in a third cycle, {HEAD ~ old data} are written back into {TAIL ~ the DRAM memory}, and new data from the DRAM memory are transferred into the cache memory to replace old data 
are written back into
in a third cycle , { HEAD ~ old data } are written back into { TAIL ~ the DRAM memory } , and new data from the DRAM memory are transferred into the cache memory to replace old data
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH