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