USB-HID study notes -001

• USB basics first day
  • USB2.0 is divided into a low speed mode (1.5Mb / S) full-speed (12Mb / s) high-speed mode (480Mb / s). Synchronization with token checksum. Bit stuffing. Packet gap actual reach this speed .　
  • Encoding NRZI
  • USB insert identification process
    • 　　First identified as full-speed devices
    • Devices that are confirmed by the hub and converted to full-speed device