承上启下继往开来，承的是U 盘/HUB，启的是UHCI/EHCI，抓住设备和驱动两条生命线， 讲述usb core 的故事。-Future nexus, the Order of the U disk/HUB Kai UHCI/EHCI, seize equipment and driving two lifelines, tells the story of usb core.

USB HUB测试专用，可用于自能化的测试环境中。-USB HUB test dedicated, can be used for intelligent test environment.