外部中断计数器实验
..................\EX1_INT
..................\EX1_INT.c
..................\EX1_INT.hex
..................\EX1_INT.lnp
..................\EX1_INT.LST
..................\EX1_INT.M51
..................\EX1_INT.OBJ
..................\EX1_INT.Opt
..................\EX1_INT.plg
..................\EX1_INT.Uv2
..................\EX1_INT_Opt.Bak
..................\EX1_INT_Uv2.Bak
..................\STARTUP.A51