//********************** ISR functions **************************************************
//void timer_interrupt_init (void* base, alt_u32 irq_controller_id, alt_u32 irq)
//{
//  /* Register the interrupt */
//  alt_ic_isr_register(irq_controller_id, irq, timer_interrupt_irq, base, NULL);
//
//  irq_cnt = 0;
//
//  /* Start timer */
//  IOWR_ALTERA_AVALON_TIMER_CONTROL(base, ALTERA_AVALON_TIMER_CONTROL_ITO_MSK
//  | ALTERA_AVALON_TIMER_CONTROL_START_MSK);
//}
//
//void timer_interrupt_irq (void* base)
//{
//  /* Clear TO bit in status register */
//  IOWR_ALTERA_AVALON_TIMER_STATUS (base, 0);
//
//  if (irq_cnt < 1000) {
//      irq_cnt++;
//  } else {
//      irq_cnt = 0;
//      send_tx_buffer(&tx);
//  }
//
//  /*Start timer */
//  IOWR_ALTERA_AVALON_TIMER_CONTROL(base, ALTERA_AVALON_TIMER_CONTROL_ITO_MSK
//  | ALTERA_AVALON_TIMER_CONTROL_START_MSK);
//
//}

#include <stdio.h>
#include "alt_types.h"
#include "system.h"
#include <sys/alt_irq.h>
#include "altera_avalon_timer_regs.h"

void timer_interrupt_latency_irq()
{
    IOWR_ALTERA_AVALON_TIMER_STATUS(TIMER_0_BASE,0);
    alt_ic_irq_disable(TIMER_0_IRQ_INTERRUPT_CONTROLLER_ID, TIMER_0_IRQ);
    printf("Hello timer!\n");
    alt_ic_irq_enable(TIMER_0_IRQ_INTERRUPT_CONTROLLER_ID, TIMER_0_IRQ);
    printf("IRQ enabled!\n");
}

int main()
{
    printf("Hello from Nios II!\n");
    /* Register the interrupt */
    alt_ic_isr_register(TIMER_0_IRQ_INTERRUPT_CONTROLLER_ID, TIMER_0_IRQ, timer_interrupt_latency_irq, TIMER_0_BASE, NULL);
    /* Start timer */
    IOWR_ALTERA_AVALON_TIMER_PERIODL(TIMER_0_BASE,10000);
    IOWR_ALTERA_AVALON_TIMER_PERIODL(TIMER_0_BASE,10000);
    IOWR_ALTERA_AVALON_TIMER_PERIODH(TIMER_0_BASE,1000);
    IOWR_ALTERA_AVALON_TIMER_CONTROL(TIMER_0_BASE, ALTERA_AVALON_TIMER_CONTROL_ITO_MSK
            | ALTERA_AVALON_TIMER_CONTROL_CONT_MSK
            | ALTERA_AVALON_TIMER_CONTROL_START_MSK);
    while (1);//Event Loop
    return 0;
}

alt_ic_irq_disable(TIMER_0_IRQ_INTERRUPT_CONTROLLER_ID, TIMER_0_IRQ);
...
alt_ic_irq_enable(TIMER_0_IRQ_INTERRUPT_CONTROLLER_ID, TIMER_0_IRQ);