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