Altddio - rgmii

Altera_Forum · ‎10-31-2014

Hi,

I'm preparing design on Cyclone V with RGMII connection. I read AN 477 ("Designing RGMII Interfaces with FPGAs and HardCopy ASICs") about it and I understand what is necessary to do. I miss only one major information. It is necessary to use DQ/DQS pins on FPGA for TXD and RXD pins?

Thanks,

Milan

Altera_Forum · ‎10-31-2014

I believe it should work with regular DDR I/O. (Cyclone V and 28nm is getting slow enough with source-synch I/O that it's not a slam dunk, but I believe I've seen it done.)

Altera_Forum · ‎10-31-2014

OK, I can connect RX and TX data on DQ pins but how about RX_CLK and TX_CLK? Has they be connected on dedicated CLK pin or on the DQS pin? I can imagine, that the receive clock is on DQS pin and transmit clock is on dedicated CLK pin, but I'm not sure that it is right solution.