RTOS/MSP432E401Y: Receive data interrupt not triggering for UART

Part Number: MSP432E401Y

Tool/software: TI-RTOS

Hi,

I am using MSP432E401 launchpad.

I have configured UART2 and UART3 for sending and receiving data at 9600 baud

I am able to send data and could see it on connector pin using signal analyzer.

I have then looped back RX -- TX in my connector to loop the character sent back to rx.

Again, I could see my signal analyzer showing the plot.

Here, I have enabled the interrupt for receiving any data on my UART but it does not get trigger until I call UART_read();

Isn't the interrupt expected without even calling UART_read since I have enabled it?

Attached is the code, if I comment UART_read in function "testGsmUart" it does not callback my uartDataReadCallBack function.

Is there anything wrong in I configuring the UART?

Appreciate any pointers to resolve the problem.

#include <ti/drivers/UART.h>
#include <ti/sysbios/knl/Queue.h>

#include <Board.h>


#include "GSMModule.h"

static UART_Handle gsmUARTHandle;

static void uartDataReadCallBack(UART_Handle handle, void *buf, size_t count);
static void uartDataWriteCallBack(UART_Handle handle, void *buf, size_t count);

static void processGsmResponse();
static void initGsmModule();

Queue_Handle rxDataQ;

typedef struct gsmRxDataStruct{
    Queue_Elem elem;
    char data;
}gsmRxDataStruct;

gsmRxDataStruct gsmRxData;


/*
 *  ======== GSM Module thread ========
 *  This thread processes all the request and response from the gsm module
 */
void *GsmModuleThread()
{
    initGsmModule();

    //sleep(2);

    while (1) {

        processGsmResponse();

    }

}


void initGsmModule()
{

    rxDataQ = Queue_create(NULL, NULL);

    UART_init();

// Initialize UART parameters
    UART_Params params;
    UART_Params_init(&params);
    params.baudRate = 9600;
    //params.readMode = UART_MODE_BLOCKING;
    //params.writeMode = UART_MODE_BLOCKING;
    params.readMode = UART_MODE_CALLBACK;
    params.writeMode = UART_MODE_CALLBACK;
    params.readTimeout = UART_WAIT_FOREVER;
    params.writeTimeout = UART_WAIT_FOREVER;
    params.readEcho = UART_ECHO_OFF;

    params.readCallback = uartDataReadCallBack;
    params.writeCallback = uartDataWriteCallBack;

    // Open the UART
    gsmUARTHandle = UART_open(Board_UART2, &params);
    //gsmUARTHandle = UART_open(Board_UART3, &params);

    if(gsmUARTHandle == NULL)
    {
        //Failed to open UART
        while(1);
    }
}

void processGsmResponse()
{
    gsmRxDataStruct *d;

    if(!Queue_empty(rxDataQ))
    {
        d = Queue_get(rxDataQ);
        if(d)
        {
            char c = d->data;
        }
    }
}

void testGsmUart()
{
    char buffer = 'A';

    UART_write(gsmUARTHandle, &buffer, 1);

#if 1
    char* rd;
    /* SP_DEBUG: Needs this line else data receive interrupt is not triggering */
    UART_read(gsmUARTHandle, rd, 1);
#endif
}

void uartDataReadCallBack(UART_Handle handle, void *buf, size_t count)
{
    char *rxBuf = (char*) buf;

    gsmRxDataStruct rData;
    rData.data = rxBuf[0];

    Queue_put(rxDataQ, &(rData.elem));
}

void uartDataWriteCallBack(UART_Handle handle, void *buf, size_t count)
{

}

My UART configuration as follows

/* UART configuration structure */
const UARTMSP432E4_HWAttrs uartMSP432E4HWAttrs[MSP_EXP432E401Y_UARTCOUNT] = {
    {
        .baseAddr = UART3_BASE,
        .intNum = INT_UART3,
        .intPriority = (~0),
        .flowControl = UARTMSP432E4_FLOWCTRL_NONE,
        .ringBufPtr  = uartMSP432E4RingBuffer[MSP_EXP432E401Y_UART3],
        .ringBufSize = sizeof(uartMSP432E4RingBuffer[MSP_EXP432E401Y_UART3]),
        .rxPin = UARTMSP432E4_PA4_U3RX,
        .txPin = UARTMSP432E4_PA5_U3TX,
        .ctsPin = UARTMSP432E4_PIN_UNASSIGNED,
        .rtsPin = UARTMSP432E4_PIN_UNASSIGNED,
        .errorFxn = NULL
    },
    {
        .baseAddr = UART2_BASE,
        .intNum = INT_UART2,
        .intPriority = (~0),
        .flowControl = UARTMSP432E4_FLOWCTRL_NONE,
        .ringBufPtr  = uartMSP432E4RingBuffer[MSP_EXP432E401Y_UART2],
        .ringBufSize = sizeof(uartMSP432E4RingBuffer[MSP_EXP432E401Y_UART2]),
        .rxPin = UARTMSP432E4_PD4_U2RX,
        .txPin = UARTMSP432E4_PD5_U2TX,
        .ctsPin = UARTMSP432E4_PIN_UNASSIGNED,
        .rtsPin = UARTMSP432E4_PIN_UNASSIGNED,
        .errorFxn = NULL
    }
};

const UART_Config UART_config[MSP_EXP432E401Y_UARTCOUNT] = {
    {
        .fxnTablePtr = &UARTMSP432E4_fxnTable,
        .object = &uartMSP432E4Objects[MSP_EXP432E401Y_UART3],
        .hwAttrs = &uartMSP432E4HWAttrs[MSP_EXP432E401Y_UART3]
    },
    {
        .fxnTablePtr = &UARTMSP432E4_fxnTable,
        .object = &uartMSP432E4Objects[MSP_EXP432E401Y_UART2],
        .hwAttrs = &uartMSP432E4HWAttrs[MSP_EXP432E401Y_UART2]
    }
};

const uint_least8_t UART_count = MSP_EXP432E401Y_UARTCOUNT;