Transceiver Logic For Ultrascale+/UltraScale Devices - 16.2 English

1G/2.5G Ethernet PCS/PMA or SGMII LogiCORE IP Product Guide (PG047)

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16.2 English

The following figure shows the connectivity of clocking logic with encrypted core and transceiver channel. The internal signal names of the GT_CHANNEL or the encrypted RTL might not exactly correspond to the block level port names. For connectivity purposes at the block level see Port Descriptions. For shared logic connectivity guidelines see Clock Sharing Across Multiple Cores with Transceivers.

The clock buffer on RXOUTCLK in the diagrams is a part of the clocking logic shown below for simplification.

The differential reference clock selected through Vivado IDE is routed directly to the UltraScale+/UltraScale FPGA transceiver. The transceiver is configured to output a version of this clock (125 MHz for 1 G, 312.5 MHz for 2.5G) on the txoutclk port; txoutclk is then routed to a BUFG_GT to generate userclk (62.5, 125MHz for 1G and 312.5, 156.25 MHz for 2.5G), userclk2 (125 MHz for 1G, 312.5 MHz for 2.5G) and placed onto global clock routing. These clocks are input back into the transceiver on the user interface clock ports usrclk and usrclk2. The clocking logic is included in a separate module <component_name>_clocking which is instantiated in the <component_name>_support module.

Transceiver files are generated on runtime through UltraScale+/UltraScale gtwizard. See the UltraScale Architecture GTH Transceivers User Guide (UG576), the UltraScale Architecture GTY Transceivers User Guide (UG578), and the FPGAs Transceivers Wizard LogiCORE IP Product Guide (PG182) for details on the supporting logic and files generated.

Figure 1. 1G SGMII Transceiver Connections (UltraScale Architecture)