Low Latency Ethernet 10G MAC Intel® FPGA IP User Guide: Agilex™ 5 FPGAs and SoCs

ID 813663
Date 7/08/2024
Public
Document Table of Contents

3.8. XGMII Error Handling (Link Fault)

The Low Latency Ethernet 10G MAC supports link fault generation and detection.

When the MAC RX receives a local fault, the MAC TX starts sending remote fault status (0x0200009c) on the XGMII. If the packet transmission was in progress at the time, the remote fault bytes override the packet bytes until the fault condition ceases.

When the MAC RX receives a remote fault, the MAC TX starts sending IDLE bytes (0x07070707) on its XGMII. If packet transmission was in progress at the time, the IDLE bytes override the packet bytes until the fault condition ceases.

The MAC considers the link fault condition has ceased if the client and the remote partner both receive valid data in more than 127 columns.

Figure 25. Fault Signaling
Figure 26. XGMII TX interface Transmitting Remote Fault SignalFigure shows the timing for the XGMII TX interface transmitting the remote fault signal.

When you instantiate the MAC RX only variation, connect the link_fault_status_xgmii_rx_data signal to the corresponding RX client logic to handle the link fault. Similarly, when you instantiate the MAC TX only variation, connect the link_fault_status_xgmii_tx_data signal to the corresponding TX client logic.