On Tue, 08 Apr 2008 08:41:53 -0700, the renowned John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:
>(also posted to s.e.d.)
>
>
>We're considering a new product, a spectroscopy controller, that would
>need a fair hunk of data-moving power and gigabit Ethernet capability
>to talk to a host system. We would center it on a largish FPGA that
>would run the actual physics, but we still need supervision,
>self-test, local maintanance capability (maybe just RS-232) and the
>Ethernet stuff. Possibilities include...
>
>1. Do everything in the FPGA. Possible but nasty.
>
>2. Use a cpu chip on the main board, next to the FPGA. Both powerQuicc
>and Blackfin chips have the horsepower and include the gbit PHY. Both
>run uC Linux.
>
>3. Use an embedded board-level PC,
>
> 3a PC/104+. Expensive.
>
> 3b Some small-form-factor "regular" pc motherboard. Cheap.
>
>both 3's would probably use the PCI bus to talk to the FPGA.
>
>
>Economically, and for speedy development, 3b sounds best. Has anybody
>done things like this with one of the tiny PC motherboards? Can you
>recommend a form-factor and a vendor? We'd need gbit Ethernet and a
>free PCI slot to interface to the process. We could maybe live with
>100M Ethernet if we were confident that an upgrade would be available
>in a year or two.
>
>The thing that scares me about using an embedded PC is that the
>product lifetimes tend to be short.
>
>John
Have you considered Micro ATX?
Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com
Reply by Guy Macon●April 9, 20082008-04-09
John Larkin wrote:
>Do PC104 boards have long lifetimes? The CPU and support chips sure
>come and go fast.
I have found that they end to buy large quantities of the chips
around the time they are discontinued, and thus are able to keep
the same design in production for a long time.
--
misc.business.product-dev: a Usenet newsgroup
about the Business of Product Development.
-- Guy Macon <http://www.guymacon.com/>
Reply by Guy Macon●April 9, 20082008-04-09
Tim Wescott wrote:
>
>John Larkin wrote:
>
>> We're considering a new product, a spectroscopy controller, that would
>> need a fair hunk of data-moving power and gigabit Ethernet capability to
>> talk to a host system. We would center it on a largish FPGA that would
>> run the actual physics, but we still need supervision, self-test, local
>> maintanance capability (maybe just RS-232) and the Ethernet stuff.
>> Possibilities include...
>>
>> 1. Do everything in the FPGA. Possible but nasty.
>>
>> 2. Use a cpu chip on the main board, next to the FPGA. Both powerQuicc
>> and Blackfin chips have the horsepower and include the gbit PHY. Both
>> run uC Linux.
>>
>> 3. Use an embedded board-level PC,
>>
>> 3a PC/104+. Expensive.
>>
>> 3b Some small-form-factor "regular" pc motherboard. Cheap.
>>
>> both 3's would probably use the PCI bus to talk to the FPGA.
>>
>>
>> Economically, and for speedy development, 3b sounds best. Has anybody
>> done things like this with one of the tiny PC motherboards? Can you
>> recommend a form-factor and a vendor? We'd need gbit Ethernet and a free
>> PCI slot to interface to the process. We could maybe live with 100M
>> Ethernet if we were confident that an upgrade would be available in a
>> year or two.
>>
>> The thing that scares me about using an embedded PC is that the product
>> lifetimes tend to be short.
>
>I've said it here other times: if you're building 100/year to build
>something and you can save $50000 engineering time buying instead of
>engineering, then $500/ea is a good price.
>
>If you have the luxury of having application requirements that are not
>terrifically real time, if you have a big, square space for your boards,
>and if engineering time is a big part of the system end cost, then a PC-
>derived part is the way to go. If you have a long product life, then why
>not PC-104? If your volumes are low then an inexpensive motherboard
>could get very expensive the first time you have to swap it out (in a
>hurry because Purchasing didn't see it coming).
> (also posted to s.e.d.)
>
>
> We're considering a new product, a spectroscopy controller, that would
> need a fair hunk of data-moving power and gigabit Ethernet capability
> to talk to a host system. We would center it on a largish FPGA that
> would run the actual physics, but we still need supervision,
> self-test, local maintanance capability (maybe just RS-232) and the
> Ethernet stuff. Possibilities include...
>
> 1. Do everything in the FPGA. Possible but nasty.
Not necessarily bad. Have you looked into using one of the embedded
processors? The Altera Nios or Xilinx MicroBlaze "soft" cores can be
programmed into general logic. Xilinx also has FPGA's with embedded
"hard" PowerPC processors.
I've only used the Nios for a small project, but I found it easy and
convenient to use (programmed using C code). The soft processors are
like micrcontrollers. Great for easy stuff like self-test, etc. They
also have a lot of optional peripherals that can be added on. I've also
heard good things about the Xilinx PowerPC option from my coworkers if
you need to do more serious processing.
Derek
Reply by Ed Prochak●April 8, 20082008-04-08
On Apr 8, 11:41 am, John Larkin
<jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
> (also posted to s.e.d.)
