Connecting Intel Agilex FPGA to DE1-SoC via Hub

Hello Pedro,

The Intel Agilex FPGA supports multi-rate Ethernet, including 1 GbE. However, successful communication with the DE1-SoC (which is limited to 1 GbE) depends not only on the FPGA IP configuration, but also on the external PHY and optical module used.

In general, QSFP-DD interfaces are designed for higher data rates (10G and above) and may not support 1 GbE operation or automatic downspeeding. As a result, a direct connection through a 1 GbE hub may not work if the QSFP-DD module does not support 1 GbE.

Recommended approach:

Configure the Agilex Ethernet IP to operate at 1 GbE (1000BASE-X or SGMII) if supported.

Use a QSFP-DD to SFP adapter with a 1 GbE SFP module (copper or fiber) to ensure compatibility with the 1 GbE hub and DE1-SoC.

Alternative:

If 1 GbE operation is not supported on the QSFP-DD interface, use a media converter to bridge between 10 GbE and 1 GbE.

This approach ensures proper link establishment and reliable communication between the devices.