After deassertion of the system reset, the
built-in self-calibration (BISC) of the PHY is run. BISC is used in the PHY to compute
internal skews for use in voltage and temperature tracking after calibration is
completed. In this calibration stage, internal delays are measured to determine the
number of fine taps required to equal a quarter clock memory period. This is referred to
as a coarse tap.