How can I know the values for fine tune and coarse tune of crystal oscillator used in AD9364?
Do we need to conduct any experiment to fix those value?
Please refer https://wiki.analog.com/resources/eval/user-guides/ad-fmcomms2-ebz/hardware/tuning?s=dcxo
In that blog it is mentioned that once the error ppm is calculated, then specify the rectified clock frequency value in sysfs. What is this sysfs? Once I found out the offset in the Oscillator frequency, how can I estimate the fine and coarse tune value from that offset?
There are coarse tune and fine tune registers that can be modified using ad9361_set_dcxo_tune function. The resolution of the DCXO varies with coarse word with a worst-case resolution (at coarse word = 0) of 0.0125 ppm. Using both coarse and fine words, the DCXO can vary the frequency over a ±60 ppm range.
The tuning will be a continuous process where you will be increasing or decreasing the word as per the frequency error.
A factory calibration could also sweep the DCXO fine tune codes to produce a LUT of frequency error vs. fine tune code to allow quick updates of the XO tuning
How can I do factory calibration?
Can I have access to that LUT?
Please read below for details.
You need to create your own LUT as required.
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