interrupt[TPU_TGI0A] void EKLZ_SOFT_RS_INT(void)
{
  TPU_TSR0 = TPU_TSR0 & 0xFE;  //Clear INT Flag
 
  //IF 52us INT - dec a variables which will be used
  //for sending/recv @104us
  int_divider--;
  int_divider_rx--;
 
  //STOP BIT WAITING
  if ((!start_bit_detected) && !stop_bit_detected)// && !int_divider_rx)
    {
      if (PORT3.3 == 1)
        stop_bit_detected = true;
    }
 
  //USART RECEIVE/START BIT DETECTION
  if (!start_bit_detected && stop_bit_detected)  //HERE WE ARE @52 us INT
    {
      if (PORT3.3 == 0)  //START Bit detecting
        {
          TPU_TCNT0 = 0;  //this line for some delay
          start_bit_detected = 8; //8 -> for 8 bits reading
          stop_bit_detected = false;
          isu_rx_buffer = 0;
         
          int_divider_rx = 2;
        }
    }
  else//if (start_bit_detected)//USART RECEIVE
    {
      if (!int_divider_rx)
        {
          isu_rx_buffer >>= 1;
          if (PORT3.3)
            isu_rx_buffer |= 0x80;
          start_bit_detected--;
          if (!start_bit_detected)
            {
              isu_byte_received = true;
            }

          int_divider_rx = 2;
        }
    }
 
  //USART SEND
  if (isu_counter && !int_divider)
    {
      P3DR.4 = isu_buffer & 1;
      isu_buffer = isu_buffer >> 1;
      isu_counter--;
      int_divider = 2;
    }
}

byte INT_SOFT_USART_Data_Ready(void)
{
  return isu_byte_received;
}

byte INT_SOFT_USART_Write_Byte(byte data_to_send)
{
  if (!isu_counter)
    {
      isu_buffer = (data_to_send << 1) | 0x200;
      isu_counter = 10;
      int_divider = 2;
      return True;
    }
  return False;
}

byte INT_SOFT_USART_Read(void)
{
  isu_byte_received = False;
  return isu_rx_buffer;
}