AN 766: Intel® Stratix® 10 Devices, High Speed Signal Interface Layout Design Guideline

ID 683132
Date 3/12/2019
Document Table of Contents

Connector Signal and Pin Assignment

Intel recommends the TE Connectivity® 3.9 mm STRADA Whisper connector (R/A receptacle) or IMPACT connector for the 25+ Interlaken interface. This connector is ideal for cabled connections. The part number is TYCO 2187194-1. This connector can handle both TX and RX signals. The cable assembly crosses the signal to provide connectivity from TX to RX and from RX to TX. A single connector supports up to 24 channels (24 TX and 24 RX). The advantage of this connector is that it can operate up to 57.8 Gbps with no skew in pair.

Figure 98. Interlaken Single or Dual Connector Setups

The single connector allows up to 22 lanes of high-speed differential connectivity to another board for interoperability. The Interlaken Alliance currently specifies only 20 lanes are needed for interoperability.

The dual connector setup allows up to 44 lanes of high-speed differential connectivity to another board. In this case, the Interlaken Alliance currently specifies the need for only 40 lanes for interoperability. The connector and cable assembly are rated to support data rates up to 28.9 Gbps with non-return to zero (NRZ) encoding.

Note: TX[20:21] and RX[20:21] are spare lanes that you can use for other cases where extra lanes may be required.
Figure 99. Connector Signal Pin Assignment and Magnified View of Signal PinsPin assignments for the high-speed differential pairs. Signals labeled TX are outputs from the board, while RX signals are inputs to the board.

The cable assembly connecting each PCB's on-board connector(s) (STRADA Whisper connectors to R/A receptacles) takes care of swapping TX to RX. Therefore, the connector pinouts are identical on either inter operating board.

Note: TX_REFCK_P/N and RX_REFCK_PN are not provided for high-speed physical interoperability.

The insertion loss of the connector is less than 1 dB and is linear up to 20 GHz. For an 85 Ω channel, Intel recommends that you use the 85 Ω version of the connector. Likewise, for a 100 Ω channel, Intel recommends that you use the 100 Ω version of the connector. There is little to no skew through the high-speed differential pairs within the connector.