状态机串口接收中断，switch&case语句，break后无法直接跳出？

yanse1214 · 发表于 2014-10-26 17:47:27

写了个状态机接收中断的程序。但是在switch --case..语句中。判断完ｃａｓｅ　１　，ｂｒｅａｋ后。老是先跳到　ｃａｓｅ２１　的ｂｒｅａｋ．然后才会跳到末尾的ｄｅｆａｕｌｔ中。　为什么呢。　程序看了几遍。都不知道哪里错了。　
程序如下：
void USART_GetData()
{
   u8 mychar=0;

   mychar=USART1->DR;

   switch(receiveState)
     {

   case 0:             //
         if(mychar==0x40)
      {
                                                         receiveState=1;

   ByteCount=0;
   checksum=0;


      }
      else
{
   receiveState=0;//状态机复位
}
         break;

   case 1:       //设备地址头高4位
         if(mychar==HexToAscii(SLAVE_ID>>4))
      {
         receiveState=2;
   checksum^=mychar;
      }
   else
{
   receiveState=0;//状态机复位
}
      break;
   case 2:       //设备地址头低4位
         if(mychar==HexToAscii(SLAVE_ID&0x0f))
      {
         receiveState=3;
   checksum^=mychar;
      }
   else
{
   receiveState=0;//状态机复位
}
      break;

      case 3:
if(mychar==0x41) //命令&标志
{
receiveState=4;
checksum^=mychar;
}
else
{
   receiveState=0;
}
      break;
case 4://到这个位置，读写分离
{
switch(mychar) //读命令
   { case 0x30:

        receiveState=5;
   checksum^=mychar;
   //printf("\r\nthat is %x",mychar);

break;

case 0x31:    //写命令
   receiveState=14;
   checksum^=mychar;

      break;
            default:
   receiveState=0;
      break;
     }
}
      break;
/*Read command*/
case 5://读命令30 数据地址
   if(mychar==0x30)
     {
        receiveState=6;
   checksum^=mychar;
   //  printf("\r\nthat is %x",mychar);
     }
   else
     {
        receiveState=0;
     }
      break;
case 6: //30
   if(mychar==0x30)
     {
        receiveState=7;
   checksum^=mychar;
//  printf("\r\nthat is %x",checksum);
     }
   else
     {
        receiveState=0;
     }
      break;
case 7: //4 //from this ,dynamic & static
      {
   switch(mychar)
   { case 0x43:
receiveState=8;
   checksum^=mychar;
   g_cmd=1; //动态读标志
break;

case 0x44:

   receiveState=11;
   checksum^=mychar;

   g_cmd=2;  //静态读标志
      break;
            default:
   receiveState=0;
      break;
   }
}
      break;
/*A:DYNAMIC READ*/

case 8: //dynamic
   if(mychar==0x30)//30动态读低4位
      {
         receiveState=9;
   checksum^=mychar;
   // printf("\r\nthat is %x",mychar);
      }
   else
{
   receiveState=0;

}
      break;
      case 9:  //动态读数据长度判断高4位
        if(mychar==0x31)
        {
           receiveState=10;
   checksum^=mychar;
   ByteCount=AsciiToHex(mychar);
// printf("\r\nthat is %x",mychar);

      }
   else
{
   receiveState=0;
}
      break;
   case 10:  //动态读数据长度判断低4位
        if(mychar==0x32)
        {
           receiveState=44;//转到校验判断程序
   checksum^=mychar;
   ByteCount<<=4;
   ByteCount+=AsciiToHex(mychar);

      }
   else
{
   receiveState=0;
}
      break;
         /*B:STATIC READ*/
            case 11:
           //static
   if(mychar==0x32)//30静态读低4位
      {
         receiveState=12;
   checksum^=mychar;
      }
   else
{
   receiveState=0;
}
      break;
      case 12:  //静态读数据长度判断高4位
        if(mychar==0x31)
        {
           receiveState=13;
   checksum^=mychar;
   ByteCount=AsciiToHex(mychar);
//printf("\r\nthat is %x",mychar);
      }
   else
{
   receiveState=0;
}
      break;
   case 13:  //静态读数据长度判断低4位
        if(mychar==0x30)
        {
           receiveState=44;//转到校验判断程序
   checksum^=mychar;
   ByteCount<<=4;
   //printf("\r\nthat isfist %x",ByteCount);
   ByteCount+=AsciiToHex(mychar);
// printf("\r\nthat is %x",checksum);OK
      }
   else
{
   receiveState=0;
}
      break;
   /*Write command*/
   case 14:
     //写命令30 数据地址
   if(mychar==0x30)
     {
        receiveState=15;
   checksum^=mychar;
     }
   else
     {
        receiveState=0;
     }
      break;
case 15: //30
   if(mychar==0x30)
     {
        receiveState=16;
   checksum^=mychar;
   // printf("\r\nthe eveis%x",checksum);OK
     }
   else
     {
        receiveState=0;
     }
      break;
   case 16:
                   {
     switch(mychar) //清零地址(累积量)
     {
        case 0x43:
     receiveState=17;
   checksum^=mychar;
   g_cmd=4;  //清零标志位
break;

