TM4C123GH6PM: Hibernation in Tm4c123gh6pm

I am trying the hibernation code in tm4c123gh6pm. but my code does not go in hibernation. I set current at 62mA  in hibernation this current should decrease but in my code, it is not happening. 

I want to connect VBAT to 3.3v so that this code will go in hibernation but ther is no VBAT pin on the board.

#include <stdint.h>
#include <stdbool.h>
#include "utils/ustdlib.h"
#include "inc/hw_types.h"
#include "inc/hw_memmap.h"
#include "driverlib/sysctl.h"
#include "driverlib/pin_map.h"
#include "driverlib/debug.h"
#include "driverlib/hibernate.h"
#include "driverlib/gpio.h"
#include "driverlib/sysctl.h"
#include "inc/hw_hibernate.h"

int main(void)
{
SysCtlClockSet(SYSCTL_SYSDIV_5|SYSCTL_USE_PLL|SYSCTL_XTAL_16MHZ|SYSCTL_OSC_MAIN);
SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOF);
GPIOPinTypeGPIOOutput(GPIO_PORTF_BASE, GPIO_PIN_1|GPIO_PIN_2|GPIO_PIN_3);

GPIOPinWrite(GPIO_PORTF_BASE,GPIO_PIN_1|GPIO_PIN_2|GPIO_PIN_3, 0x08);

SysCtlPeripheralEnable(SYSCTL_PERIPH_HIBERNATE);
HibernateEnableExpClk(SysCtlClockGet());
HibernateGPIORetentionEnable();
SysCtlDelay(64000000);

HibernateWakeSet(HIBERNATE_WAKE_PIN);
GPIOPinWrite(GPIO_PORTF_BASE,GPIO_PIN_3, 0x00);
HibernateRequest();

while(1)
{
}
}