Микроконтроллеры

/**
*
*    @brief    hwi_USCI_A0_Fxn
*    
*    @details  Interrupt function UART 0(USCI_A0)
*
*              RX - Put the char to the internal UART RX buf, if no room - overflow
*              TX - Get char from the internal TX buf and put it to the UART TX register
*                   If TX buf is empty, disables TX interrupt and post the TX semaphore  
*
*    @param [in]  arg  The SYS/BYOS default parameter
*    
*    @pre      May be used only like Interrupt Handler function for 
*              the UART 0(USCI_A0) hardware interrupt 
*
*/
void hwi_USCI_A0_Fxn(UArg arg)                    //!< Int N 56 
{
  
#if defined USE_UART_0  
   //!< UCRXIFG is automatically reset when UCAxRXBUF is read
   //!< UCTXIFG is automatically reset if a character is written to UCxTXBUF
   volatile int rx_val;
   UART_ST * pdata =  &p_uart_globals->g_uart0_data;
   
   switch(__even_in_range(UCA0IV,4))
   {
      case 0: 
        
         break;                          //!< Vector 0 - no interrupt
         
      case 2:                            //!< Vector 2 - RXIFG
        
         rx_val = UCA0RXBUF;    //!< read any case 
         if(UCA0STAT & (UCFE | UCOE | UCRXERR)) //!< if rx error
         {
            //!< do nothing here
         }
         else
         {
            //!< check 'fifo is full'
            if((pdata->rx_head == pdata->rx_tail - 1) ||
                 (pdata->rx_head == pdata->rx_buf_size - 1 && pdata->rx_tail == 0))
            {
                 //!< overflow
               pdata->rx_buf[pdata->rx_head] = rx_val;
               pdata->rx_head++;
               if(pdata->rx_head >= pdata->rx_buf_size)
                  pdata->rx_head = 0;

               pdata->rx_tail = pdata->rx_head + 1;
               if(pdata->rx_tail >= pdata->rx_buf_size)
                  pdata->rx_tail = 0;
            }
            else //!< no overflow
            {
               pdata->rx_buf[pdata->rx_head] = rx_val;
               pdata->rx_head++;
               if(pdata->rx_head >= pdata->rx_buf_size)
                  pdata->rx_head = 0;
            }
         } 
         break;
         
      case 4:                                  //!< Vector 4 - TXIFG
        
         if(pdata->tx_idx >= pdata->tx_cnt)    //!< tx overall buf finished
         {  
            UCA0IE &=  ~UCTXIE; 
            pdata->tx_buf = NULL;
            
            Semaphore_post(semTxUart0);
         }
         else
         {  
            if(pdata->tx_buf)
               UCA0TXBUF = pdata->tx_buf[pdata->tx_idx++]; //!< send char out UART transmitter
         }
         break;
         
      default: 
         break;
  }
#endif  /* #if defined USE_UART_0  */
}