Re: [Discuss-gnuradio] Programming PLL on RFX900/1800

[Marcus D. Leech]

Hi, I have an RFX900 board and sometimes when I run usrp_fft.py and try to set frequency I get a message at the bottom of the window saying "Failed" or "Failed to set initial frequency".

The PLL chip is programmed via a shift register (SPI) and as far as I know reading from the chip is not possible. One can only write to the PLL chip (ADF4360).

So my question is : where does the "Failed" message come from? What and where is being checked to verify success or fail ?

 

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Two points:

You should perhaps look at the source code of the USRP drivers for the RFX900 board.

The "classic" drivers (pre-UHD) have been obsolete for several years now, so unless you have a strong reason to stick with the "classic"
  drivers for USRP1, you should upgrade your life to UHD.

I haven't looked at the code for that, but it's likely that it's looking at the MUXOUT pin via one of the FPGA GPIO lines -- MUXOUT on that synthesizer
  can be programmed to provide lock-detect.

-- 
Marcus Leech
Principal Investigator
Shirleys Bay Radio Astronomy Consortium
http://www.sbrac.org