EFM32 in Energy Mode EM1 for Blinking LEDs using TIMER0

blink-EM1.c

#include "efm32.h"
#include "em_chip.h"
#include "em_cmu.h"
#include "em_emu.h"
#include "em_gpio.h"
#include "em_timer.h"
#include "em_system.h"

void _exit(int code)///New lib SysCall for GCC
{
  while(1);
}
void TIMER0_IRQHandler(void)
{ 
  /* Clear flag for TIMER0 overflow interrupt */
  TIMER_IntClear(TIMER0, TIMER_IF_OF);
  
  /* Toggle LED ON/OFF */
  GPIO_PinOutToggle(gpioPortE,2);
}
int main(void)
{
  // Initialize chip 
  CHIP_Init();
  
  // Enable the External Oscillator and Wati till it stabilizes
  CMU_OscillatorEnable(cmuOsc_HFXO,true,true);  
  
  // Set the HFXO as the Clock Source
  CMU_ClockSelectSet(cmuClock_HF, cmuSelect_HFXO);
  
  //Disable the HFRCO
  CMU_OscillatorEnable(cmuOsc_HFRCO, false, false);  
  
  //Now We are through with setting the clock
  // So we can Do some GPIO stuff  
  
  // Prescale the HFPERCLK -> HF/4 = 32/4 = 8Mhz 
  CMU_ClockDivSet(cmuClock_HFPER, cmuClkDiv_4);

  // Enable clock for GPIO module 
  CMU_ClockEnable(cmuClock_GPIO, true);
  
  // Enable clock for TIMER0 module
  CMU_ClockEnable(cmuClock_TIMER0, true);
  
  // Init the LEDs 
  GPIO_PinModeSet(gpioPortE,2,gpioModePushPull,0);
  
  //Select TIMER0 parameters 
  TIMER_Init_TypeDef timerInit =
  {
    .enable     = true, 
    .debugRun   = true, 
    .prescale   = timerPrescale1024, 
    .clkSel     = timerClkSelHFPerClk, 
    .fallAction = timerInputActionNone, 
    .riseAction = timerInputActionNone, 
    .mode       = timerModeUp, 
    .dmaClrAct  = false,
    .quadModeX4 = false, 
    .oneShot    = false, 
    .sync       = false, 
  };
  
  // Enable overflow interrupt
  TIMER_IntEnable(TIMER0, TIMER_IF_OF);
  
  // Enable TIMER0 interrupt vector in NVIC
  NVIC_EnableIRQ(TIMER0_IRQn);
  
  // Set TIMER Top value - Top Value / (8MHz / 1024 (prescaler))
  // For 2 Seconds Top Value= 15625
  TIMER_TopSet(TIMER0, 15625);
  
  /* Configure TIMER */
  TIMER_Init(TIMER0, &timerInit);
  
  while(1)
  {
    //We Sleep even if we wake up from the interrupt
    EMU_EnterEM1();
  }
}