485中断收发数据问题，求帮助！！

jxmuestc · 发表于 2014-9-25 09:26:50

我写了个串口中断485收发数据的代码，外部发一帧数据主程序进行相应的操作。现在的情况是我的程序只能执行一次相应的操作。然后串口要发很多次命令我的程序才能响应一次。不知道问题出在哪儿，请大家帮忙看看，谢谢！
这是我的中断处理代码。

[mw_shl_code=c,true]void USART2_IRQHandler(void) { extern u8 Addr_Buffer[2]; extern u8 Command_Buffer[2]; extern u8 Con_len_Buffer[2]; extern u8 Content_Buffer[2]; extern u8 CheckSum_Buffer[2]; extern u8 Rec_Sucess_Flag; u8 data; u16 tmp; static u8 RecState=Head1; static u8 len=0; static u8 len_total=0; static u8 head1_flag=0; static u8 head2_flag=0; static u8 Addr_flag=0; static u8 Command_flag=0; static u8 Con_len_flag=0; static u8 CheckSum_flag=0; static u16 CheckSum=0; if(USART_GetITStatus(USART2, USART_IT_RXNE) != RESET) { /*Clear flag*/ USART_ClearITPendingBit(USART2,USART_IT_RXNE); data=USART_ReceiveData(USART2); switch(RecState) { case Head1: if(data==0xee) {head1_flag++;} if((data==0x19)&&(head1_flag==0x01)) { RecState=Head2; head1_flag=0x00; } break; case Head2: if(data==0xee) {head2_flag++;} if((data==0x19)&&(head2_flag==0x01)) { RecState=Addr; head2_flag=0x00; } break; case Addr: Addr_Buffer[Addr_flag]=data; CheckSum= CheckSum+ Addr_Buffer[Addr_flag]; Addr_flag++; if (Addr_flag==0x02) { RecState=Command; Addr_flag=0x00; } break; case Command: Command_Buffer[Command_flag]=data; CheckSum= CheckSum + Command_Buffer[Command_flag]; Command_flag++; if (Command_flag==0x02) { RecState=Con_len; Command_flag=0x00; } break; case Con_len: Con_len_Buffer[Con_len_flag]=data; CheckSum= CheckSum + Con_len_Buffer[Con_len_flag]; Con_len_flag++; if (Con_len_flag==0x02) { RecState=Content; Con_len_flag=0x00; } break; case Content: tmp=0x00; tmp= Con_len_Buffer[0]; tmp=tmp<<8; len_total= tmp|Con_len_Buffer[1]; if (len_total==0x00) { RecState=Check; len=0x00; } else { Content_Buffer[len]=data; CheckSum= CheckSum + Content_Buffer[len]; len++; if(len>=len_total) { RecState=Check; len=0x00; len_total=0x00; } } break; case Check: CheckSum_Buffer[CheckSum_flag]=data; CheckSum_flag++; if (CheckSum_flag==0x02) { tmp=0x00; tmp= CheckSum_Buffer[0]; tmp=tmp<<8; if(CheckSum==(tmp|CheckSum_Buffer[1])) { RecState=End1; CheckSum=0x00; CheckSum_flag=0x00; } } break; case End1: if (data==0x03) {RecState=End2;} break; case End2: if (data==0x03) { Rec_Sucess_Flag=TRUE; } RecState=Head1; break; default: RecState=Head1; break; } } }[/mw_shl_code]