串行通信  接收发送
..................\4
..................\4.bak
..................\4.c
..................\4.hex
..................\4.lnp
..................\4.LST
..................\4.M51
..................\4.OBJ
..................\4.plg
..................\4.uvopt
..................\4.uvproj
..................\4_uvopt.bak
..................\4_uvproj.bak
..................\STARTUP.A51
..................\STARTUP.LST
..................\STARTUP.OBJ