Concerto M3 Timer Interrupt causing UART Failure

Hello,

I'm developing an application on the concerto ControlCARD (F28M35H52C1) and I'm having trouble with the UART when I have a timer interrupt trigger. When I comment out the TimerEnable function, the UART runs fine. Any ideas? Here's my code for the UART and timers.

// global variable for timer
static unsigned long g_dwTickCounter50mS = 0;
static unsigned long g_dwTickCounter1mS = 0;

    // within main function
    

    unsigned long    dwOldTickCounter1ms = 0;
    // Initialize the UART.
    //
    SysCtlPeripheralEnable(SYSCTL_PERIPH_UART0);
    GPIOPinTypeUART(GPIO_PORTE_BASE, GPIO_PIN_4 | GPIO_PIN_5);
    GPIOPinConfigure(GPIO_PE4_U0RX);
    GPIOPinConfigure(GPIO_PE5_U0TX);

    // Enable the Watchdog Timer
    //
    SysCtlPeripheralEnable(SYSCTL_PERIPH_WDOG0);

    //
    // Enable the system timers
    //
    SysCtlPeripheralEnable(SYSCTL_PERIPH_TIMER0);
    SysCtlPeripheralEnable(SYSCTL_PERIPH_TIMER1);

    // Configure the two 32-bit periodic timers.
    TimerConfigure(TIMER0_BASE, TIMER_CFG_32_BIT_PER);
    TimerConfigure(TIMER1_BASE, TIMER_CFG_32_BIT_PER);
    TimerLoadSet(TIMER0_BASE, TIMER_A, SysCtlClockGet(SYSTEM_CLOCK_SPEED)/10000);
    TimerLoadSet(TIMER1_BASE, TIMER_A, SysCtlClockGet(SYSTEM_CLOCK_SPEED)/5);

    // Setup the interrupts for the timer timeouts.
    IntEnable(INT_TIMER0A);
    IntEnable(INT_TIMER1A);
    TimerIntEnable(TIMER0_BASE, TIMER_TIMA_TIMEOUT);
    TimerIntEnable(TIMER1_BASE, TIMER_TIMA_TIMEOUT);

    // stall the timers during a breakpoint
    TimerControlStall(TIMER0_BASE, TIMER_A, true);
    TimerControlStall(TIMER1_BASE, TIMER_A, true);

    // configure the watchdog timer
    WatchdogResetEnable(WATCHDOG0_BASE);
    WatchdogReloadSet(WATCHDOG0_BASE, SysCtlClockGet(SYSTEM_CLOCK_SPEED)*2); // 2 second timeout
    WatchdogStallEnable(WATCHDOG0_BASE);

    // Enable the timers.
    TimerEnable(TIMER0_BASE, TIMER_A);
    TimerEnable(TIMER1_BASE, TIMER_A);

    // Enable the watchdog timer
    WatchdogEnable(WATCHDOG0_BASE);

    UARTStdioInit(0);

    UARTprintf("UART Operating\n");

    while(1)
    {
    	// *** 200Hz loop ***
	if((g_dwTickCounter1mS - dwOldTickCounter1mS) > 5)
	{
	// save the 1 msec counter value
	    dwOldTickCounter1mS = g_dwTickCounter1mS;

	}

            UARTprintf("Program in while loop\n");         

// reload the watchdog
	WatchdogReloadSet(WATCHDOG0_BASE, SysCtlClockGet(SYSTEM_CLOCK_SPEED)*2);	// 2 second timeout
    }


//********************************************
// timer interrupt handlers

//*****************************************************************************
//
// The interrupt handler for the first timer interrupt.
//
//*****************************************************************************
void
Timer0IntHandler(void)
{
    // Clear the timer interrupt.
    TimerIntClear(TIMER0_BASE, TIMER_TIMA_TIMEOUT);

    // Toggle the flag for the first timer.
    HWREGBITW(&g_ulFlags, 0) ^= 1;

	// hit the watchdog
    watchDogHit();

	// increment the time counter
	g_dwTickCounter1mS++;
}

//*****************************************************************************
//
// The interrupt handler for the second timer interrupt.
//
//*****************************************************************************
void Timer1IntHandler(void)
{
    // Clear the timer interrupt.
    TimerIntClear(TIMER1_BASE, TIMER_TIMA_TIMEOUT);

	// increment the time counter
	g_dwTickCounter50mS++;

}

inline void watchDogHit(void)
{
	static uint8_t extWD = 0;

	// hit the external timer
	extWD ^= 1;
}

 

//Print out from UART Terminal:

UART Operating
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The UART garbage output happens after the timer interrupt occurs and then the application is unresponsive.

I appreciate your help.

Thanks,

Will