How can I support legacy SFP modules with Agilex™ 5 FPGA and Agilex™ 3 FPGA GTS receivers?

Description

Altera® Agilex™ 5 FPGA and Agilex™ 3 FPGA device GTS receivers cannot tolerate 2V pk-pk signals from legacy SFP modules.

Resolution

You can support legacy SFP modules by adding inline 6dB RF attenuators in between the SFP module and the Agilex™ 5 FPGA and Agilex™ 3 FPGA device GTS receiver.

You must also power sequence the SFP module, ensuring that it powers up after the FPGA is configured.

The Agilex™ 5 FPGA and Agilex™ 3 FPGA device GTS equalizer in Auto Adaptation mode should open the RX eye for reduced amplitude SFP+ signals.

Altera recommend that you perform signal integrity analysis of your interface.