Serial port programming

Serial port programming
Before the serial port works , It should be initialized , It mainly sets the timer for generating baud rate 1、 Serial port control and interrupt control . The specific steps are as follows :
determine T1 How it works ( Programming TMOD register ) Calculation T1 Initial value of , load TH1、TL1;
start-up T1( Programming TCON Medium TR1 position ). Determine the serial port control ( Programming SCON register );
When the serial port works in interrupt mode , To set the interrupt ( Programmer Zheng E IP register ).

#include "reg52.h" // This file defines some special function registers of MCU 

typedef unsigned int u16;	  // Declare and define data types 
typedef unsigned char u8;


/******************************************************************************* *  Function name  :UsartInit() *  The functionality  : Set the serial port  *  Input  :  nothing  *  Output  :  nothing  *******************************************************************************/
void UsartInit()
{
    
	SCON=0X50;			// Set to work 1
	TMOD=0X20;			// Set the working mode of the counter 2
	PCON=0X80;			// Double baud rate 
	TH1=0XF3;				// The initial value of the counter is set , Note that the baud rate is 4800 Of 
	TL1=0XF3;
	ES=1;						// Turn on receive interrupt 
	EA=1;						// Open total interrupt 
	TR1=1;					// Turn on the counter 
}

/******************************************************************************* *  Letter   Count   name  : main *  The functionality  :  The main function  *  transport   Enter into  :  nothing  *  transport   Out  :  nothing  *******************************************************************************/
void main()
{
    	
	UsartInit();  //  Serial initialization 
	while(1);		
}

/******************************************************************************* *  Function name  : Usart() interrupt 4 *  The functionality  :  Serial communication interrupt function  *  Input  :  nothing  *  Output  :  nothing  *******************************************************************************/
void Usart() interrupt 4
{
    
	u8 receiveData;

	receiveData=SBUF;// Go out and receive the data 
	RI = 0;// Clear the receive interrupt flag bit 
	SBUF=receiveData;// Put the received data into the transmit register 
	while(!TI);			 // Wait for the sending data to complete 
	TI=0;						 // Clear the transmission completion flag bit 
}