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Altera_Forum
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14 years ago

payload pad removal in Altera TSE

Hi all!

I would like to know how payload pad removal works in the aLtera TSE IP.

How does the TSE know the payload length if ethernet header field "length/type" carries a type info (e.g. 0x0800 = IPv4 type)?

Thx

6 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    The addition/removal is for 32bit alignment, so the core itself doesn't care what length or type the packet is.

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    Altera_Forum
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    I'm sorry but I don't understand what you mean.

    Can you develop please?

    Thx

    Julien
  • Altera_Forum's avatar
    Altera_Forum
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    Hello J_Renauld,

    I know it's almost a year ago,

    but did you or somebody else find out how pad removal works?

    Because in my case it doesn't work (alltough I set the PAD_EN bit) and in assumption with the Leightweight IP-Stack and TCP I think it is not nice, that after every Connection establishment the Client sends back another ACK, because he thinks that there was some data in the ACK of the Client becaus of padding.

    Best Regards,

    Elegan
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    Altera_Forum
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    Hm, I see no problems with LwIP and TSE. 32bit alignment flag is set in TSE options as it is also set in LwIP driver options.

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    Altera_Forum
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    Sorry Socrates, but I think here you mean something different.

    I think you mean the two byte which TSE puts in front of the Ethernet-Header to achive a 32-bit alignment.

    In this case are the missing bytes meant, which are put at the end of the frame to achieve the minimum ethernet frame length of 64 byte.