MSP430FR4133: ISR for

> #pragma vector=USCIAB1RX_VECTOR

Where did this vector name come from? I don't see it in msp430fr4133.h. (The G2 series had something like this. Is your MCU name set correctly in CCS?)

Anyway, I recommend:

> #pragma vector=USCI_A0_VECTOR

Thanks for the reply!

So we've decided to use the UART loopback example that texas instruments provides.

However, we still aren't able to get into the ISR.

We've modified the parameters according to the calculator here: http://software-dl.ti.com/msp430/msp430_public_sw/mcu/msp430/MSP430BaudRateConverter/index.html

Here's our code below:

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//******************************************************************************
//!  EUSCI_A0 External Loopback test using EUSCI_A_UART_init API
//!
//!  Description: This demo connects TX to RX of the MSP430 UART
//!  The example code shows proper initialization of registers
//!  and interrupts to receive and transmit data.
//!
//!  SMCLK = MCLK = BRCLK = DCOCLKDIV = ~1MHz, ACLK = 32.768kHz
//!
//!
//!           MSP430FR2xx_4xx Board
//!             -----------------
//!       RST -|          UCA0TXD|----|
//!            |                 |    |
//!            |                 |    |
//!            |          UCA0RXD|----|
//!            |                 |
//!
//! This example uses the following peripherals and I/O signals. You must
//! review these and change as needed for your own board:
//! - UART peripheral
//! - GPIO Port peripheral (for UART pins)
//! - UCA0TXD
//! - UCA0RXD
//!
//! This example uses the following interrupt handlers. To use this example
//! in your own application you must add these interrupt handlers to your
//! vector table.
//! - USCI_A0_VECTOR.
//******************************************************************************
#include "driverlib.h"
#include "Board.h"

uint16_t i;
uint8_t RXData = 0, TXData = 0;
uint8_t check = 0;


void conditionalBlink(){
    P4DIR |= 0x01;                          // Set P4.0 to output direction

     for(;;) {
         volatile unsigned int i;            // volatile to prevent optimization

         P4OUT ^= 0x01;                      // Toggle P4.0 using exclusive-OR

         i = 10000;                          // SW Delay
         do i--;
         while(i != 0);
     }
}

void main(void)
{
    //Stop Watchdog Timer
    WDT_A_hold(WDT_A_BASE);

    //Set ACLK = REFOCLK with clock divider of 1
    CS_initClockSignal(CS_ACLK,CS_REFOCLK_SELECT,CS_CLOCK_DIVIDER_1);
    //Set SMCLK = DCO with frequency divider of 1
    CS_initClockSignal(CS_SMCLK,CS_DCOCLKDIV_SELECT,CS_CLOCK_DIVIDER_1);
    //Set MCLK = DCO with frequency divider of 1
    CS_initClockSignal(CS_MCLK,CS_DCOCLKDIV_SELECT,CS_CLOCK_DIVIDER_1);

    //Configure UART pins
    GPIO_setAsPeripheralModuleFunctionInputPin(
        GPIO_PORT_UCA0TXD,
        GPIO_PIN_UCA0TXD,
        GPIO_FUNCTION_UCA0TXD
    );
    GPIO_setAsPeripheralModuleFunctionInputPin(
        GPIO_PORT_UCA0RXD,
        GPIO_PIN_UCA0RXD,
        GPIO_FUNCTION_UCA0RXD
    );

    /*
     * Disable the GPIO power-on default high-impedance mode to activate
     * previously configured port settings
     */
    PMM_unlockLPM5();

    //Configure UART
    //SMCLK = 1MHz, Baudrate = 115200
    //UCBRx = 8, UCBRFx = 0, UCBRSx = 0xD6, UCOS16 = 0
    EUSCI_A_UART_initParam param = {0};
    param.selectClockSource = EUSCI_A_UART_CLOCKSOURCE_SMCLK;
    param.clockPrescalar = 6;
    param.firstModReg = 8;
    param.secondModReg = 17;
    param.parity = EUSCI_A_UART_NO_PARITY;
    param.msborLsbFirst = EUSCI_A_UART_LSB_FIRST;
    param.numberofStopBits = EUSCI_A_UART_ONE_STOP_BIT;
    param.uartMode = EUSCI_A_UART_MODE;
    param.overSampling = EUSCI_A_UART_OVERSAMPLING_BAUDRATE_GENERATION;

    if (STATUS_FAIL == EUSCI_A_UART_init(EUSCI_A0_BASE, &param)) {
        return;
    }

    EUSCI_A_UART_enable(EUSCI_A0_BASE);

    EUSCI_A_UART_clearInterrupt(EUSCI_A0_BASE,
        EUSCI_A_UART_RECEIVE_INTERRUPT);

    // Enable USCI_A0 RX interrupt
    EUSCI_A_UART_enableInterrupt(EUSCI_A0_BASE,
        EUSCI_A_UART_RECEIVE_INTERRUPT);

    // Enable global interrupts
    __enable_interrupt();
    while (1)
    {
        // Increment TX data
        TXData = TXData+1;
        // Load data onto buffer
        EUSCI_A_UART_transmitData(EUSCI_A0_BASE, TXData);
        while(check != 1);
        check = 0;
    }
}
//******************************************************************************
//
//This is the USCI_A0 interrupt vector service routine.
//
//******************************************************************************
#if defined(__TI_COMPILER_VERSION__) || defined(__IAR_SYSTEMS_ICC__)
#pragma vector=USCI_A0_VECTOR
__interrupt
#elif defined(__GNUC__)
__attribute__((interrupt(USCI_A0_VECTOR)))
#endif
void EUSCI_A0_ISR(void)
{

    conditionalBlink();
    switch(__even_in_range(UCA0IV,USCI_UART_UCTXCPTIFG))
    {
        case USCI_NONE: break;
        case USCI_UART_UCRXIFG:
            RXData = EUSCI_A_UART_receiveData(EUSCI_A0_BASE);
            // Check value
            if(!(RXData == TXData))
            {
                while(1);
            }
            check =1;
            break;
       case USCI_UART_UCTXIFG: break;
       case USCI_UART_UCSTTIFG: break;
       case USCI_UART_UCTXCPTIFG: break;
    }
}

We've also realized that connecting the tx pin from our module to the tx pin of the board, we get  the correct value displayed on the serial output (putty serial Com port).

When we step through the code in debug mode, we don't get any value stored in the TX Buffer.

How are you doing the loopback? Are you connecting the RXD/TXD pins on J1 or on J101 (MCU side)? If you're using J1, have you removed the jumpers from the J101 RXD/TXD  pins?

Also, you should probably remove the jumper on JP1 (P1.0 LED).

Thanks for your advice,

So, all we have is a jumper that goes from the TXD of our RFID Reader, to the RXD of the MCU (Pin 1.1).

Is there any additional wiring that's needed ??, I'm not quite sure what you mean by removing the jumpers from the J101 RXD/TXD pins.

Thanks again.

When I saw the P4.0 LED, I supposed you were using the Launchpad, but looking back I see you never said that. What platform are you using?

The EM-18 data sheet I found said it runs at 5V (presumably logic as well). Does your platform have level shifters?

Anyway, I see you've restarted the discussion over at

https://e2e.ti.com/support/microcontrollers/msp430/f/166/t/821659