Patent ID: 8856422

Claim:
A memory card controller for controlling a data transfer between a host apparatus which issues a read command to request the data transfer and a memory card to which a transfer size and a transfer start address of the data transfer is instructed when the memory card controller receives the read command, the memory card controller comprising: a serial interface operable to receive data output from the memory card serially, the serial interface not providing a clock signal for the data transfer to the memory card; a receiver operable to receive the read command from the host apparatus, the read command specifying the transfer size and the transfer start address of the data transfer; a flow controller operable to control the data transfer with the memory card by responding to a transfer authorization request from the memory card; a continuity determination unit operable to determine continuity between (i) a transfer end address specified by a previously received read command and (ii) a transfer start address specified by a next received read command received next in two read commands sequentially received from the host apparatus via the receiver; and a command controller operable to issue a transfer command to the memory card according to the read command, wherein when the receiver receives, from the host apparatus, a first read command specifying a transfer start address, and a transfer size, the command controller issues the transfer command to the memory card to (i) cause the memory card to start the data transfer, (ii) specify the transfer start address specified by the first read command and (iii) specify a predetermined transfer size that is larger than the transfer size specified by the first read command, thereby causing the memory card to perform the data transfer according to the transfer start address and the predetermined transfer size specified by the transfer command, when a size of the data transferred from the memory card to the host apparatus in response to the transfer command reaches the transfer size specified by the first read command, the command controller controls the flow controller to transmit a response representing a transfer busy state to the transfer authorization request from the memory card, thereby pausing a transfer operation of the memory card, and when the receiver receives a second read command specifying a transfer start address in a state that the transfer operation of the memory card is paused and the continuity determination unit determines that the transfer start address specified by the second read command is continuous with the transfer end address represented by the first read command, the command controller controls the flow controller to transmit a response representing a transfer ready state to the transfer authorization request from the memory card, thereby restarting the transfer operation of the memory card.