Low Latency 40-Gbps Ethernet IP Core User Guide

ID 683745
Date 3/08/2021
Public
Document Table of Contents

3.2.1.7. Error Insertion Test and Debug Feature

The client can specify the insertion of a TX error in a specific packet. If the client specifies the insertion of a TX error, the LL 40GbE IP core inserts an error in the frame it transmits on the Ethernet link. The error appears as a 66-bit error block that consists of eight /E/ characters (EBLOCK_T) in the Ethernet frame.

To direct the IP core to insert a TX error in a packet, the client should assert the TX error insertion signal as follows, depending on the TX client interface:

  • On the Avalon-ST TX client interface, assert the l4_tx_error signal in the EOP cycle of the packet.
  • On the custom streaming TX client interface, assert bit N of the tx_error[1:0] signal in the same cycle in which bit N of din_eop[1:0] is asserted.

The IP core overwrites Ethernet frame data with an EBLOCK_T error block when it transmits the Ethernet frame that corresponds to the packet EOP.

This feature supports test and debug of your IP core. In loopback mode, when the IP core receives a deliberately errored packet on the Ethernet link, the IP core recognizes it as a malformed packet.