Calibration is performed at device configuration, but during normal operation the voltage and temperature can change. Voltage and temperature (VT) drift can have an effect on the alignment of the DQS with the DQ bits. VT tracking is a feature where the internal clocks that have been matched with the memory clock strobes (DQS) are monitored and adjusted to track any variations from the original calibrated values.
|The number of fine taps in a quarter clock period
|The largest number of fine taps in a quarter clock period since the tracking has started
|The smallest number of fine taps in a quarter clock period since the tracking has started