A 1000BASE-X PHY can be implemented directly in the FPGA using the 1G/2.5G Ethernet PCS/PMA or SGMII module configured in 1000BASE-X mode. This can be connected directly to an external optical module.The AXI 1G/2.5G Ethernet subsystem can be configured in non-processor mode where the buffer module is not present. In this mode, all of the ports and interfaces are directly connected to the TEMAC and the PCS PMA. Non-processor mode can be enabled only for SGMII or 1000BASE-X.