| 摘要 |
PROBLEM TO BE SOLVED: To provide a data transfer control device, an electronic device, and a data transfer control method capable of enhancing the transfer efficiency in the case of aperiodic transfer. SOLUTION: When a first mode (mode with SOF (Star Of Frame)) is set, data are transferred while a SOF packet is transferred for a frame period, and when a second mode (mode without SOF) is set and aperiodic (bulk) transfer is conducted, the periodic transfer of the SOF packet is invalidated and aperiodic data are transferred. When no aperiodic data exist even when the second mode is set, the SOF packet are transferred for a frame period. In the case of host operations in compliance with the OTG (On-The-Go) standard of the USB (Universal Serial Bus), a pipe area is reserved to a packet buffer, the aperiodic data are automatically transferred while invalidating the period transfer of the SOF packet between the pipe area and an end point for the aperiodic transfer. When all automatic transfer instruction signals for the pipe area are deactivated, even when the second mode is set, the SOF packet is periodically transferred. COPYRIGHT: (C)2004,JPO
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