Low Cost arm chips to offload TCP/IP stacks

Hi All,

I am considering an application with Spartan-3 FPGAs.  I need to run
TCP/IP and a few other networking applications along with other user
logic.  The trade-off that I am considering is -

Microblaze inside the FPGA costs about 2000LCs.  I am considering I
may be able to a lot more with those 2000LCs if I put an external ARM
processor instead.  I am wondering if there exists a no-frills ARM
chip out there that would cost me a buck or two, then I may be able to
get more out of those 2000LCs.  Is there a chip out there?

TIA
Sanjay

On Sat, 31 May 2008 20:23:16 -0700 (PDT), parekh.sh@gmail.com wrote:

>Hi All,
>
>I am considering an application with Spartan-3 FPGAs.  I need to run
>TCP/IP and a few other networking applications along with other user
>logic.  The trade-off that I am considering is -
>
>Microblaze inside the FPGA costs about 2000LCs.  I am considering I
>may be able to a lot more with those 2000LCs if I put an external ARM
>processor instead.  I am wondering if there exists a no-frills ARM
>chip out there that would cost me a buck or two, then I may be able to
>get more out of those 2000LCs.  Is there a chip out there?
>
>TIA
>Sanjay

NXP LPC210x series are very cheap - ought to be able to do TCP/IP etc. 

<parekh.sh@gmail.com> wrote in message 
news:2829dd7c-841a-433b-906b-449e62e631f2@s21g2000prm.googlegroups.com...
> Hi All,
>
> I am considering an application with Spartan-3 FPGAs.  I need to run
> TCP/IP and a few other networking applications along with other user
> logic.  The trade-off that I am considering is -
>
> Microblaze inside the FPGA costs about 2000LCs.  I am considering I
> may be able to a lot more with those 2000LCs if I put an external ARM
> processor instead.  I am wondering if there exists a no-frills ARM
> chip out there that would cost me a buck or two, then I may be able to
> get more out of those 2000LCs.  Is there a chip out there?
>
> TIA
> Sanjay


Something like:

SAM7X (integrated MAC)
LM3S6965 (integrated MAC and PHY)
LPC2368 (integrated MAC)
etc.

...but if all you want is TCP/IP then there are probably lower cost 
solutions outside of ARM, like Cygnal, Zilog, Microchip etc. that come with 
examples.

--
Regards,
Richard.

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parekh.sh@gmail.com wrote:
> I am considering an application with Spartan-3 FPGAs.  I need to run
> TCP/IP and a few other networking applications along with other user
> logic.  The trade-off that I am considering is -
> 
> Microblaze inside the FPGA costs about 2000LCs.  I am considering I
> may be able to a lot more with those 2000LCs if I put an external ARM
> processor instead.  I am wondering if there exists a no-frills ARM
> chip out there that would cost me a buck or two, then I may be able to
> get more out of those 2000LCs.  Is there a chip out there?

If you want a prepackaged hardware+software solution -- just needs
magnetics on one side, provides a "socket" interface on the other
(parallel or SPI) -- check out the WIZnet products:

    http://www.wiznet.co.kr/

Not the cheapest solution out there, but could really save you a lot
of development time.

-- Dave Tweed

On Jun 1, 2:58 am, Mike Harrison <m...@whitewing.co.uk> wrote:
> On Sat, 31 May 2008 20:23:16 -0700 (PDT), parekh...@gmail.com wrote:
> >Hi All,
>
> >I am considering an application with Spartan-3 FPGAs.  I need to run
> >TCP/IP and a few other networking applications along with other user
> >logic.  The trade-off that I am considering is -
>
> >Microblaze inside the FPGA costs about 2000LCs.  I am considering I
> >may be able to a lot more with those 2000LCs if I put an external ARM
> >processor instead.  I am wondering if there exists a no-frills ARM
> >chip out there that would cost me a buck or two, then I may be able to
> >get more out of those 2000LCs.  Is there a chip out there?
>
> >TIA
> >Sanjay
>
> NXP LPC210x series are very cheap - ought to be able to do TCP/IP etc.

Thanks.  I see on their block diagram that the AHB does not get driven
out.  Instead, the VPB what seems like a peripheral bus.  I wonder
what kind of performance I can get from this bus.
-sanjay

On Sun, 1 Jun 2008 08:47:58 -0700 (PDT), parekh.sh@gmail.com wrote:

>Thanks.  I see on their block diagram that the AHB does not get driven
>out.  Instead, the VPB what seems like a peripheral bus.  I wonder
>what kind of performance I can get from this bus.
>-sanjay

We have run our Powernet stack
  http://www.mpeforth.com/powernet.htm
on both LPC2106 and LPC2148 with external Ethernet controllers
from ASIX and RealTek. The performance was surprisingly good
providing that you code the GPIO interface *very* carefully.
The LPC2xxx parts with the fast GPIO (FIO) do better.

Stephen


-- 
Stephen Pelc, stephenXXX@mpeforth.com
MicroProcessor Engineering Ltd - More Real, Less Time
133 Hill Lane, Southampton SO15 5AF, England
tel: +44 (0)23 8063 1441, fax: +44 (0)23 8033 9691
web: http://www.mpeforth.com - free VFX Forth downloads

On Sun, 1 Jun 2008 08:47:58 -0700 (PDT), parekh.sh@gmail.com wrote:

>On Jun 1, 2:58 am, Mike Harrison <m...@whitewing.co.uk> wrote:
>> On Sat, 31 May 2008 20:23:16 -0700 (PDT), parekh...@gmail.com wrote:
>> >Hi All,
>>
>> >I am considering an application with Spartan-3 FPGAs.  I need to run
>> >TCP/IP and a few other networking applications along with other user
>> >logic.  The trade-off that I am considering is -
>>
>> >Microblaze inside the FPGA costs about 2000LCs.  I am considering I
>> >may be able to a lot more with those 2000LCs if I put an external ARM
>> >processor instead.  I am wondering if there exists a no-frills ARM
>> >chip out there that would cost me a buck or two, then I may be able to
>> >get more out of those 2000LCs.  Is there a chip out there?
>>
>> >TIA
>> >Sanjay
>>
>> NXP LPC210x series are very cheap - ought to be able to do TCP/IP etc.
>
>Thanks.  I see on their block diagram that the AHB does not get driven
>out.  Instead, the VPB what seems like a peripheral bus.  I wonder
>what kind of performance I can get from this bus.
>-sanjay

For highest speed, a FIQ driven parallel interface using FIO can give a pretty decent throughput
-From memory, when I interfaced a lo-res CMOS camera sensor, you can get something like 4Mbytes/sec
throughput. The only issue is whether you can get enough contiguous parallel I/O bits across the bus
without hitting a peripheral pin function you need to use. Losing pins to JTAG is also a potential
problem on the smaller parts, but you can always use a bigger part for development - LPC213x is a
good step-up from LPC2101/2/3 as the peripherals are pretty close to identical but JTAG is well
clear of them. 

>
> > NXP LPC210x series are very cheap - ought to be able to do TCP/IP etc.
>
> Thanks.  I see on their block diagram that the AHB does not get driven
> out.  Instead, the VPB what seems like a peripheral bus.  I wonder
> what kind of performance I can get from this bus.
> -sanjay

Hi Sanjay,

take a look at the LPC2220, this one has the AHB available, it also
offers 64k SRAM, which is probably enough to execute a TCP/IP stack at
full speed. It is also low cost, although not as low as the
LPC2101/2/3, which might not provide enough memory for a TCP/IP to
begin with.

Bob