Patent ID: 8924678

Claim:
A storage device couplable to a host, comprising: a command line; a plurality of data lines; a clock line; a nonvolatile memory; and a controller coupled to the command line, the data lines and the clock line, wherein: the controller is configured to receive a clock signal through the clock line; the controller is configured to receive data and output a first response through the data lines, in accordance with a single edge transfer based on either one of a rise edge and a fall edge of the clock signal, in a first transfer mode; the controller is configured to receive data and output a first response through the data lines, in accordance with a double edge transfer based on both the rise edge and the fall edge of the clock signal, in a second transfer mode; the controller is configured to receive a first command and output a second response through the command line, in accordance with the single edge transfer; the controller is configured to switch between the first transfer mode and the second transfer mode in response to the first command; the controller is configured to receive the first command of the command line with the single edge transfer while transferring data of the data lines with the single edge transfer in the first transfer mode and in response to the first command to switch transferring data of the data line to the double edge transfer in the second transfer mode; the controller is configured to perform the double edge transfer through the data lines simultaneously with the single edge transfer through the command line; the controller is configured to receive a second command and output a third response through the command line, in accordance with the single edge transfer; and the controller is configured to receive the second command of the command line while transferring data of the data lines, the second command being used for informing the storage device that the host stops transferring data of the data line; and a transfer rate of the double edge transfer is higher than a transfer rate of the single edge transfer.