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Altera_Forum
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16 years ago

Altera TSE driver and example program for lwIP (1.3.2)

After many many requests and complaints about lack of support and/or documentation for support of lwIP for the Altera TSE, I have developed a drop-in TSE driver and example program and made this avai...
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Altera_Forum
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14 years ago

There may be a much faster way to handle these 1-3 byte SGDMA transfers.

I believe it to be true that there would only be one 1-byte pbuf in a chain, is this true? If it *is* true, you could ensure that all pbufs are allocated with an extra 4 bytes of payload. This would be done for PBUF_POOL (not sure about PBUF_RAM). Take the 1 to 3 bytes of the next pbuf and add it to the end of the payload of the preceding one. Increase that len by 1 to 3 and set the second one to 0. Leave the chain in place but skip pbufs with len==0.

This would be very efficient for the common case of a trailing short pbuf chain.

For PBUF_REF you may have to unwind to a new pbuf. Or ensure 0-copy doesn't use small payloads (probably not hard to manage).

Bill