设置串口，最关键的是波特率的设置，推荐一个网站，很方便地计算波特率，http://software-dl.ti.com/msp430/msp430_public_sw/mcu/msp430/MSP430BaudRateConverter/index.html
1 P3SEL |= (BIT4 + BIT5); // P3.4,5 = USCI_A0 TXD/RXD 2 UCA0CTL1 |= UCSWRST; // **Put state machine in reset** 3 UCA0CTL1 |= UCSSEL_2; // CLK = SMCLK 4 UCA0BR0 = 26; // 24MHz/57600=26,1,0,1 5 UCA0BR1 = 0; // 6 UCA0MCTL = UCBRF_1+UCBRS_0+UCOS16; // Modulation UCBRSx=0, UCBRFx=0,UCOS16 = 1 7 UCA0CTL1 &= ~UCSWRST; // **Initialize USCI state machine** 8 UCA0IE |= UCRXIE; // Enable USCI_A0 RX interrupt
#pragma vector=USCI_A0_VECTOR __interrupt void USCI_A0_ISR(void) { switch(__even_in_range(UCA0IV,4)) { case 0:break; case 2:break; case 4:break; default:break; } }
关键就是UCA0IV 寄存器，通过看文档得知，这是 USCI_Ax Interrupt Vector Register，具体功能如下：
00h = No interrupt pending，0是无中断
02h = Interrupt Source: Data received; Interrupt Flag: UCRXIFG; Interrupt
Priority: Highest，2是数据接收触发中断
04h = Interrupt Source: Transmit buffer empty; Interrupt Flag: UCTXIFG;
Interrupt Priority: Lowest，4是数据发送中断
经常使用的是接收中断，没用过发送中断