Hi there. I am using the ZCU102 + ADRV9026 reference HDL design, and every time I power up the board, I can see a tone at the same frequency on all 4 TX channels. I've been able to disable these tones via the Linux kernel driver by simply powering down the TX channel enable signals, as well as ensuring the I Q path buffers are disabled. However, if I send an IQ stream out of a TX channel (and re-enable the channel/IQ stream), once my stream is finished transmitting and my control script exits, I see the DDS tones reappear. I have even un-wired the JESD interface in the reference design to rule out an IQ-generated tone on one of the channels, so I am presuming the tone is generated with the DDS.
DDS tones after initial board power-up:
After channel disable (have tried this with setting '0' to 'out_voltageX_en', and also with pyadi-iio 'dds_disable()' command):
Any time the channel is re-enabled for sending an IQ file through, the same DDS tone reappears. Is there a way I can send my own IQ data through the ADRV without any DDS/other signals out of the TX channels? Is there a default control register in the reference HDL design that initiates the DDS tone? Any help is appreciated.
