MSP430FR5969 UART overrun problem

up

I guess you mean the ‘UCOE’ bit, this is the Receiver overrun, probably you receive the transmitted data back and you don’t read ‘UCAxRXBUF’.

You have enabled ‘UCRXIE’ but I don’t see and ISR for it. In the Receiver_ISR you can read UCAxRXBUF.

thx you for your answer,

to read what is there in the register I put directly

unsigned char receive []=UCA1RXBUF

this is what I understood

#include "driverlib.h"
unsigned char TCU_HCI_RESET_REQ[4] = {0x01, 0x03, 0x0c, 0x00};

void main(void) {          
          P2SEL1 |= BIT5| BIT6;                    // Configure UART pins
      P2SEL0 &= ~(BIT5| BIT6);

      // Disable the GPIO power-on default high-impedance mode to activate
      // previously configured port settings
      PM5CTL0 &= ~LOCKLPM5;

      // Startup clock system with max DCO setting ~8MHz
      CSCTL0_H = CSKEY >> 8;                    // Unlock clock registers
      CSCTL1 = DCOFSEL_3 | DCORSEL;             // Set DCO to 8MHz
      CSCTL2 = SELA__VLOCLK | SELS__DCOCLK | SELM__DCOCLK;
      CSCTL3 = DIVA__1 | DIVS__1 | DIVM__1;     // Set all dividers
      CSCTL0_H = 0  ;                           // Lock CS registers

      // Configure USCI_A1 for UART mode
      UCA1CTLW0 = UCSWRST;                      // Put eUSCI in reset
      UCA1CTLW0 |= UCSSEL__SMCLK;               // CLK = SMCLK
      UCA1BR0 = 4;                             // 8000000/16/115200
      UCA1BR1 = 0x00;
      UCA1MCTLW |=0x55; //UCOS16 | UCBRF_1;
      UCA1CTLW0 &= ~UCSWRST;                    // Initialize eUSCI
      UCA1IE |= UCRXIE;                         // Enable USCI_A0 RX interrupt

          
          USART1_SendData(TCU_HCI_RESET_REQ,4);
          while(1);
}
void USART1_SendByte (unsigned char data) {
    while(!(UCA1IFG & UCTXIFG));
    UCA1TXBUF = data;
   __bis_SR_register(CPUOFF + GIE); // Enter LPM0 w/ int until Byte RXed
}
void USART1_SendData (unsigned char data[], unsigned char length) {

    unsigned char i;

for(i=0; i<length; i++) {
USART1_SendByte(data[i]);
}

}
#pragma vector=USCIAB0RX_VECTOR 
__interrupt void USCI0RX_ISR(void) 
{ 
usigned char receive[]=UCA1RXBUF;
}

You can’t use an Array that way, just use “usigned char receive = UCA1RXBUF;”.