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