Hello,
I am working with a custom FPGA image on an Ettus X440. My current goal is to transmit a custom waveform directly from the FPGA via the RFDC tile, without using UHD.
I have verified that a DDS tone is present at the RFDC streaming input. However, I am not seeing RF energy at the TX/RX0 port.
I suspect a daughterboard / carrier configuration is missing. The analog path on the X440 is controlled via an I2C expander, and I would like to be able to read and write those registers from my FPGA design to verify the TX enable, antenna select, and attenuator settings. Is there a recommended way to access those I2C registers from bare-metal / PL logic?
Separately, we are running custom RX logic in the PL. When UHD is used, the RX path appears to be disconnected. I suspect this may also be a carrier configuration issue. I have been trying to trace the relevant control signals through X440_FPGA.htm but am having difficulty following the axi mapping.
Any insight on the carrier enable sequencing or how to locate the TX/RX configuration would be extremely helpful.
Thanks,
Troy
