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Altera_Forum
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21 years ago

Nios stops responding to interrupts

Using Nios(3.2), Nios32@30mhz with some user logic modules in the C4. The simplest possible ISR will works a random number of times (< 30) and then stop working. The IRQ signal from the user logic is...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
21 years ago

This is because printf uses the timer irq and because your isr never clears it&#39;s irq&#39;s bit. Every time your irq returns the isr manager is going to service the next irq which is just a big switch statement, so your irq can and will lock up everything else.

If you really don&#39;t want to service your irq then you can change the priority of the timer irq and avoid this problem in most cases, but I fully recommend servicing your irqs.