the second input node is adapted to be connected to a filter when {HEAD ~ the externally provided clock signal} is provided at {TAIL ~ the first input node}, 
is provided at
the second input node is adapted to be connected to a filter when { HEAD ~ the externally provided clock signal } is provided at { TAIL ~ the first input node } ,
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH