Clock Oscillators

Note: The clock oscillators are separate and not synchronous to the clock provided by the USB host interface.

In addition to the USB host interface clock, three fixed-frequency clock oscillators provide reference clocks for various FPGA components and systems.

  • Fabric / DDR4 Clock – This is a general-purpose 100 MHz clock for logic use. This clock should be used as the reference for designs using the DDR4 memory.
  • MGT Clock – This is an on-board reference for the gigabit transceiver quad on bank 225 refclk 0. Additional clocks may be provided externally for banks 224, 225, and 226 through the MC3 expansion connector.

Pin Mappings

Fabric / DDR4100 MHzJ23 / J24 (Bank 66)
MGT125 MHzV7 / V6 (Bank 225)