F-tile Architecture and PMA and FEC Direct PHY IP User Guide

ID 683872
Date 12/15/2021
Public

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2.1.6. Bonding Architecture

Streams or PMAs are bonded together under the following conditions:

  • When a transmitter (TX) or receiver (RX) PMA lane operates at a data rate above 32 Gbps in the high data rate PAM4 mode (PMA bonding)
  • When there are multiple TX PMA lanes in PAM4 or NRZ mode (system bonding)

For PMA bonding when a TX or RX PMA lane operates at a data rate above 32 Gbps, use:

  • Two streams for up to 58 Gbps (in FGT and FHT PMAs)
  • Four streams for up to 116 Gbps (in FHT PMAs only)

System bonding for multiple TX PMA lanes is a technique used to minimize high-speed, serial, lane-to-lane transmit skew for multi-lane protocols (see the Intel® Agilex® Device Data Sheet for the skew specification). This technique bonds multiple streams from multiple TX PMA lanes together. For example:

  • In 200G hard IP Ethernet with four FGT PMA lanes where each PMA lane has two streams, eight streams are bonded together.
  • In 400G hard IP Ethernet with four FHT PMA lanes where each PMA lane has four streams, 16 streams are bonded together.

Any reference clock on the same tile can be used for the bonded lanes provided that its clock network spans all bonded lanes. Refer to Clock Networks for information about the reference clock network span.

When bonded streams use a system PLL, they must all use the same system PLL. For example, six-stream, JESD204B, TX-only IP uses the same system PLL for all six TX streams.

Whenever bonding, all things in the bond must be on the same clock.

You can only bond lanes within the same tile, either within the 16 FGT PMA lanes or within the four FHT PMA lanes. TX PMA bonded lanes must be placed contiguously with the primary PMA lane at a pre-defined location based on the fracture type. See the F-Tile Channel Placement Tool and Bonding Placement Rules for details.

Unsupported bonding conditions:

  • Bonding between FGT and FHT PMA lanes
  • Bonding between 400G hard IP and 200G hard IP

There are three mechanisms to facilitate bonding:

  • Sharing a TX and RX PMA recovered clock network at the PMA interface
  • Synchronizing a reset or read and write at the PMA interface
  • Removing skew with EMIB interface deskew logic

400G hard IP, 200G hard IP, and PCIe* hard IP all have TX and RX deskew logic. The deskew logic removes the skew of multiple bonded streams across the EMIB.

Table 10.  Number of Bonded Streams Supported by Deskew Logic in 400G Hard IP and 200G Hard IP
Hard IP Number of Supported Bonded Streams in 400G Hard IP Number of Supported Bonded Streams in 200G Hard IP
F-tile PMA and FEC Direct PHY IP 2, 4, 6, 8, 12, 16 2, 4, 6, 8
F-tile Ethernet hard IP 2, 4, 8, 16 2, 4, 8

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