40GbE IP Core Locks Up or Sends Incorrect Packets if SOP or EOP is Asserted While Valid is Not Asserted on the Avalon-ST TX Client Interface

Description

If user logic asserts the l4_tx_startofpacket or l4_tx_endofpacket signal on the Avalon-ST client interface of a 40GbE IP core while not asserting l4_tx_valid, the IP core could:

• Lock up, or
• Send incorrect packets to the Ethernet link.

Resolution

To avoid this issue, ensure you gate the l4_tx_startofpacket and l4_tx_endofpacket signals with the l4_tx_valid signal in your 40GbE design.

This issue is fixed in version 15.0 Update 1 of the 40-100GbE IP core.