Hwi Interrupt on Sitara AM3359 (TMDXICE3359)

Void taskFxn(UArg a0, UArg a1)
{
    char t_str[32];
    // Enable DMTimer3
                /* This function will enable clocks for the DMTimer3 instance */
                DMTimer3ModuleClkConfig();
                /* Load the counter with the initial count value */
                DMTimerCounterSet(SOC_DMTIMER_3_REGS, TIMER_INITIAL_COUNT);
                /* Load the load register with the reload count value */
                DMTimerReloadSet(SOC_DMTIMER_3_REGS, TIMER_RLD_COUNT);
                /* Configure the DMTimer for Auto-reload and compare mode */
                DMTimerModeConfigure(SOC_DMTIMER_3_REGS, DMTIMER_AUTORLD_NOCMP_ENABLE);
                DMTimerIntEnable(SOC_DMTIMER_3_REGS, DMTIMER_INT_OVF_EN_FLAG);
                DMTimerEnable(SOC_DMTIMER_3_REGS);

    while(1)
    {
        Task_sleep(250);
        UARTPutString(uartInstance,t_str);
    }
}
Void main()
{
    Hwi_Params hwiParams;

    Task_Handle task;
    Error_Block eb;

    System_printf("enter main() \n");

    // Initialize memory
    mmuInit(applMmuEntries);

    // Pin muxing
    AM335X_INDCOMM_MUX iceMux[] = {
        // SPI1 pinmux
        { 0x0994 , 3 , AM335X_PIN_OUTPUT },    //    spi1_d0_mux2/SIMO    mcasp0_fsx
        { 0x0998 , 3 , AM335X_PIN_INPUT_PULLUP },    //    spi1_d1_mux2/SOMI    mcasp0_axr0
        { 0x0990 , 3 , AM335X_PIN_OUTPUT | AM335X_PIN_INPUT_PULLDOWN },    //    spi1_sclk_mux2/CLK    mcasp0_aclkx . IMPORTATN: You need to enable both, input and output. Input clock is feed back into the RX logic of SPI.
        { 0x099c , 7 , AM335X_PIN_OUTPUT },    //    spi1_cs0_mux4: HVS SPI1 CS in GPIO mode
        { 0x09A0 , 7 , AM335X_PIN_OUTPUT },    //    gpio3[18]    mcasp0_aclkr -> INDUS_LDn
        {0xFFFFFFFF,0,0}
    };
    PINMUX_Config(iceMux);

    // Enable Outputs Leds
    led_init();
    // Enable Industrial Inputs
    spiInit();


    Error_init(&eb);
    task = Task_create(taskFxn, NULL, &eb);
    if (task == NULL) {
        System_printf("Task_create() failed!\n");
        BIOS_exit(0);
    }

    Hwi_Params_init(&hwiParams);
    hwiParams.arg = SYS_INT_TINT3;
    hwiParams.priority = 0;
    hwiParams.enableInt = FALSE;
    Hwi_create(SYS_INT_TINT3, DMTimerIsr, &hwiParams, NULL);
    Hwi_enableInterrupt(SYS_INT_TINT3);

    UartOpen(uartInstance, NULL);

    BIOS_start();     /* enable interrupts and start SYS/BIOS */
}
Void DMTimerIsr(UArg arg)
{
    /* Disable the DMTimer interrupts */
    DMTimerIntDisable(SOC_DMTIMER_3_REGS, DMTIMER_INT_OVF_EN_FLAG);

    /* Clear the status of the interrupt flags */
    DMTimerIntStatusClear(SOC_DMTIMER_3_REGS, DMTIMER_INT_OVF_IT_FLAG);

    UARTPutString(uartInstance,"We are in DMTimerIsr!\n");

    /* Enable the DMTimer interrupts */
    DMTimerIntEnable(SOC_DMTIMER_3_REGS, DMTIMER_INT_OVF_EN_FLAG);
}