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Altera_Forum's avatar
Altera_Forum
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19 years ago

NIOS program deadlocks

Hello folks, I have an interrupt-based NIOS II program and I'm using the DE2 board. My program works ok sometimes but it seems to deadlock randomly when pushbuttons are pressed or inputs fr...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
19 years ago

Hello, I have a few recommendations.

1. Get your reset address out of volatile memory.

- Point it at external flash, or at a pre-initialized "onchip" memory.

2. Get in and out of your ISRs as quickly as possible.

- Do a minimal amount of processing to determine the cause of the interrupt.

- Push any action off to the main loop of your code or a task (if using an OS).

- Follow the example(s) in Count Binary and Board Diagnostics for ISR creation, etc.

3. Are you sure your processor is deadlocked?

- It could be that you've set one of your input PIOs to generate level sensitive interrupts....and that level happens to be the default level of the input signal(s).

- It could also be that you're (somehow) generating a spurious interrupt. (This would be tricky, unless you're manually enabling an interrupt that does not yet have a handler).

Finally, it might help if you post some code illustrating where you suspect the problem(s) to be.

Best Regards,

- slacker