The double speed clock signal has a frequency twice as large as {HEAD ~ the frequency} of {TAIL ~ the internal memory controller clock signal} 
The double speed clock signal has a frequency twice as large as { HEAD ~ the frequency } of { TAIL ~ the internal memory controller clock signal }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL