Patent ID: 7831794

Claim:
A memory card connectable to a host device, comprising: a plurality of bidirectional data lines for use in transferring data; a bidirectional command line for use in transferring a command from the host device; a command control circuit which receives the command and sends a response signal in serial via the bidirectional command line in response to either one of a rise edge and a fall edge of a clock signal, the response signal indicating that the memory card receives the command from the host device; and a data control circuit which transfers the data in parallel via the plurality of bidirectional data lines in response to both the rise edge and the fall edge of the clock signal, the data control circuit transferring the data in response to the command, wherein a first transfer operation of a command and a response signal is performed simultaneously with a second transfer operation of data during data write and data read, the first transfer operation being performed by the command control circuit via the bidirectional command line, the second transfer operation being performed by the data control circuit via the bidirectional data lines.