Composer seem to be at the same
line with about $2K per single license (correct me if I’m wrong - I
may have missed something easily).
Big minus here is that neither Freescale nor TI offer open/free
compilers for their DSPs, which is a big roadblock for open-source
development.
Support for open-source technologies.
Well, both Freescale and TI declare themselves as more or less
open-source supporters (which is weird while they have expensive
development tools). Both offers BSPs for Linux for GPP part of SoCs
and free/open OSes for DSP cores (SmartDSP for Freescale, SYS/BIOS for
TI). I would appreciate if someone could comment on maturity of those
and their usability (bug-ness level).
Other then that I don’t see any evidence of their support for
open-source for their DSPs.
Quality/simplicity
I have no experience with those DSPs yet, so I would very much
appreciate comments about development tools quality / easy to use,
code generation quality, DSP architecture simplicity for a programmer
and (important!) documentation quality.
Chips availability
I’m a software guy, so again I seek for an insight about availability
of Freescale and TI DSPs. How hard is it to source them? Especially
outside of US?
Any other concerns?
Please share your opinion - I should have missed something important.
It’s hard to keep everything in mind.
PS As I told, we’re working on an open-source WiMAX receiver right
now. If you’re a skilled engineer and you’re willing to participate -
drop me a few lines with your experience description. We need more
skilled hands to get up and running faster. And I should say this
project is a lot of fun.
PPS Please don’t mail me if you just want to look into the code out of
curiosity or don’t have enough skills or enough time to help. We’ll
announce the project publicly when we have a (somehow) working
prototype. Right now we just have a bunch of Matlab proof-of-concept
code and we’ve started to port it to FPGA.
Thank you if you get that far! Sorry for the long e-mail
On Fri, Jan 28, 2011 at 10:14 AM, Alexander C. [email protected] wrote:
Development tools price
Both Freescale CodeWarrior and TI Code Composer seem to be at the same
line with about $2K per single license (correct me if I’m wrong - I
may have missed something easily).
Big minus here is that neither Freescale nor TI offer open/free
compilers for their DSPs, which is a big roadblock for open-source
development.
TI has a “free” download of their DSP compiler. Information can be
found here:
2- TI actually offers all the tools you need to develop for their DSP
for free, I can vouch for the C64x+ DSP since that’s what I have
experience using. You can download and look at the supported DSP for
the free download from http://software-dl.ti.com/dsps/dsps_registered_sw/sdo_sb/targetcontent/
The biggest issue you might run into with the free software is the
ability to use a JTAG, if you want to use a JTAG you have to use Code
Composer period. Though I’ve read about people using the free demo
version of Code Composer (CCS) 4.0 with a very cheap JTAG ( < $150) to
debug their DSP code. I think TI restricts the type of DSPs and JTAGs
you can use with the free CCS I know that the JTAG I use (XDS560) is not
supported.
3- TI support for open source is surprisingly decent. I’ve posted many
questions on their support forums and TI engineers have always gotten
back to me with alot of good information and continued asnwering as
posted more follow up questions.
4- The learning tool has a bit of a learning curve that’s for sure. I
have posted a github link on the listserv yesterday which includes new
custom blocks for GNU Radio using the C64x+ DSP. You might find the
guide helpful in shedding some light about developing with TI tools.
6- I’ve been using TI software as an open source developer for almost
1.5 years now and I think they’ve managed to find a great balance
between being a for profit company and a supplier of tools for the open
source community. I don’t have experience with freescale but my
experience with TI has been a positive one.
Hi Jeff: interesting reply. I remember when TI and MOT did exactly the
opposite. TI had the 9900 processor series that was much better than
anything on the market, and essentially blew it off. MOT had the
6800/68000 series, that became moderately successful. The most crippled
processor of the time, the Intel, won the day. Now the TI processors
thrive, MOT is in the dumper, and Intel is king of the heap. A real riot
to watch history as it happens, huh? Think also of the lovely alpha
chip,
and the downfall of mighty DEC. sigh.
Don
–
“Neither the voice of authority nor the weight of reason and argument
are
as significant as experiment, for thence comes quiet to the mind.”
R. Bacon
“If you don’t know what it is, don’t poke it.”
Ghost in the Shell
Hi Jeff: interesting reply. I remember when TI and MOT did exactly the
opposite. TI had the 9900 processor series that was much better than
anything on the market, and essentially blew it off. MOT had the
6800/68000 series, that became moderately successful. The most crippled
processor of the time, the Intel, won the day. Now the TI processors
thrive, MOT is in the dumper, and Intel is king of the heap. A real riot
to watch history as it happens, huh? Think also of the lovely alpha chip,
and the downfall of mighty DEC. sigh.
