公开(公告)号：US20190087375A1

公开(公告)日：2019-03-21

申请号：US16002625

申请日：2018-06-07

Applicant: PROLIFIC TECHNOLOGY INC.

Inventor： Tien-Wei YU ,  Cheng-Sheng CHAN ,  Chun-Hsu CHEN ,  Ren-Jie DUAN

IPC: G06F13/40 ,  G06F13/42

CPC classification number: G06F13/4027 ,  G06F13/4282 ,  G06F13/4295 ,  G06F2213/0042

Abstract: A USB hub includes an upstream port; a first USB device control unit for performing packet format conversion; an FIFO circuit for storing data outputted from the first host; a second USB device control unit for performing packet format conversion; and a plurality of downstream ports. When any one of the downstream ports is coupled to the mobile device, if the first host commands the mobile device to switch to a host role from a device role, the mobile device temporarily disconnects from the USB hub, and the first host commands the USB hub to change an internal routing path. After the mobile device switches to the host role, the first host still performs the host role, and the first USB device control unit performs the device role; the mobile device performs the host role, and the second USB device control unit performs the device role.