EK-TM4C1294XL: Timer4A exception

Here is a simple program on the EK-TM4C1294XL. The timer 4A ISR fires and I can halt in the ISR.

When I stop the program, the registers show exception 4F. What does this mean?

Thanks,

Priya

uint32_t g_ui32SysClock;
int main(void)
{

    g_ui32SysClock =  SysCtlClockFreqSet((SYSCTL_XTAL_25MHZ |
                                                     SYSCTL_OSC_MAIN |
                                                     SYSCTL_USE_PLL |
                                                     SYSCTL_CFG_VCO_480), 120000000);
    CommandCheckTimerInit();
    while(1);

}
    void CommandCheckTimerInit(void)
    {
                        SysCtlPeripheralEnable(SYSCTL_PERIPH_TIMER4);
                        IntMasterEnable();
                        TimerConfigure(TIMER4_BASE, TIMER_CFG_A_PERIODIC);

                        //Initialise the Timer
                        TimerLoadSet(TIMER4_BASE, TIMER_A, g_ui32SysClock/40);    //PN 25 ms timer

                        //Setup the interrupts for the timer timeouts.
                        IntEnable(INT_TIMER4A);
                        TimerIntEnable(TIMER4_BASE, TIMER_TIMA_TIMEOUT);

                        //Enable the timers.
                        TimerEnable(TIMER4_BASE, TIMER_A);
    }

    void CommandCheckTimer_ISR (void)
    {
        static uint8_t countMotor = 0;
        static uint8_t countTherm = 0;

        TimerIntClear(TIMER4_BASE, TIMER_TIMB_TIMEOUT);

        countMotor++;
        countTherm++;
        if (countMotor == 3){
           countMotor = 0;
        }
        if (countTherm == 40){
           countTherm = 0;
        }

}