Hi all,

[email protected]

I'm trying to introduce a way to align the IP header so it starts on a 32 bit 
word. This when using the DMA function so that the stored word is aligned in 
RAM.

Today we have this :

----------------- <- Byte 0
| MAC header    |
| 14 bytes      |
----------------- <- Byte 14 (NOT word aligned: problematic)
| IP header     |
-----------------
| Data          |
-----------------
| Unused        |
----------------- <- Byte 1536 (I think...)

I'm using the ethmac fr OC (Igor Mohors). Latest version.

So I' have added a bit to align in eth_registers.v meaning the following: 

----------------- <- Byte 0
| 2 empty bytes |
-----------------
| MAC header    |
| 14 bytes      |
----------------- <- Byte 16 (word aligned, this is the what we want)
| IP header     |
-----------------
| Data          |
-----------------
| Unused        |
----------------- <- Byte 1538 (I think...)

In the eth_wishbone.v 

RxStartFrm indicates start of frame. RxbyteSel indicates active bytes in the 
word. 

My question is if I can insert 2 dummy bytes to align the by manipulating the 
insert of data with the RXPointerLSB_rst and RxBytecnt to add these tvo extra 
"dummy" bytes.

Regards 
Stefan
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