This American National Standard describes the physical interface portions of a high performance serial link based on the work of the XFP MSA. FC-PI-3 applies only to the variant described in FC-PI-3 and does not affect or supersede any requirements in any other FC standard or technical report.

This specification defines the electrical interfaces called XFI+ based on INF-8077(XFI) the XFP MSA for high-speed serial operation from 9.95-11.1 Gigabaud. This specification enhances the XFI specification to achieve greater printed circuit board (PCB) trace length and changes the return loss for the ASIC/SerDes to improve manufacturability. The acronym XFI+ is used herein to describe this interface. The XFI+ interface is defined to operate over 200-300 mm of PCB traces that connect to an optical module or another device with XFI+ interface. XFI+ is defined for 10GFC operating at 10.52 Gigabaud, however the same specification can support Datacom applications (e.g.,10 Gb/s Ethernet) and Telecom e.g., (SONET OC-192 and G.709 "OTU-2"). Nominal symbol rates include 9.95GBd, 10.31GBd, 10.52GBd, 10.70GBd, 11.09GBd (Ethernet plus FEC) and 11.31GBd (10GFC plus FEC). The modules support all data encoding for these technologies. The modules may be used to implement single mode or multi-mode serial optical interfaces at 850 nm, 1310 nm, or 1550 nm.

The FC-PI-3 specification includes the following information:

a) XFP reference model and description

b) High-Speed Electrical Specification XFI+

c) Implementation and measurement suggestions.

1) Compliance Test Points and Boards (Normative)

2) XFI+ Channel Measurements and Modeling (Informative)

3) Differential S-Parameters and TDR (Informative)

4) Optimum Via Design

5) Jitter Methodology and Measurement (Normative)

FC-PI-3 is for a single electrical variant based on 64B/66B coding in datacom applications, which is complementary to the serial optical variants described in 10 GFC.