DEVICE-SIDE CONTROLLER, HOST-SIDE CONTROLLER, COMMUNICATION CONTROLLER, USB SYSTEM, METHOD AND PROGRAM FOR PACKET-BASED COMMUNICATION, AND RECORDING MEDIUM

摘要

PROBLEM TO BE SOLVED: To provide a USB system capable of suppressing a decrease in communication efficiency even when a communication path slower than the USB standards is used.

SOLUTION: The host-side SM 32 of a host-side controller 11, when receiving a SOF packet transmitted from a host 10 to a device 13, avoids the transmission of the received SOF packet to a device side. The device-side SM 42 of a device-side controller 12 transmits the SOF packet to the device 13 at a predetermined interval after connection between the host 10 and device 13 has been established. This eliminates the need for SOF packet transmission between the controllers 11 and 12. Thus, a communication bandwidth between the controllers 11 and 12 of low communication speeds can be used only for packets other than the SOF packet. This increases communication efficiencies of these other packets.

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