smt32 interrupts. why my diode is not blinking?

I have smt32l1xx board and this code below is not working. Debugger shows pinA5 is set, but diode connected to this pin is still not lightening. I dont know why. Even i add delay after setting bit it is not working. diode is connected to PA5 and GND on board.

#include <stm32l1xx.h>

#define ENABLE 1
#define DISABLE 0


void TIM2_IRQHandler() //interrupt
{
 if (TIM_GetITStatus(TIM2, TIM_IT_Update) == SET)
 {
 TIM_ClearITPendingBit(TIM2, TIM_IT_Update);

 if (GPIO_ReadOutputDataBit(GPIOA, GPIO_Pin_5))
 GPIO_ResetBits(GPIOA, GPIO_Pin_5); //LED OFF
 else
 GPIO_SetBits(GPIOA, GPIO_Pin_5); //LED ON <- im here and still nothing

 }
}

int main(void)
{
    /* gpio init struct */
    GPIO_InitTypeDef gpio;
    TIM_TimeBaseInitTypeDef tim;
    NVIC_InitTypeDef nvic;
    /* reset rcc */
    RCC_DeInit();


    RCC_APB2PeriphClockCmd(RCC_AHBENR_GPIOAEN, ENABLE);
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);

    GPIO_StructInit(&gpio);
        /* use pin 0 */
        gpio.GPIO_Pin = GPIO_Pin_5;
        /* mode: output */
        gpio.GPIO_Mode = GPIO_Mode_OUT;
        /* apply configuration */
        GPIO_Init(GPIOA, &gpio);

     TIM_TimeBaseStructInit(&tim); //timer
     tim.TIM_CounterMode = TIM_CounterMode_Up;
     tim.TIM_Prescaler = 64000 - 1;
     tim.TIM_Period = 1000 - 1;
     TIM_TimeBaseInit(TIM2, &tim);

     TIM_ITConfig(TIM2, TIM_IT_Update, ENABLE);
     TIM_Cmd(TIM2, ENABLE);

     nvic.NVIC_IRQChannel = TIM2_IRQn; //interrupt
     nvic.NVIC_IRQChannelPreemptionPriority = 0;
     nvic.NVIC_IRQChannelSubPriority = 0;
     nvic.NVIC_IRQChannelCmd = ENABLE;
     NVIC_Init(&nvic);


     while (1)
     {

     }
    /* never reached */
    return 0;
}

To make sure that your hardware is properly initialized, you should use STM32CubeMX. It seems that the GPIOA clock is on the AHB bus, however you call RCC_APB2PeriphClockCmd which is for APB2. So try to use the equivalent for AHB something like RCC_AHBPeriphClockCmd