msp4784 serial port

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msp4784 serial port [Copy link]

I am a novice, and I have some questions when I ask for guidance from experts:

#include "msp430x47x4.h"
void usart();
void main(void)
{
WDTCTL = WDTPW+WDTHOLD; // Stop WDT
FLL_CTL0 |= XCAP14PF; // Configure load caps
TACTL= TASSEL_1+ID_3 + MC_1+TACLR; // Select ACLK as the clock source of timer A, divide by 8, up counting mode
CCTL0 = CCIE; // Enable CCR0 interrupt
CCR0 = 2047; // Set period 0.5
usart();
P2DIR=0x02;
_EINT();
for(;;)
{
_BIS_SR(CPUOFF);
_NOP();
}

}
void usart(void)
{
UCA0CTL0 |= UCSWRST;
UCA0CTL0 |= UCSSEL_1; // CLK = ACLK，32768HZ
UCA0BR0 = 0x03; // 9600
UCA0BR1 = 0x00; //
UCA0MCTL = 0x4A; // Modulation
P2SEL |= 0x30; // P2.4,5 = USCI_A0 RXD/TXD
P2DIR|=0x10;
IE2=UCA0RXIE+UCA0TXIE;
UCA0CTL0 &= ~UCSWRST; // **Initialize USCI state machine**
}

// Echo back RXed character, confirm TX buffer is ready first
#pragma vector=TIMERA0_VECTOR
__interrupt void Timer_A (void)
{
P2OUT^=0x02;
//while ((IFG2 & UCA0TXIFG) == 0);
UCA0TXBUF =0x01; // TX -> RXed character

}

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What's the problem? Describe the phenomenon.

manmanroad

The serial debugging assistant shows garbled characters before the program is run. Even if debugging is stopped, the serial debugging assistant keeps receiving data. A similar situation occurs when another version of the serial debugging assistant is used. The crystal oscillator is tested and is normal.