A system for accessing a memory card is provided. The system includes a control unit having a control pin and a processor. The processor senses a card-insertion signal from a socket via the control pin for indicating whether the memory card has been inserted into the socket. The processor provides a power control signal via the control pin to supply an operating voltage to the memory card when the sensed card-insertion signal indicates that the memory card has been inserted into the socket. The processor detects whether a write protection function of the memory card is present via the control pin.