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

ID 683872
Date 4/01/2024
Public
Document Table of Contents

3.9. Bonding Implementation

Bonding enables you to minimize skew between channels. You can accomplish bonding between channels by the sharing of TX and RX PMA clocks and synchronizing resets, read enables, and write enables at the PMA interface. The bonding implementation supports up to 16 channels of the FGT PMA, and up to 4 channels of the FHT PMA. In F-tile, there are two components to bonding: PMA bonding and System bonding.

PMA Bonding

PMA bonding is the bonding of streams to and from the PMA channels. For example, on an Ethernet 112G PMA that requires four streams to form a channel, both the TX and RX directions have PMA bonding.

Note: For information on the maximum channel-to-channel skew to expect with TX PMA bonding, refer to the Agilex™ 7 Device Data Sheet.
Note: Use the F-Tile Channel Placement Tool for your PMA channel placement.

System Bonding

System bonding is the bonding of lanes into a single link. For example, in 400GbE Ethernet, which uses 112G PMAs, each PMA takes four streams. The four streams per PMA are bonded. In turn, these four PMA/stream groupings are all bonded together. Consequently, this 400GbE interface example requires 16 streams. These streams are all bonded together through system bonding.

Note: System bonding in the RX direction is achievable only when using a System PLL as the clock source.

Enabling Bonding in the Parameter Editor

In F-tile, you enable bonding with the Number of PMA Lanes and PMA width parameters in the Common Datapath Options group box in the parameter editor.

Figure 89. Enabling Bonding in the Parameter Editor

The Quartus® Prime software implements bonding automatically, according to your specifications for Number of PMA Lanes and PMA width parameters. The following table illustrates the parameter settings needed to achieve PMA or system bonding:

Table 86.  Parameter Settings to Implement PMA and System Bonding
Bonding Implementation Number of PMA Lanes PMA Width
No Bonding = 1 =< 32-bit
PMA Bonding = 1 64, 128
System Bonding > 1 =< 32-bit
System and PMA Bonding > 1 64, 128

When system bonding is enabled and the Datapath clocking mode is set to PMA, select Bond Clock for the Selected tx_clkout clock source parameter in the TX Clock Options group box.

Figure 90. TX Clock Options

Similarly, when bonding is enabled and the Datapath clocking mode is set to PMA, select Bond Clock for the Selected rx_clkout clock source parameter in the RX Clock Options group box.

Figure 91. RX Clock Options

By selecting Bond Clock for the Selected tx_clkout clock source and Selected rx_clkout clock source parameters, you ensure that the primary stream of the bonded group drives the tx_clkout and rx_clkout sources.

When bonding is enabled and the Datapath clocking mode is set to System PLL, select either Sys PLL Clock or Sys PLL Clock Div2 for the Selected tx_clkout clock source and Selected rx_clkout clock source parameters, respectively.

Note: Bonding is not supported across tiles, between FGT and FHT lanes, or between the 200G and 400G hard IPs.