ex_2.c

89c52 t2定时器 串口波特率生产与应用

#include "reg52.h"
#define uint 	unsigned int
#define uchar   unsigned char
sbit RS485Flag =P1^0;
sbit dooralarm =P1^6;
sbit sw1       =P1^7;
/*void mDelay(uint DelayTime)
{
	uint i;
	for(;DelayTime>0;DelayTime--)
	{
		for(i=0;i<124;i++)
		{;}	
	}
}
*/
main()
{
		//T2设置
	RCLK=1;
	TCLK=1;//选用T2作为串口时钟
	T2CON=0x30;//选择定时方式
	TH2=0xFF;  //串口波特率为9600  11.0592MHz   
	TL2=0xB8;  //6MHz  4800  FFD9
	RCAP2H = 0xFF;
	RCAP2L = 0xB8;//11.0592MHz 4800  FFB8
	ET2=0;
    ES=1;  //串口中断允许
	PS=1;  //串口中断优先
	EA=1;  //总中断
	TR2=1; //启动T2

	//串口设置
	SCON=0x70;		//设置串口位方式1,SM2=1时，接受到有效的停止位，RI才置1
	PCON=0x00;

	RS485Flag=0;
	while(1)
	{
		SBUF=0xFF;
		while(TI==0);
		TI=0;
	}
}