void main(void)
{
  WDTCTL = WDTPW + WDTHOLD;                 // Stop watchdog
  P3SEL = 0x30;                             // P3.3,4 = USART0 TXD/RXD
  U0CTL = SWRST;
  ME1 |= UTXE0 + URXE0;                     // Enabled USART0 TXD/RXD
  UCTL0 |= CHAR;                            // 8-bit character, SWRST=1
  UTCTL0 |= SSEL0;                          // UCLK = ACLK
  UBR00 = 0x03;                             // 9600 from 1Mhz
  UBR10 = 0x00;                             //
  UMCTL0 = 0x4A;                            // Modulation
  UCTL0 &= ~SWRST;                          // Initialize USART state machine
  IE1 |= URXIE0;                   // Enable USART0 RX interrupt
  IFG1 &= ~UTXIFG0;                         // Clear inital flag on POR
  _EINT();
  while(1){
       while ((IFG1 & UTXIFG0) == 0); //ждем пока буфер будет свободен
       TXBUF0 = 0x30;                       //отсылаем символ
  }
}
#pragma vector = USART0RX_VECTOR
__interrupt void RxD()
{
    char rec_char  = RXBUF0;
  
}