Patent ID: 7447976

Claim:
A data transfer apparatus comprising: a first data transfer apparatus including: a first unit packet processing unit for generating a unit packet which is a USB packet and has a predetermined structure including a first data area by describing data which is taken as an object of transfer in the first data area; and a first isochronous packet processing unit for generating an isochronous packet which is a packet used in USB isochronous transfer and has a predetermined structure including a second data area by incorporating at least one unit packet into the second data area, and for isochronously transferring the isochronous packet to a second data transfer apparatus over a USB interface; a second data transfer apparatus including: a second isochronous packet processing unit for receiving the isochronous packet isochronously transferred from the first data transfer apparatus over the USB interface, and retrieving at least one unit packet incorporated into the second data area; and a second unit packet processing unit for retrieving data which is taken as an object of transfer from the first data area included in the unit packet; and a USB interface connecting the first and second data transfer apparatuses, wherein the unit packet further includes a first error check area for description of information for an error check of the unit packet; the isochronous packet further includes a second error check area for description of information for an error check of the isochronous packet; and the second unit packet processing unit makes an error check on the retrieved data which is taken as an object of transfer using the information in the first error check area.