interrupt problem

[Altera_Forum]

Hi all, 

i've modified the DE2 Media Computer demo, in order to register\play 2 different messages.  It works fine.  Then i've tried to add a blinking led adding an interval timer(period 1 sec, simple periodic interrupt) in my SOPC, but i've some problem with it:  - it blinks, but faster than 1 sec, and every 3 blinks, 1 is faster than the others - when i press a button, it stops blinking until i relese the button  I supposed that it was related with the IRQ number in SOPC builder, and i changed it to 0 for my interval timer...anything changed...  my code is:  # ifdef ALT_ENHANCED_INTERRUPT_API_PRESENT static void alt_avalon_timer_sc_irq (void* base)# else static void alt_avalon_timer_sc_irq (void* base, alt_u32 id)# endif { alt_irq_context cpu_sr; // clear the interrupt IOWR_ALTERA_AVALON_TIMER_STATUS (base, 0); illu_led = !illu_led; //switch a flag /* * Dummy read to ensure IRQ is negated before the ISR returns. * The control register is read because reading the status * register has side-effects per the register map documentation. */ IORD_ALTERA_AVALON_TIMER_CONTROL (base); // ALT_LOG - see altera_hal/HAL/inc/sys/alt_log_printf.h // ALT_LOG_SYS_CLK_HEARTBEAT(); /* * Notify the system of a clock tick. disable interrupts * during this time to safely support ISR preemption */ cpu_sr = alt_irq_disable_all(); alt_tick (); alt_irq_enable_all(cpu_sr); } //----------------------------------------------------- void alt_avalon_timer_sc_init (void* base, alt_u32 irq_controller_id, alt_u32 irq, alt_u32 freq) { // set the system clock frequency alt_sysclk_init (freq); // set to free running mode IOWR_ALTERA_AVALON_TIMER_CONTROL (base, ALTERA_AVALON_TIMER_CONTROL_ITO_MSK | ALTERA_AVALON_TIMER_CONTROL_CONT_MSK | ALTERA_AVALON_TIMER_CONTROL_START_MSK); // register the interrupt handler, and enable the interrupt # ifdef ALT_ENHANCED_INTERRUPT_API_PRESENT alt_ic_isr_register(irq_controller_id, irq, alt_avalon_timer_sc_irq, base, NULL);# else alt_irq_register (irq, base, alt_avalon_timer_sc_irq);# endif }and in my main function, inside while(1):   IOWR_ALT_UP_PARALLEL_PORT_DATA( RED_LEDS_BASE, illu_led); someone can help?