#include<stdio.h>
unsigned int UART0_ADDR = 0x20080000;
unsigned int retu=0;
int i=0;
void delay_x(unsigned short cycles)
{    
    unsigned short t;
    t = cycles;
    while ( --t != 0 );
}
int  main()
{
///////////初始化部分////////////////////////////////////////////////////
    retu = *(unsigned int *)(UART0_ADDR  + 0X30);//uart_cr
    *(unsigned int *)(UART0_ADDR  + 0X30) = 0x300;
  //  retu = *(unsigned int *)(UART0_ADDR  + 0X24);//ibrd
  //  retu = *(unsigned int *)(UART0_ADDR  + 0X28);//fbrd
   *(unsigned int *)(UART0_ADDR  + 0X24) = 1;
   *(unsigned int *)(UART0_ADDR  + 0X28) = 40;
   *(unsigned int *)(UART0_ADDR  + 0X30) = 0x300;
    
   *(unsigned int *)(UART0_ADDR  + 0X2c) = 0x60;//UART_LCR_H
   *(unsigned int *)(UART0_ADDR  + 0X34) = 0x12; //UART_IFLS
   *(unsigned int *)(UART0_ADDR  + 0X38) = 0x0;//UART_IMSC
    
    
    retu = *(unsigned int *)(UART0_ADDR  + 0X30);//uart_cr
     
    *(unsigned int *)(UART0_ADDR  + 0X30) = retu | 0x01;//使能串口
//////////////////////////////////////////////////////////   
    while(1)
    {
   // retu = *(unsigned int *)(UART0_ADDR  + 0X18);
  //  retu = retu&0x40;
    if(((*(unsigned int *)(UART0_ADDR  + 0X18))&0x40)==0x40)
    {
        retu = *(unsigned int *)(UART0_ADDR  + 0X00);
        retu = retu&0xff;
        *(unsigned int *)(UART0_ADDR  + 0X00) = retu;
    }
    retu = 0;
    delay_x(0X7000);
    }
    return 0;
}