The pin test buffer inputs external inputs to {HEAD ~ a pin}, and outputs to {TAIL ~ the same pin} from the device 
The pin test buffer inputs external inputs to { HEAD ~ a pin } , and outputs to { TAIL ~ the same pin } from the device
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH