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fpgause
Observer
Observer
6,227 Views
Registered: ‎11-13-2010

lwip without external ram possible?

If i increase the bram memory by adding more block rams then i will  be able to save whole lwip libraries in block ram but i want to confirm will the lwip libraries  work without external memory(means without saving in external memory ).Need to confirm it so that i can proceed further....

Thanks

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6 Replies
joshual
Xilinx Employee
Xilinx Employee
6,170 Views
Registered: ‎08-01-2007

it depends on the application and mode you are using with lwip, and also what the bram size you are using?

You can try with xapp1026 and add you app to see if it is ok to optimize
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aminfar1
Explorer
Explorer
6,109 Views
Registered: ‎01-09-2009

You might be able to do so by having multiple LMB BRAM controllers on the same LMB bus. Note that the largest supported size for a 32-bit on-chip BRAM controller on either Virtex-5 or Virtex-6 is 256KB. I am not sure if SDK is abe to partiotion code between multiple controllers. I think LWIP size is about 1MB (not sure).

 

I haven't done that, but I'm interested in knowing if other people have tried that.

 

EDIT: Seems like a Xilinx employee has said that you have to have external memory:

http://forums.xilinx.com/t5/Embedded-Processing/LwIP-without-external-RAM-possible/td-p/108455

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kdc71726
Visitor
Visitor
5,924 Views
Registered: ‎06-23-2011

Has anyone confirmed if LwIP will fit in the BRAM? I have tried lowering different parameters like the buffer sizes as well as increasing the BRAM, but still have not been able to get it to fit.
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aminfar1
Explorer
Explorer
5,916 Views
Registered: ‎01-09-2009

Nop, this is not possible. At least I haven't heard of anyone doing this. See my post above.

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kdc71726
Visitor
Visitor
5,910 Views
Registered: ‎06-23-2011

Thanks. And do you happen to know if it's possible to get anywhere near 1 Gbps with UDP using external RAM?
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aminfar1
Explorer
Explorer
5,907 Views
Registered: ‎01-09-2009

No idea. Sorry.

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