F-Tile Triple-Speed Ethernet Intel® FPGA IP User Guide

ID 741328
Date 4/15/2024
Document Table of Contents SGMII Auto-Negotiation

In SGMII mode, the capabilities of the PHY device are advertised and exchanged with a link partner PHY device.

Possible application of SGMII auto-negotiation in MAC mode and PHY mode.

Figure 33. SGMII Auto-Negotiation in MAC Mode and PHY Mode

If the SGMII_ENA and USE_SGMII_AN bits in the if_mode register are 1, the PCS function is automatically configured with the capabilities advertised by the PHY device once the auto-negotiation completes.

If the SGMII_ENA bit is 1 and the USE_SGMII_AN bit is 0, the PCS function can be configured with the SGMII_SPEED and SGMII_DUPLEX bits in the if_mode register.

If the SGMII_ENA bit is 1 and the SGMII_AN_MODE bit is 1 (SGMII PHY Mode auto-negotiation is enabled) the speed and duplex mode resolution will be resolved based on the value that you set in the dev_ability register once auto negotiation is done. You should use set to the PHY mode if you want to advertise the link speed and duplex mode to the link partner.

Figure 34. SGMII Auto-Negotiation Activity

For more information, refer to CISCO Serial-GMII Specifications.