a pull up unit which pulls up {TAIL ~ an output terminal} of the data transfer unit in response to {HEAD ~ an output signal} from the first logic unit 
a pull up unit which pulls up { TAIL ~ an output terminal } of the data transfer unit in response to { HEAD ~ an output signal } from the first logic unit
OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH