MSP430F5438A的串口

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