A method of phase calibration for a system to control a double data rate memory device includes setting a scanning frequency at an initial value to determining if a built-in self-test passes, decreasing the scanning frequency by a frequency decrement and then performing the BIST again until the BIST passes, performing a phase calibration procedure to obtain a phase window with respect to the scanning frequency and obtain a target phase obtained based on the phase window to determine if the scanning frequency is lower than a maximum value, and increasing the scanning frequency by a frequency increment and then performing the phase calibration procedure again, until the scanning frequency being determined not lower than the maximum value.