MSP430F149学习之路——UART

代码一：

 #include <msp430x14x.h>
 void int_clk()
 {
   BCSCTL1 &= ~XT2OFF;
   BCSCTL2 |= SELM_2 + SELS;
   do
   {
     IFG1 &= ~OFIFG;
     for(int i=;i<;i++)
       _NOP();
   }while((IFG1 & OFIFG)!=);
   IFG1 &= ~OFIFG;
 }
 void int_usart()
 {
   U0CTL |= SWRST;    //复位串口
   U0CTL |= CHAR;     //8位数据
   U0TCTL |= SSEL1;   //选择SMCLK
   //波特率19200
   U0BR1 = 0X01;
   U0BR0 = 0XA0;
   UMCTL0 = 0XC0;

   ME1 |= UTXE0 + URXE0;   //使能接收和发送
   U0CTL &= ~SWRST;        //清楚串口复位信号

   IE1 |= URXIE0;          //使能接收中断
   P3SEL |= BIT4 + BIT5;
   P3DIR |= BIT4;
 }
 void sent_byte(unsigned char data)
 {
   while((IFG1 & UTXIFG0)==);
   U0TXBUF = data;
 }
 #pragma vector=UART0RX_VECTOR
 __interrupt void UART0(void)
 {
   unsigned char data = ;
   data = U0RXBUF;
   sent_byte(data);
 }
 int main()
 {
   WDTCTL = WDTPW + WDTHOLD;
   int_clk();
   int_usart();
   _EINT();
   return ;
 }

代码二：

 #include <msp430x14x.h>
 void int_clk()
 {
   BCSCTL1 &= XT2OFF;
   BCSCTL2 |= SELS + SELM_2;
   do
   {
     IFG1 &= ~OFIFG;
     for(int i=;i<;i++)
       _NOP();
   }while((IFG1 & OFIFG)!=);
   IFG1 &= ~OFIFG;
 }
 void int_usart()
 {
   U0CTL |= SWRST;
   U0CTL |= CHAR;
   U0TCTL = SSEL1;
    //
   U0BR1 = 0X03;
   U0BR0 = 0X41;
   U0MCTL = 0X00;

   ME1 |= UTXE0 + URXE0;
   U0CTL &= ~SWRST;
   IE1 |= URXIE0;

   P3SEL |= BIT4 + BIT5;
   P3DIR |= BIT4;
 }
 void send_byte(unsigned char data)
 {
   while((IFG1 & UTXIFG0)==);
   U0TXBUF = data;
 }
 //串口0发送字符串函数
 /*void Print_Str(char *s)
 {
   while(*s != '\0')
   {
     send_byte(*s++);
   }
 }
 */
 #pragma vector=UART0RX_VECTOR
 __interrupt void UART0_RX_ISR(void)
 {
   unsigned char data;
   data = U0RXBUF;
   P6OUT = data;
   send_byte(data);
 }
 void main()
 {
   WDTCTL = WDTPW + WDTHOLD;
   P6DIR = 0XFF;
   P6OUT = 0XFF;
   int_clk();
   int_usart();
   _EINT();
 //  Print_Str("hello!\n");
 }