RTOS/EK-TM4C129EXL: Scheduling with Timer Interrupts

Part Number: EK-TM4C129EXL

Tool/software: TI-RTOS

I am working with timer module. I configured the timer using XGCONF. ISR Function is to toggle the state of LED for every 1 second. LED tends to glow continuously instead of blinking for 1 second. I couldn't able to find the problem in the code. 

/*
 *  ======== empty_min.c ========
 */

/* XDCtools Header files */

//----------------------------------------
// BIOS header files
//----------------------------------------

#include <xdc/std.h>  						
#include <ti/sysbios/BIOS.h> 				
#include <xdc/runtime/Log.h>				
#include <xdc/cfg/global.h> 				


//------------------------------------------
// TivaWare Header Files
//------------------------------------------

#include <stdint.h>
#include <stdbool.h>
#include "inc/hw_types.h"
#include "inc/hw_memmap.h"
#include "driverlib/sysctl.h"
#include "driverlib/gpio.h"
#include "inc/hw_ints.h"
#include "driverlib/interrupt.h"
#include "driverlib/timer.h"




/* BIOS Header files */
#include <ti/sysbios/BIOS.h>
#include <ti/sysbios/knl/Task.h>
/* TI-RTOS Header files */

#include <ti/drivers/GPIO.h>


/* Board Header file */
#include "Board.h"

#define TASKSTACKSIZE   128


Task_Struct task0Struct;
Char task0Stack[TASKSTACKSIZE];
void Timer_ISR(void);


/*
 *  ======== heartBeatFxn ========
 *  Toggle the Board_LED0. The Task_sleep is determined by arg0 which
 *  is configured for the heartBeat Task instance.
 */
Void heartBeatFxn()    // This is ISR function
{ 
     GPIO_toggle(Board_LED0);	
}

 /*
  *  ======== main ========
  */
int main(void)
{
    Task_Params taskParams;
    /* Call board init functions */

    Board_initGeneral();
    Board_initGPIO();
  

    /* Construct heartBeat Task  thread */
    Task_Params_init(&taskParams);
    taskParams.stackSize = TASKSTACKSIZE;
    taskParams.stack = &task0Stack;
    Task_construct(&task0Struct, (Task_FuncPtr)heartBeatFxn, &taskParams, NULL);


    /* Turn on user LED  */
    GPIO_write(Board_LED0, Board_LED_ON);
      

    /* Start BIOS */
    BIOS_start();

    return (0);
}