Patent ID: 8872540

Claim:
A method of sharing in use an impedance matching circuit of a memory circuit to perform an initial calibration and a full time refresh mode calibration, wherein the impedance matching circuit comprises a pull-up driver and a pull-down driver, the method comprising: supplying power to the memory circuit; utilizing the pull-up driver and the pull-down driver of the impedance matching circuit to perform the initial calibration on the memory circuit to adjust slew rates of a logic-high voltage and a logic-low voltage of an output voltage of the memory circuit; the memory circuit exiting the initial calibration; the memory circuit entering a driving mode; the memory circuit exiting the driving mode every a predetermined interval; utilizing the pull-up driver and the pull-down driver of the impedance matching circuit to perform the full time refresh mode calibration on the memory circuit according to a refresh command after exiting the driving mode, wherein a self-refresh period does not exist between the full time refresh mode and the driving mode; an output voltage detection circuit of the memory circuit determining a level of the output voltage of the memory circuit; and utilizing the pull-up driver and the pull-down driver of the impedance matching circuit to adjust the level of the output voltage according to a determination result generated by the output voltage detection circuit, a low reference voltage, and a high reference voltage, wherein the low reference voltage is different from the high reference voltage, and the pull-up driver and the pull-down driver are coupled to an output terminal of the memory circuit.