Why does the 1G/2.5G/5G/10G Multi-rate Ethernet PHY IP Core fail to establish the link in 1G or 2.5G speed mode? - Why does the 1G/2.5G/5G/10G Multi-rate Ethernet PHY IP Core fail to establish the link in 1G or 2.5G speed mode? Description Due to a problem in the 1G/2.5G/5G/10G Multi-rate Ethernet PHY IP Core version 15.1 and 16.0, the PHY RX may get stuck in a failure state and fail to establish the link when contiguous special code-groups (/K28.1/, /K28.5/, and /K28.7/) are received. The PHY RX outputs gmii16b_rx_d[15:0]=0x0E0E , gmii16b_rx_dv[1:0]=0x0 , and gmii16b_rx_err[1:0]=0x3 if the PHY IP is stuck in the failure condition. Resolution To work around the problem, reset the PHY IP Core through the control register bit[15] RESET or restart auto-negotiation through the control register bit[9] RESTART_AUTO_NEGOTIATION . This problem is scheduled to be fixed in a future release of the Quartus® Prime Software. Custom Fields values: ['novalue'] Troubleshooting novalue False ['novalue'] ['FPGA Dev Tools Quartus® Prime Software Pro'] novalue 15.1 ['Programmable Logic Devices'] ['novalue'] ['novalue'] ['novalue']