GTS Ethernet Intel® FPGA Hard IP User Guide

ID 817676
Date 10/12/2024
Public
Document Table of Contents

A.2.4. Link Fault Signaling

If you enable Link Fault Generation Mode in the GTS Ethernet Intel® FPGA Hard IP parameter editor, the IP core provides link fault signaling as defined in the IEEE 802.3-2018 IEEE Standard for Ethernet.

The Ethernet MAC includes a Reconciliation Sublayer (RS) located between the MAC and the MII to manage local and remote faults. Link fault signaling on the Ethernet link is disabled by default but can be enabled by bit [0] of the link_fault_config register. When the link_fault_config register bits [1:0] have the value of 2'b01, link fault signaling is enabled in normal bidirectional mode. In this mode, the local RS TX logic transmits remote fault sequences in case of a local fault and transmits IDLE control words in case of a remote fault.

If you turn on bit [1] of the link_fault_config register, the IP core conforms to Clause 66 of the IEEE 802.3-2018 IEEE Standard for Ethernet. When link_fault_config[1:0] has the value of 2'b11, the IP core transmits the fault sequence ordered sets in the interpacket gaps according to the clause requirements.

The RS RX logic sets o_remote_fault_status or o_local_fault_status to 1 when the RS RX block receives remote fault or local fault sequence ordered sets. When valid data is received in more than 255 columns, the RS RX logic resets the relevant fault status (o_remote_fault_status or o_local_fault_status) to 0.