说明：  HT82K95E应用范例 详细的usb程序 HT82K95E datasheet
(HT82K95E datasheet Features
Operating voltage: fSYS=6M/12MHz: 3.3V~5.5V
Low voltage reset function
32 bidirectional I/O lines (max.)
8-bit programmable timer/event counter with overflow interrupt
16-bit programmable timer/event counter and overflow interrupts
Crystal oscillator (6MHz or 12MHz)
Watchdog Timer
PS2 and USB modes supported
USB 2.0 low speed function
3 endpoints supported (endpoint 0 included))