   case 0x44: //各个参数写地址

            receiveState=21;
checksum^=mychar;
         break;
case 0x45://测零功能调用地址
            receiveState=40;
checksum^=mychar;

      break;
   default:
        receiveState=0;
      break;
     }
     }
      break;
   case 17:
        if(mychar==0x45) //清零开始
        {
           receiveState=18;
   checksum^=mychar;
     }
        else
     {
        receiveState=0;
     }
      break;
   case 18:  //清零(累积量)的字节数，高4位
         if(mychar==0x30)
        {
           receiveState=19;
   checksum^=mychar;
   ByteCount=AsciiToHex(mychar);
   ByteCount<<=4;

     }
        else
     {
        receiveState=0;

     }
      break;
   case 19:  //清零(累积量)的字节数，低4位
         if(mychar==0x34)
        {
           receiveState=43;
   checksum^=mychar;
   ByteCount+=AsciiToHex(mychar);
//  printf("\r\nthe clearsumis%x",checksum);//OK
     }
        else
     {
        receiveState=0;
     }
      break;

case 21:  //写参数各个系数数据地址末4位
         {
   switch(mychar)  //写系数
           {

   case 0x32:
              receiveState=22;
   checksum^=mychar;
   g_cmd=5;//系数标志位
   break;

   case 0x36: //写恒定速度

         receiveState=25;
   checksum^=mychar;
   g_cmd=6; //速度标志位
              break;
   case 0x38: //写流量限值

         receiveState=28;
   checksum^=mychar;
   g_cmd=7; //流量限值标志位
            break;
   case 0x41: //写零点

         receiveState=31;
   checksum^=mychar;
   g_cmd=8;//静态零点标志位
            break;
               case 0x43: //写测零时间

         receiveState=34;
   checksum^=mychar;
   g_cmd=9; //测零时间标志位
         break;
            case 0x45: //写空态界限

         receiveState=37;
   checksum^=mychar;
   g_cmd=10;//空态界限标志位
            break;

   default:
        receiveState=0;
   break;
   }
     }
   break;                                     //程序老是先跳到了这里，然后再跳到末尾。为什么呢？哪里错了？
   case 22:  //具体写系数的字节数长度  高4位
      if(mychar==0x30)
        {
           receiveState=23;
   checksum^=mychar;
   ByteCount=AsciiToHex(mychar);
   ByteCount<<=4;

     }
        else
     {
        receiveState=0;

     }
      break;
   case 23:  //写系数的字节数长度，低4位
         if(mychar==0x34)
        {
           receiveState=43;
   checksum^=mychar;
   ByteCount+=AsciiToHex(mychar);
     }
        else
     {
        receiveState=0;
   // printf("OK");
     }
      break;

   case 25:  //具体写速度的字节数长度  高4位
      if(mychar==0x30)
        {
           receiveState=26;
   checksum^=mychar;
   ByteCount=AsciiToHex(mychar);
   ByteCount<<=4;

     }
        else
     {
        receiveState=0;

     }
      break;
   case 26:  //写速度的字节数长度，低4位
         if(mychar==0x32)
        {
           receiveState=43;
   checksum^=mychar;
   ByteCount+=AsciiToHex(mychar);
     }
        else
     {
        receiveState=0;
     }
      break;

case 28:  //具体写流量限值的字节数长度  高4位
      if(mychar==0x30)
        {
           receiveState=29;
   checksum^=mychar;
   ByteCount=AsciiToHex(mychar);
   ByteCount<<=4;

     }
        else
     {
        receiveState=0;

     }
      break;
   case 29:  //写流量限值的字节数长度，低4位
         if(mychar==0x32)
        {
           receiveState=43;
   checksum^=mychar;
   ByteCount+=AsciiToHex(mychar);
     }
        else
     {
        receiveState=0;
     }
      break;

   case 31:  //具体写零点的字节数长度  高4位
      if(mychar==0x30)
        {
           receiveState=32;
   checksum^=mychar;
   ByteCount=AsciiToHex(mychar);
   ByteCount<<=4;

