The AXI4-Stream interface is statically configurable into one of two major modes of operation. The desired mode is selected using the control fields ctl_tx_independent_tsmac_and_phy_mode and ctl_rx_independent_tsmac_and_phy_mode of the GLOBAL_MODE register.
In all modes, the AXI4-Stream interface uses the tx_axi_clk for the TX path and the rx_axi_clk for the RX path.