#include <msp430.h>
/**
* main.c
*/
int main(void)
{
WDTCTL = WDTPW + WDTHOLD; // Stop WDT
FLL_CTL0 |= XCAP18PF; // Configure load caps
P2SEL |= 0x30; // P2.4,5 = USART0 TXD/RXD
ME1 |= UTXE0 + URXE0; // Enable USART0 TXD/RXD
UCTL0 |= CHAR; // 8-bit character
// UTCTL0 |= SSEL1; // UCLK = SMCLK
// UBR00 = 0x6D; // 1MHz 9600
// UBR10 = 0x00; // 1MHz 9600
// UMCTL0 = 0x03; // modulation
UTCTL0 |= SSEL0;
UBR00 = 0x03;
UBR10 = 0x00;
UMCTL0 = 0x4A;
UCTL0 &= ~SWRST; // Initialize USART state machine
IE1 |= URXIE0; // Enable USART0 RX interrupt
P2DIR |= 0x10; // P2.4 output direction
while (!(IFG1 & UTXIFG0));
TXBUF0 = 'H';
while (!(IFG1 & UTXIFG0));
TXBUF0 = 'E';
while (!(IFG1 & UTXIFG0));
TXBUF0 = 'L';
while (!(IFG1 & UTXIFG0));
TXBUF0 = 'L';
while (!(IFG1 & UTXIFG0));
TXBUF0 = 'O';
__bis_SR_register(LPM0_bits + GIE); // Enter LPM0 w/ interrup
//while(1);
}
#if defined(__TI_COMPILER_VERSION__) || defined(__IAR_SYSTEMS_ICC__)
#pragma vector=USART0RX_VECTOR
__interrupt void usart0_rx (void)
#elif defined(__GNUC__)
void __attribute__ ((interrupt(USART0RX_VECTOR))) usart0_rx (void)
#else
#error Compiler not supported!
#endif
{
while (!(IFG1 & UTXIFG0)); // USART0 TX buffer ready?
TXBUF0 = RXBUF0; // RXBUF0 to TXBUF0
}
把程序下载 MSP430F437 的单片机上 ，然后PC的串口工具先接收到 HELLO ,然后不停的接收 到 LOLOL0... ...