Preamble Mode Register in 10-Gbps Ethernet MAC Cannot Be Read - Preamble Mode Register in 10-Gbps Ethernet MAC Cannot Be Read Description You can only write to the RX Preamble Control (0x100:0x13F) register in the 10GbE MAC MegaCore function, but you cannot read the value of the register. The value cannot be read because the csr_readdata port is in dangling state and it is not connected to RX Preamble Control register. This issue affects all designs that use the RX Preamble Control register in version 13.0 of the 10GbE MAC MegaCore function. Resolution There is no workaround for this issue. This issue will be fixed in a future version of the 10GbE MAC MegaCore function. Custom Fields values: ['novalue'] Troubleshooting novalue True ['Ethernet'] ['FPGA Dev Tools Quartus II Software'] novalue 13.0 ['Programmable Logic Devices'] ['novalue'] ['novalue'] ['novalue']