Usb hub with multiple upstream-facing-ports and data transmission method thereof

An USB hub data transmission method comprising:

• providing an USB hub, wherein the USB hub comprises a first upstream-facing-port connector, a second upstream-facing-port connector, a plurality of downstream-facing-port connectors, a first hub controller, and a second hub controller, a first upstream-port of the first hub controller is coupled to the first upstream-facing-port connector, a first downstream-port of the first hub controller is coupled to a first downstream-facing-port connector among the downstream-facing-port connectors, a first upstream-port the second hub controller is coupled to the second upstream-facing-port connector, a first downstream-port of the second hub controller is coupled to a second downstream-facing-port connector among the downstream-facing-port connectors, and a communication terminal of the second hub controller is coupled to a communication terminal of the first hub controller;
• coupling a first host to the first upstream-facing-port connector;
• coupling an USB device to one of the downstream-facing-port connectors and controlled by the first host;
• coupling a second host to the second upstream-facing-port connector;
• determining whether the first hub controller or the second hub controller obtains mode control information;
• and
• in response to the mode control information obtained by the first hub controller or the second hub controller being that the USB device is required to be controlled by the second host, the USB device controlled by the first host switching to be controlled by the second host.