51单片机模拟串口C语言程序代码

#include "string.h"

#include"stdio.h"

#include

sfr16 DPTR = 0x82;

typedef unsigned char INT8U;

typedef unsigned int INT16U;

typedef unsigned char uint8_t;

typedef unsigned int uint16_t;

typedef unsigned int uchar;

typedef unsigned char byte;

typedef unsigned int word;

#define YES 1

#define NO 0

//定义使用哪个定时器, 只可定义一个

#define TIMER_0

//#define TIMER_1

//定义串口收、发送管脚。

sbit rs_TXD = P2^1;

sbit rs_RXD = P2^0;

//根据定时器确定参数

#ifdef TIMER_0

#define TMOD_AND_WORD 0xF0;

#define TMOD_TIME_MODE 0x01;

#define TMOD_COUNT_MODE 0x05; //设置计数模式位

sbit TCON_ENABLE_TIMER = TCON^4;

sbit TCON_TFx = TCON^5; //中断标志位

sbit IE_ETx = IE^1; //中断允许位为 ET0

sbit IP_PTx = IP^1; //中断优先级

sfr rs_timerL = 0x8A; //TL0

sfr rs_timerH = 0x8C; //TH0

#endif

#ifdef TIMER_1

#define TMOD_AND_WORD 0x0F;

#define TMOD_TIME_MODE 0x10;

#define TMOD_COUNT_MODE 0x50; //设置计数模式位

sbit TCON_ENABLE_TIMER = TCON^6; //

sbit TCON_TFx = TCON^7; //中断标志位

sbit IE_ETx = IE^3; //中断允许位为 ET1

sbit IP_PTx = IP^4; //中断优先级

sfr rs_timerL = 0x8B; //TL1

sfr rs_timerH = 0x8D; //TH1

#endif

INT8U bdata rs_BUF; //串行收、发时用的移位暂存器。

sbit rs_BUF_bit7 = rs_BUF^7; //移位暂存器的最高位。

INT8U rs_shift_count; //移位计数器。

INT8U bdata rsFlags;

sbit rs_f_TI = rsFlags^0; //0:正在发送; 1: 一个字符完毕

sbit rs_f_RI_enable = rsFlags^1; //0:禁止接收; 1:允许接收

sbit rs_f_TI_enable = rsFlags^2; //0:禁止发送; 1:允许发送

//选择以下一个晶体频率

//#define Fosc 6000000 //6MHz

#define Fosc 11059200 //11.059MHz

//#define Fosc 12000000

//#define Fosc 18432000

//#define Fosc 20000000

//#define Fosc 24000000

//#define Fosc 30000000

//#define Fosc 40000000

//选择以下一个波特率:

//#efine Baud 300 //11.059MHz时，baud 最低为 300

//#define Baud 1200

//#define Baud 2400

//#define Baud 4800

#define Baud 9600

//#define Baud 14400

//#define Baud 19200

//#define Baud 28800

//#define Baud 38400

//#define Baud 57600

//收、发一位所需定时器计数

#define rs_FULL_BIT0 ((Fosc/12) / Baud)

#define rs_FULL_BIT (65536 - rs_FULL_BIT0)

#define rs_FULL_BIT_H rs_FULL_BIT >> 8 //收、发一位所需定时器计数高位

#define rs_FULL_BIT_L (rs_FULL_BIT & 0x00FF) //收、发一位所需定时器计数低位

//检测起始位的时间间隔所需定时器计数

#define rs_TEST0 rs_FULL_BIT0 / 4 //波特率较低时可以除以 3 或除以 2

#define rs_TEST ((~rs_TEST0))

#define rs_TEST_H rs_TEST >> 8 //高位

#define rs_TEST_L rs_TEST & 0x00FF //低位

//发送起始位所需定时器总计数

#define rs_START_BIT 0xFFFF - (Fosc/12/Baud) + 0x28

#define rs_START_BIT_H rs_START_BIT >> 8 //发送起始位所需定时器计数高位

#define rs_START_BIT_L rs_START_BIT & 0x00FF //发送起始位所需定时器计数低位

#define rs_RECEIVE_MAX 32 //最大接收长度

INT8U idata rs232buffer[rs_RECEIVE_MAX]; //收、发缓冲区

INT16U ReceivePoint; //接收数据存储指针

void soft_rs232_interrupt( void );

#ifdef TIMER_0

void timer0 (void) interrupt 1 using 3

{

if (rs_RXD == 0 | rs_shift_count > 0)

{ soft_rs232_interrupt(); }

else

{

rs_timerH = rs_TEST_H;

rs_timerL = rs_TEST_L;

}

}

#endif

#ifdef TIMER_1

void timer1 (void) interrupt 3 using 3

{

if (rs_RXD == 0 | rs_shift_count > 0)

{ soft_rs232_interrupt(); }

else

{

rs_timerH = rs_TEST_H;

rs_timerL = rs_TEST_L;

}

}

#endif

void soft_rs232_init (void) //串口初始化

{

TCON_ENABLE_TIMER = 0; //停止定时器

TMOD &= TMOD_AND_WORD;

TMOD |= TMOD_TIME_MODE;

rs_RXD = 1; //接收脚置成高电平

rs_TXD = 1; //发射脚置成高电平

IP_PTx = 1; //置中断优先级为高

IE_ETx = 1; //允许定时器中断

}

void soft_receive_init() //监测起始位

{

TCON_ENABLE_TIMER = 0; //停止定时器

rs_timerH = rs_TEST_H;

rs_timerL = rs_TEST_L;

rs_shift_count = 0;

TCON_ENABLE_TIMER = 1; //启动定时器