The data blocks are error checked by an error check unit and the number of {HEAD ~ erroneous data blocks} is stored in {TAIL ~ memory} 
The data blocks are error checked by an error check unit and the number of { HEAD ~ erroneous data blocks } is stored in { TAIL ~ memory }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH TAIL TAIL TAIL TAIL TAIL