Patent ID: 8214678

Claim:
A serial data transfer apparatus that transmits and receives data with a destination apparatus via a serial bus, the serial data transfer apparatus comprising: a transport controller that performs a process of a transport layer; a link controller that performs a process of a link layer; and a physical layer circuit that performs a process of a physical layer, wherein the link controller outputs idle data to the physical layer circuit, the idle data being received from the destination apparatus, and stops an operation of a unit responsible for generating data to transmit to the destination apparatus while outputting the idle data to the physical layer circuit, and wherein the link controller comprises: a transmission process block that generates data to output to the destination apparatus via the physical layer circuit; a data storage unit; a first selector that selectively outputs at least one of an output of the transmission process block and an output of the data storage unit to the physical layer circuit; and a control block, wherein the control block comprises a detection circuit that detects whether reception data from the destination apparatus is idle data or not, in an idle period, the transmission process block continues to operate and the first selector selects the output of the transmission process block, the control block controls so that if the detection circuit detects that the reception data is the idle data, the data storage unit starts storing the reception data, after completing to store the reception data, the data storage unit outputs the reception data, which is stored by the data storage unit, to the first selector, the first selector selects the output of the data storage unit, and the transmission process block stops operating.