Answer:
Explanation:
#include "msp430g2553.h"
#define TXLED BIT0
#define RXLED BIT6
#define TXD BIT2
#define RXD BIT1
const char string[] = { "Hello World\r\n" };
unsigned int i; //Counter
int main(void)
{
WDTCTL = WDTPW + WDTHOLD; // Stop WDT
DCOCTL = 0; // Select lowest DCOx and MODx settings
BCSCTL1 = CALBC1_1MHZ; // Set DCO
DCOCTL = CALDCO_1MHZ;
P2DIR |= 0xFF; // All P2.x outputs
P2OUT &= 0x00; // All P2.x reset
P1SEL |= RXD + TXD ; // P1.1 = RXD, P1.2=TXD
P1SEL2 |= RXD + TXD ; // P1.1 = RXD, P1.2=TXD
P1DIR |= RXLED + TXLED;
P1OUT &= 0x00;
UCA0CTL1 |= UCSSEL_2; // SMCLK
UCA0BR0 = 0x08; // 1MHz 115200
UCA0BR1 = 0x00; // 1MHz 115200
UCA0MCTL = UCBRS2 + UCBRS0; // Modulation UCBRSx = 5
UCA0CTL1 &= ~UCSWRST; // **Initialize USCI state machine**
UC0IE |= UCA0RXIE; // Enable USCI_A0 RX interrupt
__bis_SR_register(CPUOFF + GIE); // Enter LPM0 w/ int until Byte RXed
while (1)
{ }
}
#pragma vector=USCIAB0TX_VECTOR
__interrupt void USCI0TX_ISR(void)
{
P1OUT |= TXLED;
UCA0TXBUF = string[i++]; // TX next character
if (i == sizeof string - 1) // TX over?
UC0IE &= ~UCA0TXIE; // Disable USCI_A0 TX interrupt
P1OUT &= ~TXLED; }
#pragma vector=USCIAB0RX_VECTOR
__interrupt void USCI0RX_ISR(void)
{
P1OUT |= RXLED;
if (UCA0RXBUF == 'a') // 'a' received?
{
i = 0;
UC0IE |= UCA0TXIE; // Enable USCI_A0 TX interrupt
UCA0TXBUF = string[i++];
}
P1OUT &= ~RXLED;
}
