Nios II interrupt

Hi,

I am new to the Nios II core. I have built a simple system with a timer which is 
set as periodically timer. I have registered an interrupt service routine:

     alt_irq_disable(TIMER_0_IRQ);
     res = alt_irq_register(TIMER_0_IRQ, NULL, timer_isr);

With this code I still come in my installed ISR. So registering is also enable 
the interrupt. Is that correct, is there a way to register an ISR and leave the 
interrupt disabled (until you decide to enable it manually)?

Another question: where can I find a list with available routines for the 
peripheral. For instance, I saw in an example the call 
IOWR_ALTERA_AVALON_PIO_DATA to write to my io-pins. But where can I find a 
complete list. It not in the software developer's handbook.

best regards,
Frank

Frank van Eijkelenburg wrote:
> Hi,
> 
> I am new to the Nios II core. I have built a simple system with a timer 
> which is set as periodically timer. I have registered an interrupt 
> service routine:
> 
>     alt_irq_disable(TIMER_0_IRQ);
>     res = alt_irq_register(TIMER_0_IRQ, NULL, timer_isr);
> 
> With this code I still come in my installed ISR. So registering is also 
> enable the interrupt. Is that correct, is there a way to register an ISR 
> and leave the interrupt disabled (until you decide to enable it manually)?

Normally, you'll use the generated alt_sys_init() to set up the timers
in alt_main().  This wants to happen after the call to alt_irq_init(ALT_IRQ_BASE).
Take a look at the macros in alt_sys_init() to see the underlying process.

> 
> Another question: where can I find a list with available routines for 
> the peripheral. For instance, I saw in an example the call 
> IOWR_ALTERA_AVALON_PIO_DATA to write to my io-pins. But where can I find 
> a complete list. It not in the software developer's handbook.

Take a look in the components directory.  For example, for pios, take
a look at components/altera_avalon_pio/inc/altera_avalon_pio_regs.h.

Mark