飞思卡尔单片机DZ60---SCI(查询接收)

#include <hidef.h> /* for EnableInterrupts macro */
#include "derivative.h" /* include peripheral declarations */

//整个功能：PC-单片机-PC，PC串口发数据-单片机串口接收数据-单片机将接收到的数据发送回给PC

#define LED_D1      PTDD_PTDD0
#define LED_D1_DIR  PTDDD_PTDDD0

#define LED_ON      0
#define LED_OFF     1

unsigned char SCANF_SEND_STRINGS[] = "HELLO MCU WORLD";
unsigned char *pSendString = SCANF_SEND_STRINGS;
unsigned char ReceiveString;

/*************************************************************/
/*                  初始化总线时钟PEE模式                    */
/*              外部晶振频率为4MHz，总线频率16MHz            */
/*************************************************************/
void INIT_MCG(void) 
{
  MCGC2=0x36;        
  while(!MCGSC_OSCINIT);     
  MCGC1=0xb8;
  while(MCGSC_IREFST);
  while(MCGSC_CLKST!=0b10);
  MCGC2_LP = 1;
  MCGC1 = 0x90;
  MCGC3 = 0x48;     
  MCGC2_LP = 0;
  while(!MCGSC_PLLST);
  while(!MCGSC_LOCK);
  MCGC1 = 0x10;
  while(MCGSC_CLKST!=0b11);
} 


//延时函数
void delay(void) 
{
  unsigned int i;
  unsigned int j;
   
   
  for(i = 0; i < 100; i++)
     for(j = 0; j < 4000; j++);
  
}


void main(void) {

  DisableInterrupts;
  SOPT1 = 0;
  INIT_MCG();
  EnableInterrupts; /* enable interrupts */
  /* include your code here */
  
  LED_D1_DIR = 1;
  LED_D1     = LED_OFF;
  
  
  
 //以下为设置波特率，以及初始化SCI1控制寄存器  
  SCI1BDH = 0X00;
  SCI1BDL = 0X68;//波特率设置为9600
  SCI1C1 = 0x00; //设置SCI1为正常模式，八位数据位，无奇偶校验
  SCI1C2 = 0x0C; //RE = 1(bit2)接收器打开
                 //TE = 1(bit3)发送器打开
 
 
  while(1)
  {
    while(!SCI1S1_RDRF);// SCI1S1_RDRF = 1时，表示接收数据寄存器满，可以取出数据
    SCI1S1_RDRF  = 0; //清除SCI1S1_RDRF
    ReceiveString = SCI1D; //将接收寄存器中的数据保存至ReceiveString
  //  LED_D1 = ~LED_D1;
   // delay();
    
    while(!SCI1S1_TDRE);//SCI1S1_TDRE = 1时，发送数据寄存器（缓存区）空，可以发送数据
    SCI1D = ReceiveString;//将接收到的数据，放至发送数据寄存器（缓存区），发送
  //  LED_D1 = ~LED_D1;
 //   delay();
         
  }
 
 
  for(;;) {
    __RESET_WATCHDOG(); /* feeds the dog */
  } /* loop forever */
  /* please make sure that you never leave main */
}
  

程序改成下面语句，上位机串口发大数据不死机，但可能丢数据。

  while(1)  
  {  
 /*  while(!SCI1S1_RDRF);// SCI1S1_RDRF = 1时，表示接收数据寄存器满，可以取出数据   
    SCI1S1_RDRF  = 0; //清除SCI1S1_RDRF   
    ReceiveString = SCI1D; //将接收寄存器中的数据保存至ReceiveString  
 
      
   while(!SCI1S1_TDRE);//SCI1S1_TDRE = 1时，发送数据寄存器（缓存区）空，可以发送数据   
   SCI1D = ReceiveString;//将接收到的数据，放至发送数据寄存器（缓存区），发送
*/
    if(SCI1S1_RDRF == 1) 
    {
       ReceiveString = SCI1D;
      if(SCI1S1_TDRE == 1) 
       {
           SCI1D = ReceiveString;
       } 

    }
  
           
  }