     }
        else
     {
        receiveState=0;

     }
      break;
   case 32:  //写零点的字节数长度，低4位
         if(mychar==0x32)
        {
           receiveState=43;
   checksum^=mychar;
   ByteCount+=AsciiToHex(mychar);
     }
        else
     {
        receiveState=0;
     }
      break;

   case 34:
        //具体写测零时间的字节数长度  高4位
      if(mychar==0x30)
        {
           receiveState=35;
   checksum^=mychar;
   ByteCount=AsciiToHex(mychar);
   ByteCount<<=4;

     }
        else
     {
        receiveState=0;

     }
      break;
   case 35:  //写测零时间的字节数长度，低4位
         if(mychar==0x32)
        {
           receiveState=43;
   checksum^=mychar;
   ByteCount+=AsciiToHex(mychar);
     }
        else
     {
        receiveState=0;
     }
      break;

   case 37:
   //具体写空态界限的字节数长度  高4位
      if(mychar==0x30)
        {
           receiveState=38;
   checksum^=mychar;
   ByteCount=AsciiToHex(mychar);
   ByteCount<<=4;

     }
        else
     {
        receiveState=0;

     }
      break;
   case 38:  //写空态界限的字节数长度，低4位
         if(mychar==0x32)
        {
           //receiveState=39;
      receiveState=43;
   checksum^=mychar;
   ByteCount+=AsciiToHex(mychar);
     }
        else
     {
        receiveState=0;
     }
      break;

/***************测零与CPU复位功能的调用*******************/
case 40:
        if(mychar==0x30)
        {
           receiveState=41;
   checksum^=mychar;
     }
        else
     {
        receiveState=0;
     }
      break;
   //此处是为了增加测零与CPU复位功能的区别而修改
         case 41:  //测零(累积量)的字节数,30 32
         if(mychar==0x30)
        {
           receiveState=42;
   checksum^=mychar;


     }
        else
     {
        receiveState=0;

     }
      break;
   case 42:  //测零(累积量)的字节数，30 32
         if(mychar==0x32)
        {
           receiveState=47;
   checksum^=mychar;

     }
        else
     {
        receiveState=0;
     }
      break;

         case 47:
      if(mychar==0x30)
        {
           receiveState=48;
   checksum^=mychar;

     }
        else
     {
        receiveState=0;
     }
      break;
      case 48:
      if(mychar==0x30)
        {
           receiveState=49;
   checksum^=mychar;

     }
        else
     {
        receiveState=0;
     }
      break;
case 49:
      if(mychar==0x30)
        {
           receiveState=50;
   checksum^=mychar;

     }
        else
     {
        receiveState=0;
     }
      break;
case 50:

      {
switch(mychar)  //表明调用的是测零功能。
        {
        case 0x31:
         g_cmd=3;//测零标志位
        receiveState=44;
   checksum^=mychar;
         break;

      case 0x32:

   g_cmd=11;  // cpu复位标志位
           receiveState=44;
   checksum^=mychar;
   break;
default:
   receiveState=0;
   break;
}
}
   break;

  /**************数据接收端*******************/
   case 43:
   USART_Rx_Buffer[USART_Rx_ptr_in++]=mychar;

checksum^=mychar;

if(USART_Rx_ptr_in==(ByteCount<<1))  //当协议中，数据长度为定长时。
{
                        receiveState=44;

}
   break;

/***********CRC&END*************************/
   case 44: //动态读命令的异或校验值得比较
         if((HexToAscii(checksum>>4))==mychar)//higt 4 bit
         {
         receiveState=45;
      }
   else
{
//Error();//
      USART_Rx_Buffer_Clear();
receiveState=0;

}
      break;
   case 45: //动态读命令的异或校验值得比较
         if((HexToAscii(checksum&0x0f))==mychar)//low 4 bit
         {
         receiveState=46;//下一步就是帧的结束位
         }
   else
{
//Error();
USART_Rx_Buffer_Clear();
receiveState=0;

}
      break;

   case 46:
           if(mychar==0x0D)
           {


Analyze_command();


           }

      USART_Rx_Buffer_Clear();
        receiveState=0;

   break;
   default:
            break;
     }


}

sunliezhi · 发表于 2014-10-26 18:41:02

先不管问题在哪，先改成这样再试试：

case  xx:
{
      .......
      break;
}

lusson · 发表于 2014-10-26 18:53:00

应该是优化问题，因为所有的break都是做的同一件事，就是goto xxx
所以你在调试的时候可能就跑到那个break了。没问题的。

状态机串口接收中断，switch&case语句，break后无法直接跳出？

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