The Altera® 40G and 100G MACs will display the error message,"tx padding state machine is corrupt" if the connected Avalon® interface was not driven as expected. The following rules must be followed:
1. Packets must start with an SOP which will also be the MSB of the data, and end with an EOP. No additional SOPs or EOPs are allowed within a packet.
2. Their must be a minimum of two clock cycles between packets.
3. tx_valid must remain high during packet transmission.