NA
add timer3 related files for setting period interrupt
add timer3.c and timer3.h searching path
NA
include timer3.h
call timer3 initialization function and adding interrupt function
read out USB Rx data in timer3 interrupt function
use if to determine the USB data is ready or not
change Rx FIFO size, test if the fifo buffer could be bigger to fit Ymodem-1k
clear while() loop in main()
restor USB Rx FIFO size into 128, set this macro into 1024 could lead USB error