CCS/MSP430FR6972: msp430fr6972

unsigned char RxByte;
volatile unsigned char RxData[256];
unsigned char TxByte;
volatile unsigned int ir;

void irda();

int main(void)

{
WDTCTL = WDTPW | WDTHOLD; // stop watchdog timer

PJSEL0 = BIT4 | BIT5;
PJDIR = 0xFFFF;

// Configure GPIO
P3SEL0 |= BIT4 | BIT5; // irda operation
P3SEL1 &= ~(BIT4 | BIT5); //irda operation

 PM5CTL0 &= ~LOCKLPM5;

CSCTL0_H = CSKEY >> 8; // Unlock CS registers 
CSCTL1 = DCOFSEL_3; // Set DCO to 4MHz 
CSCTL2 = SELA__LFXTCLK | SELS__DCOCLK | SELM__DCOCLK; 
CSCTL3 = DIVA__1 | DIVS__1 | DIVM__1; // Set all dividers to 1 
CSCTL4 &= ~LFXTOFF; // Enable LFXT1 
do 
{ 
CSCTL5 &= ~LFXTOFFG; // Clear XT1 fault flag 
SFRIFG1 &= ~OFIFG; 
}while (SFRIFG1&OFIFG); // Test oscillator fault flag 
CSCTL0_H = 0; // Lock CS registers 


irda();

while(1)
{

for (ir=1000; ir; ir--); // Small delay
while(!(UCA1IFG & UCTXIFG));
UCA1TXBUF = TxByte;

__disable_interrupt();
UCA1IE |= UCRXIE; // Enable RX int

__bis_SR_register(GIE); // Enter interrupts

LCD[3] = lcd_num[5];
RxData[TxByte] = RxByte; // Store RXed character in RAM
LCD[2] = lcd_num[RxByte];
if (TxByte != RxByte)
{
LCD[0] = lcd_num[8];
while(1);
}
TxByte++;

}
// return 0;
}

void irda()
{
UCA1CTL1 |= UCSWRST;
UCA1CTL1 = UCSSEL_2;            //(0x0080)
UCA1BR0 = 26;
UCA1BR1 = 0;
UCA1MCTLW = UCBRF_1 + UCOS16;
UCA1IRTCTL = UCIRTXPL2 + UCIRTXPL0 + UCIRTXCLK + UCIREN;
UCA1CTL1 &= ~UCSWRST;
UCA1IE |= UCRXIE;
}

INTERRUPT PROGRAM  :

#pragma vector = USCI_A1_VECTOR
__interrupt void USCI_A1_ISR(void)
{
RxByte = UCA1RXBUF; // Get RXed character
UCA1IE &= ~UCRXIE;
}