A memory controller including a first transmittal module, a clock pin, a second transmittal module, a first control module and a second control module is disclosed. The first transmittal module includes a specific pin. The clock pin receives a clock signal. The first transmittal module and the clock pin constitute an embedded multimedia card (eMMC) interface. The second transmittal module and the clock pin constitute a universal flash storage (UFS) interface. The first control module communicates with an external host via the first transmittal module according to the clock signal when a level of the specific pin is at a first level. The second control module communicates with the external host via the second transmittal module according to the clock signal when the level of the specific pin is at a second level. The first level exceeds the second level.