Number of oscillators should be 8 if MF enabled

[qSaevar]

Changes proposed in this pull request:

• If MF is enabled in ZI UHFLI there are 8 oscillators that can be controlled.
• Sampling rate as float should return exact value, not rounded off value.

@WilliamHPNielsen

[codecov]

Codecov Report

Merging #1546 into master will decrease coverage by <.01%.
The diff coverage is n/a.

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[codecov]

Codecov Report

Merging #1546 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #1546   +/-   ##
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  Coverage   71.22%   71.22%           
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  Files         103      103           
  Lines       12002    12002           
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  Hits         8549     8549           
  Misses       3453     3453

[WilliamHPNielsen]

Let me see if I get this...

I'll just trust you on the number of oscillators. Regarding the frequency, the point is that the graphical interface specifies the available sampling rates as

['1.80 GHz', '900 MHz', '450 MHz', '225 MHz', '113 MHz', '56.2 MHz',
'28.1 MHz', '14.0 MHz', '7.03 MHz', '3.50 MHz', '1.75 MHz', '880 kHz', '440 kHz', '220
kHz', '110 kHz', '54.9 kHz', '27.5 kHz']

but you and I both know that these numbers are not exact, merely rounded off to 3 significant digits. In fact, the true frequencies are 1.80 GHz divided by 2**n, which means that (in Hz), they are

[1800000000.0,
 900000000.0,
 450000000.0,
 225000000.0,
 112500000.0,
 56250000.0,
 28125000.0,
 14062500.0,
 7031250.0,
 3515625.0,
 1757812.5,
 878906.25,
 439453.125,
 219726.5625,
 109863.28125,
 54931.640625,
 27465.8203125]

, i.e. all numbers that can be represented exactly.

Okay, I get it. I agree.

[WilliamHPNielsen]

The only weakness is: how well do we know the original frequency?

@qSaevar ?

[qSaevar]

@WilliamHPNielsen the original frequency? Do you mean the base 1.8GHz or the internal ref frequency? In the manual it is stated that the short term stability of the internal clock is 0.00005 ppm with typical initial accuracy of +/- 0.5 ppm and max of +/- 1 ppm. But then there is the possibility of using an external reference clock...

[qSaevar]

@WilliamHPNielsen I fixed the setter for sampling rate and I have tested this on hardware. Should I do anything else? Or what is the status of this PR.

[WilliamHPNielsen]

@qSaevar I meant the base frequency of 1.8 GHz. If that could potentially be 1.804 GHz, things would be bad. But you've answered that question now, thanks.

We'll merge once CI is happy.

[qSaevar]

@WilliamHPNielsen That's great, thanks