Tx signals for raw ethernet frame

[dylanpjx]

Hi Alex, I'm trying to modify ip_eth_tx_64 to transmit raw ethernet frames. Since there's no IP header fields involved, how should the hdr_valid/ready signals to and fro eth_axis_tx be handled? Issue #55 seem to suggest that hdr_valid signal is an indication of the start of a new frame and is always required. Would that mean that I should simply send the first two 64-bit packets of my payload as a "header"?

I'm observing something like this for ip_eth_tx_64 on SignalTap (without any modifications) but it does not exactly match the signals shown on the readme:

[dylanpjx]

I have gotten it working for anyone else that wants to do something similar.

For the first 64 bits of the payload, set hdr_valid to high. Deassert hdr_valid once hdr_ready is high for one clock cycle. m_axis_tvalid should be high throughout the entire payload (including the first 64 bits of payload). An easy way to test would be to include eth_axis_tx in simulation and let the FIFO supply the tready signals.