In absence of a clock signal received at the first node, the second circuit uses the frequency reference input received at the second input node to control {HEAD ~ the frequency} of {TAIL ~ the oscillator} 
of
In absence of a clock signal received at the first node , the second circuit uses the frequency reference input received at the second input node to control { HEAD ~ the frequency } of { TAIL ~ the oscillator }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL