Problem wid nios ii APIs

[Altera_Forum]

Hello all, 

I'm using Quartus v13.1 on my DE2-70 board with the cyclone II fpga. I want to enable interrupts using toggle switches. It worked when using the Altera ehanced interrrupt API (#include"altera_avalon_pio_regs.h"), However I tried using the nios 2 API (because we have some tutorials using it ) and It does not seem to work. For eg:   I tried using the functions such as : __builtin_wrctl(3, 2) and __builtin_wrctl(0, 1) to write into the ienable and status register respectively. When i read the ipending register (ipending = __builtin_rdctl(4)) it shows 0 . I also tried replacing it with the nios 2 macros without much success. Here is the code i used:  #include <stdint.h> #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include "system.h" #include "nios2.h" volatile uint32_t *LED = (volatile uint32_t *) LEDS_BASE; /* Green leds base address*/ volatile uint32_t * slides = (volatile uint32_t *) 0x41000; /* slider switches base address*/   void toggle_isr() {  int press;  press = *(slides+3); /* read the switch edge capture register*/  //*(slides+3) = 0; /* clear the interrupt */  printf("Hello from Nios 3! \n");  while(1)  {  printf("Hello from Nios I4! \n");  if ((press & (1 << 1)) != 0) /* SW[1] */  {  printf("Hello from Nios II! %d \n", *LED);  if(*LED == 0xFF)  *LED = 0;  (*LED)++;  usleep(100000);  }  } } void interrupt_handler(void) {  int ipending, status;  printf("Hi! \n");  NIOS2_READ_STATUS(status);  printf("HhgfghfjhgfghfI! %d \n", status);  NIOS2_READ_IPENDING(ipending);  printf("Hello from Nios II! %d \n", ipending);  //if (((ipending & (1 << 1))) != 0 ) // toggle switches is interrupt level 1  if (ipending != 0) // checking for enabled interrupts in general*/  {  printf("Hello from Nios 2! %d \n", ipending);  toggle_isr();  }  // else, ignore the interrupt  return; } int main() {  *(slides+2) = 0x3;   NIOS2_WRITE_IENABLE(0x2);   NIOS2_WRITE_STATUS(1); /* enable Nios II interrupts*/   interrupt_handler();  return 0; }   Is there a reason why it is not working (errors in the code above, obsolete functions …)?