Recommendation aksed for embedded processor

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I am looking for a processor/controller to be used in an embedded
system that offers the following:

- low costs (if possible < 30 $ @ 10k)
- stable and well-supported platform
- PCI integrated (33MHz/32bit, no PCI-X, maybe PCIe could be
interesting if it is already available as integrated peripheral)
- Gigabit LAN integrated (option: could be done via PCI with special
IC, but then it has to be included in the costs)
- support of linux (preferrably "standard" linux)
- at least 300MHz CPU clock, better more for performance reasons (may
depend on actual architecture)

Nice to have, but not crucial:
- USB 2.0 integrated (option: could be done via PCI with special IC,
but then it has to be included in the costs)
- hardware accelerated encryption
- hardware accelerated network operations, e.g. for TCP/IP etc.

On first view the Intel network processors looked interesting, but they
offer only 100Mb LAN (and most of them exceed the price limit
anyway...).

Any hints where to look are appreciated.

Matthias


Re: Recommendation aksed for embedded processor

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Difficult to do for the following reasons.

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To support Gigabit, you probably need 64 bits PCI and faster than
300MHz CPU.
You also needs lots of RAM buffers, and things gets expensive beyond
64M.
What wrong with 100M plus a switch?

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Re: Recommendation aksed for embedded processor

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Just to clarify: This amount is meant only for the processor, all other
things have an extra budget. But still, it is a tough constraint...
If there processors matching my wish list but costing something above
30$ then I would like to learn about them, too.


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Regarding PCI we have to assume that PCI 33MHz/32bit is sufficient,
since we do not need to transmit continously 1 Gbps, but the device
will experience periods where it has to transmit say 150-200 Mbps for
several minutes. Most of the time the data rate will be even below
100Mbps.
On the other hand, if the Gb-LAN interface would be an integrated
peripheral of the processor then the (external) PCI bus would not have
to carry the network load.

Regarding CPU I agree. 300MHz seems to be the absolute lower limit
assuming a powerful processor architecture, but more realistic are >=
500MHz.


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Sometimes we need data rates above 100 Mbps directly from the
processor.

Any hints where to look are appreciated.
 
Matthias


Re: Recommendation aksed for embedded processor

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What about multiple 100M links ? There are quite a few 32-bit
processors with 4x embedded 100M ethernet interfaces. Used in
cheap switches AFAIK.

Regards
  Anton Erasmus


Re: Recommendation aksed for embedded processor
I am not sure about the price, but what you describe will
be covered by one of the Freescale PPC based devices.
Have a look at the 8548 (I believe fastest) or the 5200 (only
10/100 Ethernet, though, but has PCI 32/66).
 You will probably be able to find some Linux for those,
and before too long I'll probably release a fullblown DPS
for the 5200.

Dimiter

------------------------------------------------------
Dimiter Popoff               Transgalactic Instruments

http://www.tgi-sci.com
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Re: Recommendation aksed for embedded processor

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Thanks; I had a look on the Freescales devices and found some very
interesting ones. Although they exceed the original price limit they
will be taken into consideration since they offer features that may
reduce the total chip count significantly.

Particularly the MPC8349E is attracting me (seems to be around 60$, but
I do not have accurate prices yet). Any comments on that one?

Regards,
Matthias


Re: Recommendation aksed for embedded processor
Hi Matthias,

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looks good to me. The core is 603e compatible, this gives you the
standard FPU etc., and the first DPS I am likely to release for
outside-tgi use will be based exactly on it.

Apart from the 1mm pitched BGA which will be a tough route (perhaps
impossible on only two signal layers), I see nothing scary.

Dimiter

------------------------------------------------------
Dimiter Popoff               Transgalactic Instruments

http://www.tgi-sci.com
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Re: Recommendation aksed for embedded processor

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This cost around the same as the GX2/5536 pair, and similiar
complexity.

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It's possible, but expensive for 2 signals + 2 planes.   You would need
0.4 pad, 0.2 holes and 0.2 spacing.   We just got a batch of such
boards, with 30% failure (not passing the board testing) at the
factory.

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Re: Recommendation aksed for embedded processor


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How many traces do you manage between the BGA pads?
With the 1.27 pitched BGAs, I manage 3 traces and this
is enough. At 0.4 pads, do they drill 0.2 through them?
I doubt 3 traces will be doable, this would take 3.3 mil (0.086mm)
design rules, those I have worked with do not want to hear
about anything below 4 mils. I am not sure a big BGA
will be routable with only 2 traces between the pads...
 Please give some more details, I am curious.

Dimiter

------------------------------------------------------
Dimiter Popoff               Transgalactic Instruments

http://www.tgi-sci.com
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Re: Recommendation aksed for embedded processor
Reposted due to google error.  Google's reliablities is inversely
proportional to it's stock price.  I am looking to switch
newsgroup server.  Sorry about all the food references.  I must
be hungry.

Didi wrote:
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2 traces with reduced width between pads.

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No, they drilled standard off-pad via, so called dog-bone pad.
Although we looked hard at plugged BGA pad, we chickened
out at the end.  We might try to experiment more before doing
that in production.   With plugged BGA pad, it might be possible
to go below 1mm (more layers, without trace between pads) for
smaller holes or bigger holes for lower cost.

For the plugged BGA pad, we made some donut PCB prototype and
filled them with high temperature solder.  We then layered a
low temperature solder balls on top.  Finally, we mounted the BGA
(more like ball on ball, instead of ball on pad) and reflow
with low temperature.

The low temperature solder is expensive (silver) and we need a
better alignment process for ball on ball.  So, we need more
testing before putting them in productions.

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I agree.  Finer pitch designs are more expensive than more layers.

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Re: Recommendation aksed for embedded processor

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May I suggest the AMD Geode GX2/CS5536 (533 MHz), for $40 @1K.  $30
@10K is possible, if we buy together.  We only need a few hundred of
them.  We are using RTL8100 (100M, 100 QFP), but you can use RTL8169
(1G, 128 QFP).

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Works with Linux 2.2 and 2.4, but have not try 2.6 yet.  Works with Dos
and Window 98 (customer requirement, don't ask why), have not try XP
yet.

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Yes for PCI.

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RTL8169 is possible.

Other features: VGA and LCD, USB 2.0, 64 bits DDR SDRAM, less than 10W
total power.

Major drawback: no CPU cache and lower CPU performance.


Re: Recommendation aksed for embedded processor

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Thanks for your reply. Since we are trying to reduce the number of
"complex" chips this approach does not exactly fit. Also, the
performance may be an issue, then.

Nevertheless, this information is appreciated as well, since it helps
in decision finding.

So it seems that I will have a closer look on the Freescale devices...

Regards,
Matthias


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