AT89c51与pc通讯设计，keil和vb语言编写，测试通过

//打开串口调试程序，将波特率设置为2400，无奇偶校验 #include <REG52.H> /* special function register declarations */ /* for the intended 8051 derivative */ #include <stdio.h> /* prototype declarations for I/O functions */ #ifdef MONITOR51 /* Debugging with Monitor-51 needs */ char code reserve [3] _at_ 0x23; /* space for serial interrupt if */ #endif /* Stop Exection with Serial Intr. */ /* is enabled */ sbit KEY=P3^2; void delay(unsigned int U) { while(--U); } /*------------------------------------------------ The main C function. Program execution starts here after stack initialization. ------------------------------------------------*/ void main (void) { /*------------------------------------------------ Setup the serial port for 1200 baud at 11.0592MHz. ------------------------------------------------*/ #ifndef MONITOR51 SCON = 0x50; /* SCON: mode 1, 8-bit UART, enable rcvr */ TMOD |= 0x20; /* TMOD: timer 1, mode 2, 8-bit reload */ TH1 = 0xf3; /* TH1: reload value for 2400 baud @ 12MHz */ TR1 = 1; /* TR1: timer 1 run */ TI = 1; /* TI: set TI to send first char of UART */ #endif /*------------------------------------------------ Note that an embedded program never exits (because there is no operating system to return to). It must loop and execute forever. ------------------------------------------------*/ while (1) { if(!KEY) { delay(10000); if(!KEY) { printf ("This programer test ok!\n"); printf ("12:25:26\n"); } } } }