>
> We're considering a new product, a spectroscopy controller, that would
> need a fair hunk of data-moving power and gigabit Ethernet capability
> to talk to a host system. We would center it on a largish FPGA that
> would run the actual physics, but we still need supervision,
> self-test, local maintanance capability (maybe just RS-232) and the
> Ethernet stuff. Possibilities include...
>
> 1. Do everything in the FPGA. Possible but nasty.
>
> 2. Use a cpu chip on the main board, next to the FPGA. Both powerQuicc
> and Blackfin chips have the horsepower and include the gbit PHY. Both
> run uC Linux.
>
> 3. Use an embedded board-level PC,
>
> 3a PC/104+. Expensive.
>
> 3b Some small-form-factor "regular" pc motherboard. Cheap.
>
> both 3's would probably use the PCI bus to talk to the FPGA.
>
> Economically, and for speedy development, 3b sounds best. Has anybody
> done things like this with one of the tiny PC motherboards? Can you
> recommend a form-factor and a vendor? We'd need gbit Ethernet and a
> free PCI slot to interface to the process. We could maybe live with
> 100M Ethernet if we were confident that an upgrade would be available
> in a year or two.
>
> The thing that scares me about using an embedded PC is that the
> product lifetimes tend to be short.
>
> John
I have no detailed suggestions, but am bidding on a similar project.
Drop me a line and we can compare notes off-line. As things progress
maybe we can present our final choices and why. (non-disclosure
prevents me from saying more right now.)
Ed
--
Magic Interface, Ltd.
www.magicinterface.com
440-498-3700
Hardware/Software Alchemy
Reply by ●April 8, 20082008-04-08
On Apr 8, 12:46 pm, Vladimir Vassilevsky <antispam_bo...@hotmail.com>
wrote:
> As for uClinux, I stay away from it.
There are of course many factors that go into any choice.
One argument for this application that might be in favor of uClinux
however is
the relative ease of porting the application to a new computing
platform should
that become necessary. Certainly when you use on-chip peripherals you
invest in an architecture, but there's no external vendor-lock in that
prevents
you from writing new drivers to adapt to the peripherals of a
different processor.
Leaving the low level drivers aside, you can of course achieve some of
this
flexibility be writing your application program in a way that is not
platform or
operating system dependent.
Reply by Vladimir Vassilevsky●April 8, 20082008-04-08
John Larkin wrote:
> We're considering a new product, a spectroscopy controller, that would
> need a fair hunk of data-moving power and gigabit Ethernet capability
> to talk to a host system. We would center it on a largish FPGA that
> would run the actual physics, but we still need supervision,
> self-test, local maintanance capability (maybe just RS-232) and the
> Ethernet stuff. Possibilities include...
>
> 1. Do everything in the FPGA. Possible but nasty.
>
> 2. Use a cpu chip on the main board, next to the FPGA. Both powerQuicc
> and Blackfin chips have the horsepower and include the gbit PHY. Both
> run uC Linux.
BlackFin has MAC only (needs external PHY), and can run only 100M
ethernet. As for uClinux, I stay away from it.
>
> 3. Use an embedded board-level PC,
>
> 3a PC/104+. Expensive.
>
> 3b Some small-form-factor "regular" pc motherboard. Cheap.
>
> both 3's would probably use the PCI bus to talk to the FPGA.
4. Make a PC of your own with all of the necessary stuff on the board. I
know some people who make the embedded PCs customised for the particular
applications.
>
>
> Economically, and for speedy development, 3b sounds best. Has anybody
> done things like this with one of the tiny PC motherboards? Can you
> recommend a form-factor and a vendor? We'd need gbit Ethernet and a
> free PCI slot to interface to the process. We could maybe live with
> 100M Ethernet if we were confident that an upgrade would be available
> in a year or two.
>
> The thing that scares me about using an embedded PC is that the
> product lifetimes tend to be short.
In the addition to the problems you mentioned, there could be the very
unexpected hardware and driver issues when they change the revision of
the mother board.
Vladimir Vassilevsky
DSP and Mixed Signal Design Consultant
http://www.abvolt.com
Reply by larwe●April 8, 20082008-04-08
On Apr 8, 12:06 pm, John Larkin
<jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
> Do PC104 boards have long lifetimes? The CPU and support chips sure
> come and go fast.
You should talk to the suppliers about EOL plans for the boards in
question. My experience has been that these SBCs have very long
lifetimes vis-a-vis COTS mobos; typically six to ten years vs 12-18
months max for a COTS board. One of the reasons SBCs are much more
expensive than comparable COTS motherboards is because the mfrs will
buy and hold stock of the critical components. (Or at least so the
Advantech rep told me). Certainly boards I was buying five and six
years ago are still available today.
> PC104 has mechanical advantages; it would just plug onto our main
> application board. But they are expensive.
I am 350% in agreement with Tim that this application sounds like a
candidate for a PC architecture. It's not absolutely clear to me how
the cost-benefit of a COTS mobo vs PC104 will break down for your
specific application, though. However I would say that you'll be
enduring mobo changes 3~5x more frequently with the COTS path. Whether
these ongoing eng costs are worth it to you depends on how difficult
it is to qualify a new mobo. My instinct would be to say "buy as much
time between profitless sustaining-engineering efforts as possible".
