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AD-FMCOMMS4-EBZ RX LO Tuning Issue

Question asked by thisguy on Mar 9, 2015
Latest reply on Mar 9, 2015 by rgetz

I am currently working with the AD-FMCOMMS4-EBZ and I am having an issue tuning the RX LO frequency to within an acceptable accuracy. Before I go any further let me give you a quick overview of my setup.

 

I am running a AD-FMCOMMS4-EBZ with a ZedBoard (Zynq SDR-II Eval.).

I have setup all the Xilinx tools to use the No-OS API for the AD-FMCOMMS2-EBZ which is the AD9361 chip. I know that the FMCOMMS4 has the AD9364 chip, but the wiki pages for this card redirect you to the AD9361 SW and HDL pages. A quick glance looks like all the registers are the same for either chip and on boot of the No-OS API software I get a successful initialization message.

 

The issue I am having is that when the board comes up and the RX LO is tuned, I have seen the LO off by ~2kHz at 750MHz and ~4kHz at 2400MHz (the AD-FMCOMMS4-EBZ initial state at boot up). I cannot find the exact reference in the user guide (UG-672), but I remember reading that the ad9361_set_rx_lo_freq function should handle LO calibration for jumps exceeding 100MHz, however this does not seem to be the case even on start up.

 

Could it be that I have the wrong API for this board and if so where is the correct SW package?

What registers should I look at to confirm a calibration is being done?

 

I would greatly appreciate any help with this issue.

 

Thanks

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