from Si5351 import Si5351
  import fractions
  def asservissement(x):
  	freq=((x/1e7)*25);  # frequence de l'ordre de 720 MHz ajustable `a mieux que le Hz
  	a=int(freq/25)
  	u=(freq-a*25)/25;       # 700=28*25 i.e. a=28
  	t=fractions.Fraction(u).limit_denominator(1000000);
  	b=t.numerator
  	c=t.denominator
  
  	si = Si5351(busnum=1)
  
  
  	# vco = 25 MHz * (28 + 8 / 10) = 720 MHz
  	si.setupPLL(si.PLL_A, a, b, c)
  	#si.setupPLL(si.PLL_A, 24, 2, 3)
  	
  	# out0 = 720 MHz / 25 = 28.8 MHz 
  	si.setupMultisynth(0, si.PLL_A, int(25))
  	
  	# out2 = 720 MHz / 72 = 10 MHz 
  	si.setupMultisynth(1, si.PLL_A, int(72))
  	si.setupMultisynth(2, si.PLL_A, int(72))
  	
  	si.enableOutputs(True)