LUFA (Lightweight USB fr a mework for AVRs) is my first foray into the world of USB. Originally based on the AT90USBKEY from Atmel, it is an open-source, driver for the USB-enabled AT90USBXXX AVR microcontroller series,

AT90USB646 pdf资料 AT90USB646自带usb端口-AT90USB646 pdf data AT90USB646 comes with usb port

AT90USB646芯片与上位机通过USB接口通信-AT90USB646 chip with the host computer via the USB interface communication