Yes things look much different years after the heat of the battle.
Clarity is gained in small increments.
I know some of the TI execs from the early 1980s (in fact one works with
me, he was Gen Mgr of Consumer Products at
the time). The general conclusion is that TI guys learned a hard lesson
with the 9900 and applied it well over time.
They never ventured forth again without solid development tools and
other supporting software. But on the other hand
they took nearly 10 years to support Linux after major players started
embracing it… oh well.
you can use with the free CCS I know that the JTAG I use (XDS560) is not
supported.
find a great balance between being a for profit company and a supplier of tools
for the open source community. I
don’t have experience with freescale but my experience with TI has been a
positive one.
We are a heavy TI device user and have been for years. Al Fayez’s
comments are pretty much accurate.
I would add a few additional comments for MSC8x5x vs. C667x; i.e. high
performance multicore CPUs (the vendors are
moving away from the term “DSPs” nowadays, hehe). My comments apply only to these high-end multicore devices.
My two major concerns with Freescale are a) peer support and b) product
roadmap. First, there simply are not enough
users. For example there is a motoroladsp Yahoo Group (there are
several TI DSP Yahoo groups, C6x, C5x, etc) but in
the last several years activity on the mot group has slowly died off.
There are still knowledgeable Mot/Freescale DSP
guys on comp.dsp, but mostly in audio/acoustic related areas.
Second, product roadmap. Before they were Freescale, Mot used to have a
strong, competitive product portfolio in DSP.
In 1998 they started a downhill slide when their CEO re-organized his
own DSP guys into an “internal resource
matrix”, essentially deciding there wasn’t actually a DSP market.
Obviously TI thought otherwise and became “a DSP
company” and we all know the rest of that story. (As a side note, that
CEO was Hector Ruiz, the same guy who later
presided over AMD during its decline and is now subject to an SEC
investigation). In 2004, Mot DSPs became Freescale
and enjoyed a resurgence with Starcore based devices. Starcore
technology has always looked quite promising, but in
my opinion, in day-to-day execution Freescale has not been able to match
TI. Now TI has out the C667x series, which
leaps beyond MSC815x/MSC825x.
Not to mention that TI’s multicore CPUs benefit indirectly, both in
terms of technical advances, and in terms of
customer support, from what TI is doing in smart phones, tablets,
high-performance ARM, etc.
Depends whe you want to start… C66 is there but just try to buy it if
you can. It is very much alike the qonverge from Freescale.
8156 won in 2009, 9 out of the 10 major customers in baseband and it is
still the best to go with right now due to Maple B accelerator.
CodeWarior comes with SDOS where you have all the drivers and demos for
MAPLE and all the periferals, you just have to copy paste some staff
from there. The good part is that you don’t have to write the code for
the kernels , it is in hardware and it is significantly quicker…
When it comes to roadmap… Freescale has a clear advantage,it builds DSP
specific for light radio, so you will see on the same SOC DSP+Power,
practically a basestation on Soc. TI can not do this since it has no
power architecture…
TI C66 based architectures are good , but they have 2-3 big minus
points:
No hardware accelerators for LTE, WiMax, WCDMA. So probably one needs
more cores
Future architectures will not have power for trafic and upper layer
code
Power consumtion of hybrid solutions is much better, and also it
gives a better area utilization.
Floating point units are good but 80-90% of the code does not need
such things…
So, I took my time to investigate TI offer further and after all I
should agree that TI support of open-source is indeed much more decent
then that of Freescale. Combined with Jeff’s comment about the number
of developers who work with TI and with Freescale, this moves TI far
behind Freescale. So, we decided to bet on TI for our open-source
development.
Now I can’t wait to get an EMV for this great new C66 SoC to start
playing.
And in my dreams I see someone creating a “Gumstix C66 4-8 core” to
use with USRP E100 - that would be truly killer SDR solution.
you have to use Code Composer period. Though I’ve read about people using the
free demo version of Code Composer
users. For example there is a motoroladsp Yahoo Group (there are several TI DSP
Yahoo groups, C6x, C5x, etc) but in
leaps beyond MSC815x/MSC825x.
Subject: [Discuss-gnuradio] TI vs Freescale DSP for open-source development
Note, that this project is not meant for starving students or
have following comparison:
line with about $2K per single license (correct me if I’m wrong - I
and free/open OSes for DSP cores (SmartDSP for Freescale, SYS/BIOS for
and (important!) documentation quality.
PS As I told, we’re working on an open-source WiMAX receiver right
Thank you if you get that far! Sorry for the long e-mail
Regards,
