Interrupt handling problem - Printable Version

Code:
/*=============================================================================================================================

 * @file    main.c

 * @author    

 * @brief    This is a testing program for the PULPissimo microcontroller that is implemented on a FPGA NEXYS4 board.

 *        There is a hardware abstraction layer, that was created for that board. This program helps to find out

 *        if everything is working as expected.

 * @date    2021-01-02

 * @version    v1.0

 ============================================================================================================================*/

//#include <stdio.h>

#include <stdint.h>

#include "HAL/hal_gpio.h"

#include "HAL/HAL_Defines.h"

#include "HAL/hal_timer.h"

#include "HAL/hal_interrupt.h"

#include "HAL/pulpissimo.h"

//#include <rt/rt_api.h>



//int __rt_fpga_fc_frequency = 20000000;

//int __rt_fpga_periph_frequency = 10000000;

//unsigned int __rt_iodev_uart_baudrate = 115200;



/**************************************************

 * @note   -

 * @brief  Callback function for timer interrupt.

 * @param  -

 * @return -

 ************************************************/

void callback_3(void)

{

  INT_MASK_R &= ~0x400; //disable timer interrupt line

  TIM_CFG_LO &= ~0x4;    //diasable timer interrupts

  INT_ACK_R  &= ~0x400; //clear interrupt ACK flag



  hal_gpio_toggle(LED0); //toggle LED0



  INT_CTR_R &= ~0x400; //clear pending interrupt flag

  INT_MASK_R |= 0x400; //enable timer interrupt line 

  TIM_CFG_LO |= 0x4;   //enable timer interrupts    

}



int main() 

{

  hal_gpio_init(LED0, OUTPUT); //init LED0

  hal_gpio_init(LED1, OUTPUT); //init LED1



  hal_gpio_write(LED0, LOW); //turn off LED0

  hal_gpio_write(LED1, LOW); //turn off LED1



  INT_MASK_R &= ~0xFFFFFFFF; //disable all interrupt lines

  INT_CTR_R  &= ~0xFFFFFFFF; //clear all pending interrupts

  TIM_CNT_LO &= ~0xFFFFFFFF; //set timer count register to zero

  

  hal_interrupt_set_handler(10, callback_3); //register callback function for timer interrupt



  hal_timer1_init(0, RTC_32KHZ, CONTINUE,CMP_RST);     //init timer 

  hal_timer1_set_cmp(0xFFFF);                //set timer compare register value            

  hal_timer1_en_int(1);                    //enable timer interrupts

  hal_timer1_start();                    //start timer



  while(1)

  {

    //checks if timer is running as expected

    if(TIM_CNT_LO >= 0xFFF)

    hal_gpio_write(LED1, 1);

    else

    hal_gpio_write(LED1, 0);

  }

  return 0;

}