求一段STC89C52单片机c语言程序，要求能通过串口通信由电脑向单片机发送数据，当发送的数据和前一个不一

#include "reg52.h" #define uchar unsigned char #define uint unsigned int //--------------------------------------------------- sbit led = P1^0; sbit key = P0^0; sbit out1= P0^1; sbit out2= P0^2; uint run_cnt; uchar te