I'm sure your product is not something I'm going to see for $39.95 at
Wal-Mart.
Reply by John Larkin●April 8, 20082008-04-08
On Tue, 08 Apr 2008 10:50:51 -0500, Tim Wescott <tim@seemywebsite.com>
wrote:
>On Tue, 08 Apr 2008 08:41:53 -0700, John Larkin wrote:
>
>> (also posted to s.e.d.)
>>
>>
>> We're considering a new product, a spectroscopy controller, that would
>> need a fair hunk of data-moving power and gigabit Ethernet capability to
>> talk to a host system. We would center it on a largish FPGA that would
>> run the actual physics, but we still need supervision, self-test, local
>> maintanance capability (maybe just RS-232) and the Ethernet stuff.
>> Possibilities include...
>>
>> 1. Do everything in the FPGA. Possible but nasty.
>>
>> 2. Use a cpu chip on the main board, next to the FPGA. Both powerQuicc
>> and Blackfin chips have the horsepower and include the gbit PHY. Both
>> run uC Linux.
>>
>> 3. Use an embedded board-level PC,
>>
>> 3a PC/104+. Expensive.
>>
>> 3b Some small-form-factor "regular" pc motherboard. Cheap.
>>
>> both 3's would probably use the PCI bus to talk to the FPGA.
>>
>>
>> Economically, and for speedy development, 3b sounds best. Has anybody
>> done things like this with one of the tiny PC motherboards? Can you
>> recommend a form-factor and a vendor? We'd need gbit Ethernet and a free
>> PCI slot to interface to the process. We could maybe live with 100M
>> Ethernet if we were confident that an upgrade would be available in a
>> year or two.
>>
>> The thing that scares me about using an embedded PC is that the product
>> lifetimes tend to be short.
>>
>> John
>
>I've said it here other times: if you're building 100/year to build
>something and you can save $50000 engineering time buying instead of
>engineering, then $500/ea is a good price.
And $79 is a better price!
>
>If you have the luxury of having application requirements that are not
>terrifically real time, if you have a big, square space for your boards,
>and if engineering time is a big part of the system end cost, then a PC-
>derived part is the way to go. If you have a long product life, then why
>not PC-104? If your volumes are low then an inexpensive motherboard
>could get very expensive the first time you have to swap it out (in a
>hurry because Purchasing didn't see it coming).
Do PC104 boards have long lifetimes? The CPU and support chips sure
come and go fast.
At roughly $100 a pop, we could keep 100 or so motherboards in stock,
so at least a discontinuance or change wouldn't sneak up on us
unexpected.
PC104 has mechanical advantages; it would just plug onto our main
application board. But they are expensive.
John
Reply by Tim Wescott●April 8, 20082008-04-08
On Tue, 08 Apr 2008 08:41:53 -0700, John Larkin wrote:
> (also posted to s.e.d.)
>
>
> We're considering a new product, a spectroscopy controller, that would
> need a fair hunk of data-moving power and gigabit Ethernet capability to
> talk to a host system. We would center it on a largish FPGA that would
> run the actual physics, but we still need supervision, self-test, local
> maintanance capability (maybe just RS-232) and the Ethernet stuff.
> Possibilities include...
>
> 1. Do everything in the FPGA. Possible but nasty.
>
> 2. Use a cpu chip on the main board, next to the FPGA. Both powerQuicc
> and Blackfin chips have the horsepower and include the gbit PHY. Both
> run uC Linux.
>
> 3. Use an embedded board-level PC,
>
> 3a PC/104+. Expensive.
>
> 3b Some small-form-factor "regular" pc motherboard. Cheap.
>
> both 3's would probably use the PCI bus to talk to the FPGA.
>
>
> Economically, and for speedy development, 3b sounds best. Has anybody
> done things like this with one of the tiny PC motherboards? Can you
> recommend a form-factor and a vendor? We'd need gbit Ethernet and a free
> PCI slot to interface to the process. We could maybe live with 100M
> Ethernet if we were confident that an upgrade would be available in a
> year or two.
>
> The thing that scares me about using an embedded PC is that the product
> lifetimes tend to be short.
>
> John
I've said it here other times: if you're building 100/year to build
something and you can save $50000 engineering time buying instead of
engineering, then $500/ea is a good price.
If you have the luxury of having application requirements that are not
terrifically real time, if you have a big, square space for your boards,
and if engineering time is a big part of the system end cost, then a PC-
derived part is the way to go. If you have a long product life, then why
not PC-104? If your volumes are low then an inexpensive motherboard
could get very expensive the first time you have to swap it out (in a
hurry because Purchasing didn't see it coming).
--
Tim Wescott
Control systems and communications consulting
http://www.wescottdesign.com
Need to learn how to apply control theory in your embedded system?
"Applied Control Theory for Embedded Systems" by Tim Wescott
Elsevier/Newnes, http://www.wescottdesign.com/actfes/actfes.html